PROFESSIONAL AND BUSINESS REQUIREMENTS OF ARCHITECTS AND ENGINEERS BASIC INFORMATION AND TUTORIALS

This article is important for both the service provider and the client.

Management of the building process is best performed by the individuals educated and trained in the profession, that is, architects and engineers. While the laws of various states and foreign countries differ, they are consistent relative to the registration requirements for practicing architecture.

No individual may legally indicate to the public that he or she is entitled to practice as an architect without a professional certificate of registration as an architect registered in the locale in which the project is to be constructed.

This individual is the registered architect. In addition to the requirements for individual practice of architecture, most states and countries require a certificate of registration for a single practitioner and a certificate of authorization for an entity such as a corporation or partnership to conduct business in that locale.

An architect is a person who is qualified by education, training, experience, and examination and who is registered under the laws of the locale to practice architecture there. The practice of architecture within the meaning and intent of the law includes:

Offering or furnishing of professional services such as environmental analysis, feasibility studies, programming, planning, and aesthetic and structural design Preparation of construction documents, consisting of drawings and specifications, and other documents required in the construction process

Administration of construction contracts and project representation in connection with the construction of building projects or addition to, alteration of, or restoration of buildings or parts of building

All documents intended for use in construction are required to be prepared and administered in accordance with the standards of reasonable skill and diligence of the profession. Care must be taken to reflect the requirements of country and state statutes and county and municipal building ordinances.

Inasmuch as architects are licensed for the protection of the public health, safety, and welfare, documents prepared by architects must be of such quality and scope and be so administered as to conform to professional standards.

Nothing contained in the law is intended to prevent drafters, students, project representatives, and other employees of those lawfully practicing as registered architects from acting under the instruction, control, or supervision of their employers, or to prevent employment of project representatives from acting under the immediate personal supervision of the registered architect who prepared the construction documents.

CAMBER DEFINITION BASIC INFORMATION AND TUTORIALS

What Are Cambers?

Camber is a curvature built into a member or structure so that when it is loaded, it deflects to a desired shape. Camber, when required, might be for dead load only, dead load and partial live load, or dead load and full live load. The decision to camber and how much to camber is one made by the designer.

Rolled beams are generally cambered cold in a machine designed for the purpose, in a large press, known as a bulldozer or gag press, through the use of heat, or a combination of mechanically applied stress and heat.

In a cambering machine, the beam is run through a multiple set of hydraulically controlled rollers and the curvature is induced in a continuous operation. In a gag press, the beam is inched along and given an incremental bend at many points.

There are a variety of specific techniques used to heat-camber beams but in all of them, the side to be shortened is heated with an oxygen-fed torch.

As the part is heated, it tries to elongate. But because it is restrained by unheated material, the heated part with reduced yield stress is forced to upset (increase inelastically in thickness) to relieve its compressive stress.

Since the increase in thickness is inelastic, the part will not return to its original thickness on cooling. When the part is allowed to cool, therefore, it must shorten to return to its original volume. The heated flange therefore experiences a net shortening that produces the camber.

Heat cambering is generally slow and expensive and is typically used in sections larger than the capacity of available equipment. Heat can also be used to straighten or eliminate warping from parts. Some of these procedures are quite complex and intuitive, demanding experience on the part of the operator.

Experience has shown that the residual stresses remaining in a beam after cambering are little different from those due to differential cooling rates of the elements of the shape after it has been produced by hot rolling. Note that allowable design stresses are based to some extent on the fact that residual stresses virtually always exist.

Plate girders usually are cambered by cutting the web plate to the cambered shape before the flanges are attached.

Large bridge and roof trusses are cambered by fabricating the members to lengths that will yield the desired camber when the trusses are assembled. For example, each compression member is fabricated to its geometric (loaded) length plus the calculated axial deformation under load. Similarly, each tension member is fabricated to its geometric length minus the axial deformation.

SUB CONTRACTING DISPUTE RESOLUTION IN CIVIL ENGINEERING PROJECTS

The problems between main and sub-contractors were one of the areas to benefit most from Part II of the UK Government’s Housing Grants, Construction and Regeneration Act 1996 (see Section 1.6). The introduction of adjudication under that act to deal with disputes has at least allowed sub-contractors to press their claims to an earlier conclusion, and to challenge any withholding of payment by the contractor.

The Act requires payment terms to be stated and regular payments made. It prohibits ‘pay when paid’ clauses, and requires the contractor to issue a detailed ‘withholding notice’ if he seeks to hold back payment. These measures have eased the cash flow problems of sub-contractors.

Also most standard forms of sub-contract now contain provision for payment of interest on delayed payments, but this may not be very effective because a sub-contractor may not claim interest for fear the contractor might not as a consequence give him any further work.

The Civil Engineering Contractors Association (CECA) has issued a Form of Sub-contract ‘for use in conjunction with the ICE conditions of contract.’ Contractors are, of course, not obliged to use this form and many use one of their own devising or modify the standard form.

The provisions of the CECA sub-contract illustrate the many matters which such a sub-contract has to cover and the difficulty of trying to provide rights to the sub-contractor without putting the main contractor at risk under his contract.

Provisions of the CECA sub-contract, apart from defining the work, timing and duration of the sub-contractor’s input, require the sub-contract to set out the division of risks as between contractor and sub-contractor.

It defines procedures and methods of valuing variations made by the engineer and confirmed by the contractor, or made by the contractor; and sets out procedures for notification and payment for ‘unforeseen conditions’ or other claim matters. It also stipulates requirements for insurances and so on.

Many of the provisions are similar in terms to the ICE conditions applying to the contractor, and are thus passed on to the sub-contractor in respect of his work. The subcontractor is ‘deemed to have full knowledge of the provisions of the main contract’ and the contractor must give him a copy of it (without the prices) if the sub-contractor requests it.

