Blog Archives

Repair and Replacement of Sign Panels

Posted by on 22/ 11/ 15

The decision on the appropriate action for damaged sign panels is a field judgment. Minor bending of a sign will prevent headlights from illuminating the sign at night. Signs with minor bends can be repaired by removing the sign from the post and straightening the sign. Signs that are badly bent cannot be properly repaired in the field. Attempts to straighten badly bent signs result in cracking and peeling of the sign face material. Many agencies consider it more economical to replace rather than repair signs that maintenance workers judge to be badly worn or damaged [46].

There are field repair kits available with pressure-sensitive reflective background sheeting and die-cut pressure-sensitive prespaced letters, borders, and symbols...

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Finite Element Method

Posted by on 22/ 11/ 15

The basic idea of the finite element method is to divide the field to be analysed into sub-domains, the so-called finite elements, of simple shape: e. g. triangles, quadrilaterals with linear, parabolic or cubic sides for two-dimensional analysis. In each finite element, an analytically simple equation is postulated for the vari­able to be determined, i. e. the coordinate or displacement for solid mechanics, and the fluid pressure, temperature or concentration for diffusion problems. In order to obtain continuity, the unknown variable field has to be continuous at the limit between finite elements. This requirement is obtained thanks to common values of the field at specific points, the so-called nodes, which are linking the finite elements together...

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Bathtubs

Posted by on 22/ 11/ 15

Bathtubs for handicap use are required to have a seat. The seat may be built in or a detachable model. Grab bars with a minimum length of 24 inches must be mounted against the back wall, in line with each other and parallel to the floor. One of the bars, the top one, must be mounted a minimum of 33 inches and a maximum of 36 inches above the finished floor. The lower bar must be mounted 9 inches above the flood-level rim of the bathtub. A grab bar must be mounted at each end of the bathtub, with the bars being the same height as the top bar on the back wall. The bar used on the faucet end of the tub must be at least 24 inches long. A bar mounted at the other end of the tub must be at least 12 inches long. Faucets must be mounted below the grab bar...

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Techniques to Reduce Vandalism

Posted by on 22/ 11/ 15

Techniques to reduce incidents of sign vandalism include steps that address the reasons

for vandalism, enable the prosecution of offenders, ease maintenance, and make it more

difficult to perform the vandalism. Consider the following to reduce vandalism:

• The theft and damage to many street name signs is due to the similarity to someone’s name. Vandalism to signs can often be reduced by adding St., Ave., or Blvd. to the sign.

• Use only standard signs. Signs that have an unusual message experience a higher vandalism rate.

• Use sign blank materials that are less susceptible to specific types of vandalism. Thicker-gage aluminum sign blanks can be used in areas that are subject to damage by bending. Plywood sign blanks are less susceptible to gunshots...

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PREPARING FOR A JOB

Posted by on 22/ 11/ 15

The best way to make any project start smoothly is to adequately prepare for the job. This means spending time looking over the plans, and organizing information, and talking with whoever is overseeing the job before you start working on the job site.

Often, the lead framer does this preparation the night or morning before a job starts. You’ll find that the work will flow more smoothly if you begin preparation earlier and do it right.

If you’re a carpenter working for a framing contractor or a general contractor, many of the preparation tasks listed in this chapter will be done for you. If, on the other hand, you are the lead framer, framing contractor, and home builder all in one, then it’s up to you to get these done.

In this chapter, the word superintendent refers to the person on the j...

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Bath Water Found to be Culprit in Copper Toxicity Case

Posted by on 22/ 11/ 15

When F. W. was 63 years old she was seen by Dr. Elliott for a chronic vaginal discharge that had per­sisted for five years. She had been previously eval­uated by several healthcare practitioners for this problem. Although her gynecologist had been unable to find evidence of a yeast or bacterial in­fection, the patient was nevertheless placed on a variety of antibiotics, which seemed to exacerbate the problem.

During the interview, it was discovered that the patient’s symptoms seemed to improve when shetraveled. Shewentontodisclosethata rash she had all over her body also improved while she was away from home. She concluded that her symp­toms were probably related to stress, although there were no obvious new stressors in her life that could have accounted for this peculiar reaction.

Wh...

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SIGN VANDALISM PROBLEMS AND COUNTERMEASURES

Posted by on 22/ 11/ 15

Sign vandalism costs millions of dollars each year in increased maintenance costs and is a contributing cause to many accidents as well. In addition to the accident itself, van­dalized signs can expose the roadway agency and municipality to tort liability cases. Surveys of state and local agencies indicate that an average of 30 percent of all sign replacement and repair is due to vandalism and that an average of 30 percent of the sign maintenance budget is required for vandalized signs. Acts of sign vandalism are categorized as destruction, mutilation, and theft [16].

7.11.1 Destruction

Destruction occurs when the sign support or sign face is physically damaged to the extent that it no longer serves its intended purpose. Destruction vandalism includes damage from

• Gunshot

• Thrown proj...

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Creep Tests

Posted by on 22/ 11/ 15

Encouraging results of SMA resistance to deformation are being confirmed both in laboratory tests and on trial sections of pavements in operation. Clearly, in the majority of cases an SMA mixture is actually better than asphalt concrete (AC). Conversely, not every test method confirms that SMA possesses the better charac­teristics. The outcome depends on the loading mode and conditions of testing. The SMA tests resulting in divergent outcomes include

• Uniaxial creep test with a constant load (also called static creep), unconfined

• Uniaxial creep test with a repeated mode of loading (also called dynamic creep or repeated load axial test [RLAT]), unconfined

The classic versions of both tests have been carried out on 100 mm diameter speci­mens with a 100 mm loading platen (the so-calle...

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Latin hypercube sampling technique

Posted by on 22/ 11/ 15

The Latin hypercube sampling (LHS) technique is a special method under the umbrella of stratified sampling that selects random samples of each random variable over its range in a stratified manner. Consider a multiple integral involving K random variables

G = g (x) fx (x) d x = E [g (X)] (6.91)

J xeE

where X = (X1, X 2,…, XK )t is an K-dimensional vector of random variables, and fx(x) is their joint PDF.

The LHS technique divides the plausible range of each random variable into M(M > K in practice) equal-probability intervals. Within each interval, a single random variate is generated resulting in M random variates for each random variable. The expected value of g(X), then, is estimated as

1 M

G = g( X 1m, X 2m, …, XKm ) (6.92)

m=1

where Xkm is the variate generated for the kth random vari...

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Numerical Tools: The Finite Element Method

Posted by on 22/ 11/ 15

11.2.1 Introduction

An approximated solution of most problems described by a set of partial differential equations may be obtained by numerical methods like the finite element method (FEM), the discrete element method (DEM), the finite difference method (FDM), the finite volume method (FVM), or the boundary element method (BEM). For the problems concerned here, the most commonly used methods are the finite element and the finite difference procedures. Commonly, non-linear solid mechanics is better solved using the finite element method. Boundary element methods have strong limitation in the non-linear field. Finite difference methods are not easy to apply to tensorial equations (with the exception of the FLAC code, developed by Itasca).

Diffusion and advection-diffusion problems are often ...

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