Of particular importance is Clause 3 of the CECA sub-contract which requires the sub-contractor to carry out his work so as to avoid causing a breach of the main contract by the contractor. He has to indemnify the contractor ‘against all claims, demands, proceedings, damages, costs and expenses made against or incurred by the contractor by reason of any breach by the subcontractor of the sub-contract.’

But a sub-contractor undertaking a small value contract may find it impossible to accept this clause. If he fails to complete his work on time and this could possibly cause a delay to the whole project, he might be liable to pay many thousands of pounds to the contractor – far in excess of the value of his sub-contract.

A further problem for the engineer is that, if a dispute arises between the contractor and his sub-contractor as to who is responsible for some defective work, the defect can remain uncorrected until the dispute is resolved. If a defect is found after the sub-contractor has left site and he is believed or known to be responsible for it, the contractor may not be able to get the sub-contractor back to site to remedy the defect, or to pay for its repair.

To guard against this, the contractor may therefore hold back full payment to the sub-contractor for many months until a certificate of completion for the whole works is issued. This will cause another dispute between contractor and sub-contractor.

The development of sub-contracting in civil engineering has therefore brought both advantages and disadvantages. However, problems rarely arise if the contractor can use sub-contractors he has worked with before whose work has proved satisfactory and he treats them fairly.

SUB CONTRACTING ON CIVIL CIVIL ENGINEERING PROJECTS BASIC INFORMATION

What Is Sub Contracting?

Many civil engineering contractors now use sub-contractors to do much of their work. Most conditions of contract permit a contractor to sub-let work of a specialist nature; but the ICE conditions of contract have gone further and permit the contractor to sub-contract any part of the work (but not the whole of the work), subject only to notifying the engineer of the work sub-contracted and the name of the sub-contractor appointed to undertake it.

The contractor does not have to notify any labour-only sub-contracts he uses. The engineer can object, with reasons, to the appointment of a sub-contractor, but otherwise has no rights in connection with such sub-contracts, except that he can require removal of a sub-contractor who proves incompetent or negligent, or does not conform to safety requirements.

Under FIDIC conditions for overseas work, sub-contracting requires the engineer’s prior sanction. In building work there has long been a trend to pass the majority of work to sub-contractors who specialize in various trades, and the same has now occurred in civil engineering where many operations are ‘packaged up’ and sub-let.

Thus sub-contracts may be let for excavation, formwork, reinforcement supplied and erected, and concreting. The advantage to the contractor is that this reduces the staff he needs on site and his capital outlay on plant and equipment. He can use sub-contractors with proven experience and does not have to take on a range of temporary labour whose quality may be variable.

The contractor retains responsibility for the quality and correctness of work and, of course, has to plan and co-ordinate the sub-contract inputs, and often supply any necessary materials.

But if much of the work is sub-contracted, the contractor’s or agent’s main input to a project may be that of dealing with the sub-contracts and controlling their financial outcome, so these matters may take priority over dealing with any engineering problems which arise.

The contractor may therefore tend to leave a sub-contractor to solve any problems he encounters, on the basis that these are his risks under his sub-contract and it is up to him to deal with them. But the sub-contractor may think otherwise, so a dispute arises as each considers the other responsible for any extra cost or delays caused.

Frequent disputes have also arisen in recent years when any default or presumed default by a sub contractor has resulted in the contractor withholding payment to him. Late payment by contractors to sub-contractors is another widespread source of complaint by sub-contractors, but remedies are difficult to devise.

The sub-contracts are private contracts whose terms are unknown to the engineer and the employer, so they cannot interfere in any such dispute. The engineer has only power to protect nominated sub contractors, i.e. subcontractors he directs the contractor to use.

SETTING OUT VERTICALITY, TUNNELS AND PIPELINES IN CIVIL ENGINEERING PROJECTS

As a building rises the vertical alignment must also be controlled. This can be done by extending building centre lines at right angles to each other out to fixed points clear of the structure.

These lines can then be projected up the building and marked, allowing accurate measurements from these marks at each floor. Alternatively an optical plumb can be used to project a fixed point up through openings in the floors of the building so as to provide a set of reference points at each level.

The standard of setting out for tunnels must be high using carefully calibrated equipment, precise application and double checking everything. An accurate tunnel baseline is first set out on the surface using the methods described above. Transference of this below ground can be done by direct sighting down a shaft if the shaft is sufficiently large to allow this without distortion of sight-lines on the theodolite.

With smaller shafts, plumbing down may be used. A frame is needed either side of the shaft to hold the top ends of the plumb-lines and to allow adjustment to bring them exactly on the baseline. The plumb-line used should be of stainless steel wire, straight and unkinked, and the bob of a special type is held in a bath of oil to damp out any motion.

By this means the tunnel line is reproduced at the bottom of the shaft and can be rechecked as the tunnel proceeds. Many tunnels are nowadays controlled by lasers, the laser gun being set up on a known line parallel to the centre line for the tunnel and aimed at a target.

Where a tunnelling machine is used, the operator can adjust the direction of movement of the machine to keep it on target so that the tunnel is driven in the right direction. For other methods of tunnelling, target marks can be set on the soffit of rings, the tunnel direction being kept on line by adjusting the excavation and packing out any tunnel rings to keep on the proper line.

Lasers are also used in many other situations, usually for controlling construction rather than for original setting out since their accuracy for this may not be good enough. The laser beam gives a straight line at whatever slope or level is required, and so can be used for aligning forms for road pavements or even laying large pipes to a given gradient. For the latter, the laser is positioned at the start of a line of pipes and focused on the required base line.

As each new pipe is fitted into the pipeline a target is placed in the invert of the open end of the pipe, using a spirit level to find the bottom point, and the pipe is adjusted in line and level until the target falls on the laser beam. Bedding and surround to the pipe are then placed to fix the pipe in position.

Rotating lasers are also widely used and once set up give a constant reference plane at a known level. Use of a staff fitted with a reflector allows spot levels to be obtained anywhere in the area covered by the laser. Earthmoving equipment fitted with appropriate sensors can also be operated to control the level of excavation or filling with minimum input other than by the machine operator.

THE JOB OF ESTIMATOR ON CIVIL ENGINEERING PROJECTS

Most estimators begin their career doing quantity takeoff; as they develop experience and judgment, they develop into estimators. A list of the abilities most important to the success of an estimator follows, but it should be more than simply read through.

Any weaknesses affect the estimator’s ability to produce complete and accurate estimates. If individuals lack any of these abilities, they must (1) be able to admit it and (2) begin to acquire the abilities they lack. Those with construction experience, who are subsequently trained as estimators, are often most successful in this field.

To be able to do quantity takeoffs, the estimator must

1. Be able to read and quantify plans.

2. Have knowledge of mathematics and a keen understanding of geometry. Most measurements and computations are made in linear feet, square feet, square yards, cubic feet, and cubic yards. The quantities are usually multiplied by a unit price to calculate material costs.

3. Have the patience and ability to do careful, thorough work.

4. Be computer literate and use computer takeoff programs such as On-Screen Takeoff or Paydirt.

To be an estimator, an individual needs to go a step further. He or she must

1. Be able, from looking at the drawings, to visualize the project through its various phases of construction. In addition, an estimator must be able to foresee problems, such as the placement of equipment or material storage, then develop a solution and determine its estimated cost.

2. Have enough construction experience to possess a good knowledge of job conditions, including methods of handling materials on the job, the most economical methods of construction, and labor productivity. With this experience, the estimator will be able to visualize the construction of the project and thus get the most accurate estimate on paper.

3. Have sufficient knowledge of labor operations and productivity to thus convert them into costs on a project. The estimator must understand how much work can be accomplished under given conditions by given crafts. Experience in construction and a study of projects that have been completed are required to develop this ability.

4. Be able to keep a database of information on costs of all kinds, including those of labor, material, project overhead, and equipment, as well as knowledge of the availability of all the required items.

5. Be computer literate and know how to manipulate and build various databases and use spreadsheet programs and other estimating software.

6. Be able to meet bid deadlines and still remain calm. Even in the rush of last-minute phone calls and the competitive feeling that seems to electrify the atmosphere just before the bids are due, estimators must “keep their cool.”

7. Have good writing and presentation skills. With more bids being awarded to the best bid, rather than the lowest bid, being able to communicate what your company has to offer, what is included in the bid, and selling your services is very important. It is also important to communicate to the project superintendent what is included in the bid, how the estimator planned to construct the project, and any potential pitfalls.

People cannot be taught experience and judgment, but they can be taught an acceptable method of preparing an estimate, items to include in the estimate, calculations required, and how to make them. They can also be warned against possible errors and alerted to certain problems and dangers, but the practical experience and use of good judgment required cannot be taught and must be obtained over time.

How closely the estimated cost will agree with the actual cost depends, to a large extent, on the estimators’ skill and judgment. Their skill enables them to use accurate estimating methods, while their judgment enables them to visualize the construction of the project throughout the stages of construction.

CIVIL CONSTRUCTION PROJECT RISK AND MITIGATION

Samuel Johnson famously wrote that ‘to build is to be robbed’. Facing the same challenges, but with the benefit of hindsight, Pope Pius II praised his architect for ‘lying about the costs’ following budget overruns on the building of Pienza Cathedral, which threatened at the time to bankrupt the Vatican.

Both of these experiences suggest that clients have been and continue to be exposed to a significant degree of cost risk when undertaking construction projects. Invariably, they also pick up much of the financial consequences of decisions, omissions and mistakes made by others working on their behalf.

Decisions made at the outset of a project: investing in land, selecting one project opportunity in favour of others; confirming a brief; or establishing project governance could all potentially have a substantial impact on project outcomes, and as a result carry significant risk. Unfortunately, many of these early decisions have to bemade without the benefit of a considered design response and may, as a result, be sub-optimal.

Whilst it is important that advice given to clients early in a project should give the team some ‘wiggle room’ to develop a preferred solution, it is also important to work within project disciplines once these are established. Effective teamwork during the design development process between the designer and cost consultant can help to mitigate many of these potential risks.

Design stages

As a client’s brief and concept designs are developed, a greater degree of fixity in terms of the design solution and predicted costs can be provided by the project team. This process is discussed in more detail in the section focused on cost planning.

However, as the design develops and cost certainty increases, so does the cost of changing the design, and the client and project team’s resistance to change.

Risk and risk transfer

As a project progresses to the appointment of contractors, the client’s overall financial commitment becomes better defined. More risk can also be transferred to third parties if the client so wishes.

Whilst under most procurement routes the client is required to accept risks associated with design performance, they will generally seek to transfer commercial and construction risks to the contractor through some form of a fixed price, lump sum contract.

Quite clearly, if the design information upon which the client obtains a contractual commitment is not complete, is ambiguous or is not fully coordinated then, not only will the client retain outstanding design risk, but will also find that the basis of his commercial risk transfer to the contractor is weakened.

Evidence from Construction Key Performance Indicators, published by the DTI, indicates the scale of this potential problem, showing that fewer than 80% of projects are completed with #10% of their original tender sum. Moreover, only around 50% of projects are completed within #5% of the tender sum.

Whilst some of this cost variation may reflect client changes, or problems on site, it is likely that some of these increases will have resulted from the consequences of continuing design development. In order to mitigate the client’s risk, it is incumbent upon the team to ensure that the design is completed to the appropriate level of detail and fixity required by the procurement route. To do otherwise risks rendering some of the effort expended in design development and cost-planning abortive.

CAD APPLICATIONS IN CIVIL ENGINEERING BASIC AND TUTORIALS

AutoCAD

AutoCAD is the most widely used CAD software in civil engineering applications. In an effort toward computer-integrated construction (CIC), researchers have developed a link between AutoCAD and a knowledge-based planning program [Cherneff et al., 1991].

CATIA

CATIA is a three-dimensional solid modeling software marketed by IBM Corporation. Stone & Webster Engineering Corporation, in cooperation with IBM, developed an integrated database for engineering, design, construction, and facilities management. The system uses the DB2 relational database management system and the CATIA computer-aided-design software system [Reinschmidt et al., 1991].

Walkthrough™

Bechtel Corporation developed a three-dimensional simulation system called Walkthrough to aid in marketing, planning, and scheduling of construction projects. Walkthrough was developed to replace the use of plastic models as a design tool [Cleveland and Francisco, 1988].

It was designed to allow users to interact with a three-dimensional computer model as they would with a plastic model. The system uses three-dimensional, real-time animation that lets the user visually move through the computer model and observe visual objects.

Graphics of the system are presented such that objects are recognizable to  users not accustomed to typical CAD images. This includes the use of multiple colors and shading.

Walkthrough uses a Silicon Graphics IRIS workstation with specialized processors facilitating the high speed graphics required for real-time animation. This visualization and simulation system supports files from IGDS (Intergraph CAD system) and 3DM [Morad et al., 1992].

Object-Oriented CAD Model

An object-oriented CAD model for the design of concrete structures that uses EUROCODE2, a European standard for concrete structures, has been developed by German researchers. The primitive instancing solid-modeling technique was employed in the development of this object-oriented model [Reymendt and Worner, 1993].

A committee, entitled “NEW TECCMAR,” formed under the Japanese construction ministry, developed a three-dimensional finite-element method (FEM) program with an extended graphical interface to analyze general buildings [Horning and Kinura, 1993].

GREEN CEMENT BASIC AND TUTORIALS

GREEN CEMENT BASIC INFORMATION
What Are Green Cement?


The concrete industry is the largest user of natural resources in the world and thus has a considerable environmental impact. Each ton of Portland cement requires about 1.5 tons of raw material for its production.

This industry is not only energy intensive but is also a major contributor of greenhouse gases, in the form of CO2. Each ton of Portland cement that is produced involves the release into the atmosphere of about one ton of CO2.

Indeed, according to Mehta (1999), the cement industry is responsible for about 7% of global CO2 emissions; thus, there is considerable interest now in developing cements that are more environmentally friendly. One such cement (CEMROC), based on blast-furnace slag, has recently been described by Gebauer et al. (2005).

This cement, produced by Holcim in Europe, is reported to show close to zero CO2 emission during its production (only about 100 pounds per ton of cement).

It is similar to the supersulfated cement described above and is particularly well suited for use in structures exposed to aggressive environments. Other cements of this general type will almost certainly be developed in the future.

Another (and simpler) approach is to use much greater proportions of fly ash in concrete. A great deal of development is being conducted on what is referred to as high-performance, high-volume fly ash concrete (Malhotra, 2002; Malhotra and Mehta, 2002).

Such concretes may be defined as:

• Containing at least 50% fly ash by mass of the cementing materials
• Having a Portland cement content of less than 200 kg/m3
• Having a water content of less than 130 kg/m3
• Having a water/cementing materials ratio of less than 0.35

These concretes reach their full strength potential rather more slowly than conventional concretes, but the end result is a low-permeability, durable concrete.

INSTALLING METAL GUTTERS OF ROOFS CIVIL ENGINEERING TUTORIALS

INSTALLING METAL GUTTERS OF ROOFS CIVIL ENGINEERING BASICS
How To Install Metal Gutter Of Roof?

Installing Metal Gutters

Most metal gutters in residential drainage systems are installed with large spikes that pass through the sides and into the fascia board (Fig. 14-8).

A metal tube or sleeve, called a ferrule, mounts around the spike and maintains the spacing of the gutter sides. Locate these spikes 24 to 30 inches apart, depending on snow conditions.

Two other hanging methods can be used for metal gutters. Sickle-shaped hangers can be fastened to the fascia boards about every 30 inches. The gutters are laid on top of the hanger (Fig. 14- 9).

This method eliminates the need to drill holes in the gutter and thus is easier than spiking the gutters in place. The sickleshaped hangers are more expensive than spikes.

The second way to hang metal gutters is to use strap hangers. These hangers have flanges that are nailed in place under the roofing material (Fig. 14-10).

This type of hanger is best used on new work, since there is always a chance of damaging the existing roofing when it is pried up to install the hanger. Elbows usually connect outlet tubes and collector spouts.

Squeeze the end of the downspout and insert it into the large end of the elbow. Downspouts are fastened to the wall with downspout straps. Be sure the straps are long enough to anchor the downspout securely to the wall.

If the gap between the wall and the downspout is too wide, shim the downspout strap 1 inch away from the wall with a product that is weather-resistant or waterproof. Use two straps on each 10-foot length of downspout and three straps on two joined 10-foot sections.

To enable downspouts to perform their maximum service, install them so that they carry water as far away from the building’s foundation line as possible. This is very important—foundation problems are common triggers of very complex and expensive litigation.

There are several ways to achieve this, but the most popular are to use a concrete splash block directly under the downspout, which runs the water toward the driveway or a similar draining surface, or to connect the downspout directly to an underground line that leads to the storm sewer system.

REPEATED MECHANICAL LOADINGS: FATIGUE BASIC AND TUTORIALS

REPEATED MECHANICAL LOADINGS: FATIGUE BASIC INFORMATION
Effects Of Repeated Loadings

In the preceding sections we have considered the behavior of a test specimen subjected to an axial loading. We recall that, if the maximum stress in the specimen does not exceed the elastic limit of the material, the specimen returns to its initial condition when the load is removed.

You might conclude that a given loading may be repeated many times, provided that the stresses remain in the elastic range. Such a conclusion is correct for loadings repeated a few dozen or even a few hundred times.

However, as you will see, it is not correct when loadings are repeated thousands or millions of times. In such cases, rupture will occur at a stress much lower than the static breaking strength; this phenomenon is known as fatigue. A fatigue failure is of a brittle nature, even for materials that are normally ductile.

Fatigue must be considered in the design of all structural and machine components that are subjected to repeated or to fluctuating loads. The number of loading cycles that may be expected during the useful life of a component varies greatly.

For example, a beam supporting an industrial crane may be loaded as many as two million times in 25 years (about 300 loadings per working day), an automobile crankshaft will be loaded about half a billion times if the automobile is driven 200,000 miles, and an individual turbine blade may be loaded several hundred billion times during its lifetime.

Some loadings are of a fluctuating nature. For example, the passage of traffic over a bridge will cause stress levels that will fluctuate about the stress level due to the weight of the bridge. A more severe condition occurs when a complete reversal of the load occurs during the loading cycle.

The stresses in the axle of a railroad car, for example, are completely reversed after each half-revolution of the wheel. The number of loading cycles required to cause the failure of a specimen through repeated successive loadings and reverse loadings may be determined experimentally for any given maximum stress level.

If a series of tests is conducted, using different maximum stress levels, the resulting data may be plotted as a s-n curve. For each test, the maximum stress s is plotted as an ordinate and the number of cycles n as an abscissa; because of the large number of cycles required for rupture, the cycles n are plotted on a logarithmic scale.

A typical s-n curve for steel is shown in Fig. 2.16. We note that, if the applied maximum stress is high, relatively few cycles are required to cause rupture. As the magnitude of the maximum stress is reduced, the number of cycles required to cause rupture increases, until a stress, known as the endurance limit, is reached.

The endurance limit is the stress for which failure does not occur, even for an indefinitely large number of loading cycles. For a low-carbon steel, such as structural steel, the endurance limdecrease as the number of loading cycles is increased. For such metals, one defines the fatigue limit as the stress corresponding to failure after a specified number of loading cycles, such as 500 million.

Examination of test specimens, of shafts, of springs, and of other components that have failed in fatigue shows that the failure was initiated at a microscopic crack or at some similar imperfection. At each loading, the crack was very slightly enlarged.

During successive loading cycles, the crack propagated through the material until the amount of undamaged material was insufficient to carry the maximum load, and an abrupt, brittle failure occurred.

Because fatigue failure may be initiated at any crack or imperfection, the surface condition of a specimen has an important effect on the value of the endurance limit obtained in testing. The endurance limit for machined and polished specimens is higher than for rolled or forged components, or for components that are corroded.

In applications in or near seawater, or in other applications where corrosion is expected, a reduction of up to 50% in the endurance limit can be expected.is about one-half of the ultimate strength of the steel. For nonferrous metals, such as aluminum and copper, a typical s-n curve (Fig. 2.16) shows that the stress at failure continues to decrease as the number of loading cycles is increased. For such metals, one defines the fatigue limit as the stress corresponding to failure after a specified number of loading cycles, such as 500 million.

AXIAL LOADING; NORMAL STRESS BASICS AND TUTORIALS

AXIAL LOADING; NORMAL STRESS TUTORIALS
What Is Axial Loading? What Is Stress?

The deformation caused in a body by external forces or other actions generally varies from one point to another, i.e., it is not homogeneous. In fact, a homogeneous deformation is rare. It occurs, for example, in a body with isostatic supports under a uniform temperature variation or in a slender member under constant axial force.

Rod BC of the example considered in the preceding section is a two-force member and, therefore, the forces FBC and F'BC acting on its ends B and C (Fig. 1.5) are directed along the axis of the rod. We say that the rod is under axial loading.

An actual example of structural members under axial loading is provided by the members of the bridge truss shown in Photo 1.1.

Returning to rod BC of Fig. 1.5, we recall that the section we passed through the rod to determine the internal force in the rod and the corresponding stress was perpendicular to the axis of the rod; the internal force was therefore normal to the plane of the section (Fig. 1.7) and the corresponding stress is described as a normal stress.

Thus, formula (1.5) gives us the normal stress in a member under axial loading:

σ =P/A 

We should also note that, in formula (1.5), s is obtained by dividing the magnitude P of the resultant of the internal forces distributed over the cross section by the area A of the cross section; it represents, therefore, the average value of the stress over the cross section, rather than the stress at a specific point of the cross section.

To define the stress at a given point Q of the cross section, we should consider a small area DA. Dividing the magnitude of DF by DA, we obtain the average value of the stress over DA. Letting DA approach zero, we obtain the stress at point Q:

σ = lim dF/dA      as dA approaches infinity (1.6)

In general, the value obtained for the stress s at a given point Q of the section is different from the value of the average stress given by formula (1.5), and s is found to vary across the section. In a slender rod subjected to equal and opposite concentrated loads P and P' , this variation is small in a section away from the points of application of the concentrated loads, but it is quite noticeable in the neighborhood of these 

It follows from Eq. (1.6) that the magnitude of the resultant of the distributed internal forces is

∫dF = ∫σ dA     lower limit = A

But the conditions of equilibrium of each of the portions of rod require that this magnitude be equal to the magnitude P of the concentrated loads. We have, therefore,

P = ∫dF = ∫σ dA    lower limit = A

which means that the volume under each of the stress surfaces must be equal to the magnitude P of the loads. This, however, is the only information that we can derive from our knowledge of statics, regarding the distribution of normal stresses in the various sections of the rod. 

The actual distribution of stresses in any given section is statically indeterminate. To learn more about this distribution, it is necessary to consider the deformations resulting from the particular mode of application of the loads at the ends of the rod.

In practice, it will be assumed that the distribution of normal stresses in an axially loaded member is uniform, except in the immediate vicinity of the points of application of the loads. The value s of the stress is then equal to save and can be obtained from formula (1.5). 

However, we should realize that, when we assume a uniform distribution of stresses in the section, i.e., when we assume that the internal forces are uniformly distributed across the section, it follows from elementary statics† that the resultant P of the internal forces must be applied at the centroid C of the section. 

This means that a uniform distribution of stress is possible only if the line of action of the concentrated loads P and P' passes through the centroid of the section considered. This type of loading is called centric loading and will be assumed to take place in all straight two-force members found in trusses and pin-connected structures, such as the one considered in Fig. 1.1. 

However, if a two-force member is loaded axially, but eccentrically we find from the conditions of equilibrium of the portion of member that the internal forces in a given section must be equivalent to a force P applied at the centroid of the section and a couple M of moment M = Pd. The distribution of forces—and, thus, the corresponding distribution of stresses—cannot be uniform. Nor can the distribution of stresses be symmetric.

DRILLING A TILE WITHOUT CRACKING IT BASIC AND TUTORIALS

TILE DRILLING WITHOUT CRACKING THE TILE TECHNIQUES
How To Drill Tiles Without Cracking It?

This article is a step by step process in drilling tiles, without cracking it. Many installations in kitchens involve drilling through a tiled surface.

It is essential to use the correct technique for drilling through tiles so they do not crack. The dust created from drilling ceramic tiles can discolor grout and sealant so you may want to vacuum dust from holes as you drill them.


Tools and materials
Felt-tip pen
masking tape
drill and bits,
vacuum cleaner
wall plug

Steps


1. Mark the point for the hole using a felt-tip pen. Apply some masking tape over the mark—it should still be visible.

2. Fit a tile drill bit. Remember to switch off any hammer action.

Selecting a tile bit: Tile bits differ in shape based on material. The spear-shaped tip penetrates a tile, then enlarges the hole to the diameter of the tip’s base.

Caution: Take care when changing a bit after operating a drill: the bit may be hot. Wear gloves to avoid a burn.


3.  Position a vacuum cleaner below the mark and switch it on. Start up the drill on a low speed, and slowly increase the speed.

4. Once through the tile, change the bit for a masonry bit or wood bit, depending on the surface below. Drill to the required depth.

5. Remove the masking tape from the tile, then plug the hole with the appropriate wall plug, and insert the fastener as required.

Selecting wall plugs

Unless you are using masonry screws, a wall plug is required to secure a screw that is
inserted into masonry. The plugs shown here are masonry plugs, and the different colors relate to their width, or gauge.

Wall plugs are also needed to make strong connections in hollow walls such as stud walls; these are of a different design from those used in masonry.

PAYMENT REQUESTS AND CHANGE ORDERS ROLE OF ARCHITECT OR ENGINEER DURING CONSTRUCTION BASICS AND TUTORIALS

PAYMENT REQUESTS AND CHANGE ORDERS ROLE OF ARCHITECT OR ENGINEER DURING CONSTRUCTION BASIC INFORMATION
Payment Requests & Change Order Role Of Architects Or Engineers In Civil Projects


Payment Requests
The contractor normally submits a consolidated payment request monthly to the architect and client for review and certification.

The payment request should be subdivided by trade and compared with the schedule of values for each trade that would have been submitted with the subcontractor bid if required by the instructions to bidders and bid form.

The architect should review the payment request with respect to the percentage of completion of the pertinent work item or trade. Some clients or lending institutions require that a partial waiver of lien be submitted for each work item or trade with each payment request.

This partial waiver of lien can either be for the prior monthly request, which will indicate that the prior month’s payment has been received, or in certain cases for the current monthly request.

If the latter procedure is followed, the waiver may require revision, depending on the architect’s review, if a work-item or trade-payment request is modified.

The architect is not expected to audit the payment request or check the mathematical calculations for accuracy.

Change Orders
Contractor’s change-order requests require the input of the architect, engineer, and client and are usually acted on as part of the payment request procedure. A change order is the instrument for amending the original contract amount and schedule, as submitted with the bid and agreed on in the client-contractor contract.

Change orders can result from departures from the contract documents ordered during construction, by the architect, engineer, or client; errors or omissions; field conditions; unforeseen subsoil; or other similar conditions.

A change order outlines the nature of the change and the effect, if any, on the contract amount and construction schedule. Change orders can occur with both a zero cost and zero schedule change.

Nevertheless, they should be documented in writing and approved by the contractor, architect, and client to acknowledge that the changes were made, with no impact.

Change orders are also used to permit a material substitution when a material or system not included in the contract documents is found acceptable by the client and architect.

 For material substitutions proposed by the contractor, schedule revisions are not normally recognized as a valid change.

The sum of the change-order amounts is added or deducted from the original contract amount. Then, the revised contract amount is carried forward on the contractor’s consolidated application for payment after the change orders have been signed by all parties.

The normal contractor payment request procedure is then followed, on the basis of the new contract amount. If the schedule is changed because of a change order, the subsequent issue of the construction schedule should indicate the revised completion or move-in date, or both, that result from the approved change.

SITE RECORD KEEPING, INSPECTION & TESTING ROLE OF ARCHITECT OR ENGINEER DURING CONSTRUCTION BASICS AND TUTORIALS

SITE RECORD KEEPING, INSPECTION & TESTING ROLE OF ARCHITECT OR ENGINEER DURING CONSTRUCTION BASIC INFORMATION
Site Record Keeping, Inspection, and Testing Role Of Architect Or Engineer During Civil Projects


Site Record Keeping
Depending on contractual requirements for service during the construction phase, the architect may establish a field office.

In this event, dual record keeping is suggested between the site and architect’s office so that records required for daily administration of construction are readily accessible on site.

Contractor correspondence, field reports, testing and balancing reports, shop drawings, record documents, contractor payment requests, change orders, bulletin issues, field meeting minutes, and schedules are used continually during construction.

Computer systems and electronic mail make the communication process somewhat easy to control.

Inspection and Testing
Technical specifications require testing and inspection of various material and building systems during construction to verify that the intent of the design and construction documents is being fulfilled under field conditions.

Testing is required where visual observations cannot verify actual conditions. Subsurface conditions, concrete and steel testing, welding, air infiltration, and air and water balancing of mechanical systems are such building elements that require inspection and testing services.

Normally, these services are performed by an independent testing agency employed directly by the client so that third-party evaluation can be obtained.

Although the architect does not become involved in the conduct of work or determine the means or methods of construction, the architect has the general responsibility to the client to see that the work is installed in general accordance with the contract documents.

Other areas of inspection and testing involve establishing and checking benchmarks for horizontal and vertical alignment, examining soils and backfill material, compaction testing, examining subsurface retention systems, inspecting connections to public utilities, verifying subsoil drainage, verifying structural column centerlines and base-plate locations (if applicable), checking alignment and bracing of concrete formwork, verifying concrete strength and quality, and other similar items.

SITE OBSERVATION - ROLE OF ARCHITECT OR ENGINEER DURING CONSTRUCTION BASICS AND TUTORIALS

SITE OBSERVATION - ROLE OF ARCHITECT OR ENGINEER DURING CONSTRUCTION BASIC
Site Observation Role Of Architect Or Civil Engineer During Civil Projects


Site Observation
As part of their ongoing services during construction, and depending on the scale and complexity of the project, architects and engineers may make periodic site visits or maintain full-time representation on site during a portion or all of the construction period.

The professional’s role is to expedite day-to-day communication and decision making by having on-site personnel available to respond to required drawing and specification clarifications.

Site-observation requirements for the project should be discussed with the client at the onset of the project and be outlined in the architect-client agreement. Many clients prefer periodic or regularly scheduled site visits by the design professional.

A provision for additional or full-time on-site representation, however, can be addressed in the agreement, and compensation for this additional service can be outlined in the agreement for discussion with the client later in the development process or during the construction phase.

The client and the architect and engineer should agree on the appropriate amount of site visitation provided in the architect’s basic services to allow adequate site-observation services based on specific project conditions.

If periodic site observations are made, the architect should report such observations to the client in written form. This should call attention to items observed that do not meet the intent of the construction documents.

It is normally left to the client to reject or replace work unless such defective work involves life safety, health, or welfare of the building occupants or is a defect involving structural integrity.

If the architect provides full-time site observation services, daily or weekly reports should be issued to the client outlining items observed that are not in accordance with the construction documents or design intent.

QUALITY CONTROL FOR ARCHITECTS AND ENGINEERS BASICS AND TUTORIALS

QUALITY CONTROL FOR ARCHITECTS AND ENGINEERS BASIC INFORMATION
What Are Quality Controls For Architects And Engineers?


To maintain a consistently high level of quality in design and construction documentation, a rigorous internal review of the documents prepared by the architect or engineer, which draws on the full depth and experience of resources available, should be undertaken during the contract document phase.

Quality control can begin in the earliest stages of design, when criteria are established and developed as design guidelines for use throughout the project. At each stage of development, a coordination checklist, based on previous experience, can be utilized for the project through an independent internal or external technical checking program.

Computer file management may be used to enable the various technical disciplines to share graphic data and check for interference conditions, thereby enhancing technical coordination of the documents. Quality control should also continue throughout the construction phase with architect and engineer review of shop drawings and on-site observation of the work.

Quality Management Program.
To have a truly meaningful quality management program, all personnel must be committed to it. To help the professional staff understand the quality program, quality systems should be developed, updated, maintained, and administered to assist the architect and professional staff in providing quality service to clients.

An individual in each office may be assigned to assist in the quality management program. This person should undertake to instill in all personnel the importance of such a program in every aspect of the daily conduct of business.

The quality management program should set quality goals; develop professional interaction for meeting these goals among peers and peer groups; review building systems, specifications, and drawings to ensure quality; and see that these objectives are known to the public.

Such a program will result in a client base that will communicate the quality level of the architect to others in the community, profession, and international marketplace.

The architect’s image is of extreme importance in acquiring and maintaining clients, and the best quality management program focuses on client service and dedication to the profession.

BEST CIVIL AND STRUCTURAL ENGINEERING SCHOOL/ UNIVERSITIES IN THE WORLD IN 2011

CIVIL AND STRUCTURAL ENGINEERING SCHOOL/ UNIVERSITIES BEST IN THE WORLD
QS World University Ranking Best Civil and Structural Engineering School In The World For 2011

MIT tops the first ever QS World University Ranking® for Civil and Structural Engineering, which also sees a top-five performance from Imperial College London and two Asian universities in the top ten.

A diverse top 20 features nine universities from the US, three from the UK, two from Singapore, and one apiece from Japan, Switzerland, Australia, the Netherlands, China and Canada.

Below is the Top 20 Universities in the World for Civil and Structural Engineering:

1. Massachusetts Institute of Technology (MIT) United States
2. Stanford University United States
3. University of Cambridge United Kingdom
4. University of California, Berkeley (UCB) United States
5. Imperial College London United Kingdom
6. University of Oxford United Kingdom
7. National University of Singapore (NUS) Singapore
8. The University of Tokyo Japan
9. California Institute of Technology (Caltech) United States
10. ETH Zurich (Swiss Federal Institute of Technology) Switzerland
11. The University of Melbourne Australia
12. University of Illinois at Urbana-Champaign United States
13. Delft University of Technology Netherlands
14. University of California, Los Angeles (UCLA) United States
15. University of Texas at Austin United States
16. Cornell University United States
17. Tsinghua University China
18. Nanyang Technological University (NTU) Singapore
19. University of Michigan United States
20. University of Toronto Canada

Metrics for the selection are its contribution to the Academe, Rate of Employment, and its Citations received.
For the Complete List, read this site.

COST ESTIMATING ON CIVIL ENGINEERING PROJECTS BASIC AND TUTORIALS

COST ESTIMATING ON CIVIL ENGINEERING PROJECTS BASIC INFORMATION
How To Make Cost Estimates For Civil Engineering Projects?


In carrying out cost management there should be a clearly defined route from feasibility stage through to the placement of a contract. There should be break points, or gateways, when the client can take the decision whether to proceed or not.  This is in line with the recommendations by the Office of Government Commerce in their Gateway Review Process.

One of the benefits of cost management in the pre-contract stage, especially in multicontract projects, is that it helps the project team to better establish the appropriate project contract strategy. That is, which work should be placed in which contract and possibly the form of contract which should be adopted for particular contracts.

Cost management can also help identify possible programme restraints both in contract preparation and execution. The preparation of the first estimate would be based on a variety of techniques, for example, historic data or approximate quantities.

Major projects often have substantial elements that are unique and for which there is no relevant historic data. In these cases it is necessary to analyse the project in as many individual work sections as can be identified, if possible to prepare indicative quantities and consider the resources necessary to carry out the work.

During this indicative stage it is wise to contact potential contractors and manufacturers especially with
regard to order-of-cost estimates for specialist sections.

Other matters that have an effect on cost and need to be addressed at this time include location of project and access thereto, especially with regard to heavy and large loads, availability of labour and the possible need for residential hostels or other accommodation for workmen, off-site construction, temporary works. It will also be necessary to consider allowances for design development, allowances for consultants’ fees and client’s costs, land-acquisition costs and general contingencies.

When the client has accepted the first estimate and instructs that the project proceed to the next stage, then this becomes the first cost plan against which further design developments and changes are monitored.

During the process of design development the main duties of the quantity surveyor as part of the cost management team are as follows: to check and report the cost of design solutions as they are established or refined by the engineers;  to prepare comparative estimates of various design solutions or alternatives and advise the engineer accordingly;  as changes are introduced into the project, to estimate the cost effect of the change and to report;  to prepare a pre-tender estimate based on a bill of quantities (BofQ) or priced activities;  to prepare a financial appraisal.


The monthly issue of the updated cost plan is the vehicle whereby the cost management team is made aware of the current estimated cost of the project. In its simplest form a pre-contract cost plan will set out in tabular form each and every work section, the approved estimate for that section, the estimate for the previous and the current month for the section and a note of the changes that have taken place in the month. The total of all the sections provides the estimated cost of the project.

There should be a continuous dialogue between the designers and the quantity surveyor (QS); ideally both should work together in the same office during the critical stages of design development. Normally, there are so many changes within a month during design development that these are better listed as an appendix to the cost plan.

One national client insists that a separate appendix to the cost plans lists all potential changes and these have to be approved by his project manager before changes can be included in the cost plan. In this way the cost plan represents committed cost only (Shrimpton, 1988).

The extent of detail in the preparation and updating of cost plans is such that it is best handled on a database for transfer to a spreadsheet.

The accepted estimate in the form of priced activities or BofQs becomes the basis for the first post-contract cost plan. This then acts as the client’s design datum for cost management and reporting in the construction stage.

Civil Engineering Design And Construct - A Guide To Integrating Design Into The Construction Process Free E-Book Download Link

Free E-Book Download Link of Civil Engineering Design And Construct - A Guide To Integrating Design Into The Construction Process

This publication is a guide to best practice in managing the project process in civil engineering design and construct (D&C) projects. It discusses the issues to be addressed when managing design and explains the attitudes and practices that are recommended to enable projects to succeed. 

It is intended to increase awareness and understanding of the issues involved, identifying what decisions need to be made, when and why. Differences between D&C and traditional procurement routes are highlighted along with contractual issues.

"Design and construct" is taken to be a generic term encompassing the whole family of design, construct, finance, own, operate and transfer procurement strategies, in which one party is responsible for both designing and constructing a facility. 

This includes projects procured under the Private Finance Initiative (PFI). Considerable emphasis is placed on imparting awareness of the importance of the designer-constructor interface as, in a D&C project, the most critical lines of communication are at this interface. 

As well as describing contractual frameworks, this guide also contains management toolboxes for reference. It is a working document that will assist those at a senior level (clients, contractors and consultants alike) who have to make crucial decisions affecting the outcome of a project.

DOWNLOAD LINK!!!