Essential guide to the steel square pdf download

Providing this information to your supplier will set up an excellent opportunity to generate an accurate quote and help you identify and plan around potential obstacles.

Understand your needs: Blast-resistant buildings are excellent structures for cafeterias, break rooms, tool sheds, equipment storage, and spaces for offices, permitting, or security. Identifying specific operations and trades that drive improved cost-efficiencies while being located in the hazard areas is a starting point for understanding their importance.

Capacity: Headcount drives the quantity of blast-resistant buildings needed. The dimensions of blast-resistant buildings are wide-ranging. Knowing your headcount tells you what size building is required. Hazards: Recognizing the hazards and specifying correctly rated blast-resistant buildings are critical for creating safe and compliant spaces.

Access: Standard blast-resistant buildings are large. Access for truck delivery and crane offloading should be planned.

That starts with your vendor understanding curfews, limits, and clearances on public roads leading to a facility. Then, identifying any overhead or width clearances inside the facility is critical. Layout: If space is limited in the work zone, proper sequencing and layout of units optimize the space. Ensuring the buildings arrive on-site in the correct order is a critical element. In the staging portion of a project, there is typically not much lay-up space available to leave large buildings sitting temporarily.

Additionally, units with working plumbing require a potable water supply and waste connection. On short-term projects, power can come from generators or site supply.

Networking into a facility's communication network is generally straightforward. Identifying utility sources and their locations is a critical piece of the planning process. Timing: Establishing start and end dates will provide cost-certainty and allow the blast-resistant building supplier to adequately plan for availability, delivery, and pickup. High utilization during certain times of the year can limit availability.

Demobilization: Like all projects, having a vision for a strong finish ensures a clean, organized completion. Efficiently disconnecting utilities and cleaning the units allow for an organized, staggered schedule of trucks arriving to remove units from the site as quickly as the crane and rigging crew can safely lift, place and secure each unit.

Before pulling the trigger on purchasing or leasing a blast resistant building, this section gives you a guideline of the important questions to ask your vendor that can save you from headaches. The science of blast-resistant building design is no longer a new science, but it is still true that not all blast resistant building makers have tested their designs.

Make sure your blast-resistant building design has been taken off the drawing board and successfully blast-tested under the supervision of a well credentialed engineer. There's no shame in asking about your vendor's "experts" - who they are and about their training and background. Do they have years of experience in the science of blast-resistant design, or did they take a three day course to qualify them? There are many interpretations of the term blast-tested, but a successfully blast-tested building has the proven ability to actually save lives.

Pay special attention to duration and psi ratings when you review blast test reports because different applications call for different specifications. A laboratory blast-resistant building placed next to a blowdown stack should carry a higher rating, such as 8 psi, while a guard shack placed at the perimeter of your facility may only need a 3- to 5-psi rating. If a structure survives a blast but its interior walls, lights or other fixtures create shrapnel, the risk of casualties is still high.

Always ask blast-resistant building vendors to provide data and rationale for nonstructural items including wall and ceiling finishes, light fixtures, plumbing fixtures, cabinets, placement of open shelving and placement of any intake points. The following items are too technical to cover in the context of an online article but should be on your list of discussions to initiate with any blast-resistant building vendor.

Response level ratings have been established to predict the extent of repair resources needed after an explosion. It's crucial to study the response level table, then take a very close look at any blast-resistant module's response rating for a given duration and psi as proven through actual blast testing.

Another thing to consider just before making your purchase is what happens after the sale. Is it just a matter of waiting? Will you get updates? Will the timeline change? Is my sales rep still the main contact? The next step is project management and experienced vendors and manufacturers of blast resistant buildings should be able to paint a picture of what that process will look like.

Once a purchase order PO is received, the project is handed over to the project management group. Not all POs are accepted immediately. Sometimes the blast-resistant building manufacturer requires changes in the contract language, or there could be details to be clarified before the PO is formally accepted.

Occasionally, some new specs may show up in this stage. For example, the purchasing agent may not have clarified the type of HVAC system required or whether the system should be redundant. Before the PO is accepted, the building vendor will send it back with language defining these types of details, and the customer will need to approve the additional details. Depending on the complexity of the changes, and the responsiveness of those involved, getting the PO approved could take between a few days and a few weeks.

The project manager will do what they can to ensure the process keeps moving until both parties sign-off on the PO. Once the purchase order is formally accepted, the floor plan is emailed to the customer for review, and an initial kick-off meeting is scheduled. The kick-off meeting gives the salesperson the opportunity to introduce the customer to the project manager, and for the project manager to begin talking about expectations for the project.

During the kick-off meeting, the customer has reviewed the floor plan in advance, allowing for more design conversations to begin. In this meeting, there will also be a detailed review of the architectural, mechanical, electrical, plumbing, structural, and blast components of the building.

Additional meetings may be required for each of these components of the blast-resistant building. Once the project is under the care of the project manager, the original salesperson will be relatively hands-off unless their assistance is needed.

For example, their assistance may be required to discuss change orders or commercial changes, which occur when there are customer-driven changes that result in an increase or decrease to the contract price.

The important part is to keep an open channel for communication flowing. Project sizes can vary from simple single unit buildings, which may be ready in a matter of weeks, to large multi-section complexes which could take months, or the better part of a year.

The best way to find out the timeline is to ask about the specific details for your project. As a general rule, ask questions. How will the project be managed? What happens if we have change orders? Will this change affect my projected delivery date? Once the blast-resistant building is installed, regular maintenance and any issues that come up are handled by a qualified service department. Once the kick-off meeting has occurred, initial introductions have been made, and the customer signs off on the floor plan, then things begin to move forward.

This will help the process run in a timely manner. Other meetings that will need to occur and places where other approvals may come into play will be when discussing the architectural, mechanical, electrical, plumbing, structural, and blast components of the building. Each of these components will need to be reviewed and approved using detailed pdf files.

These drawings will call out the placement and specifications for each of these elements, which were not detailed on the floor plan. Each build-site is different as far as requirements for blast-resistant buildings. Some states have strict environmental guidelines California comes to mind , some follow another set of standards, like OSHA or other federal, local, or regional guidelines. Your blast-resistant building manufacturer will be responsible for ensuring that the building meets all requirements of the local authority having jurisdiction LAHJ and will set up any third-party reviews that need to happen.

These requirements could add things like fire sprinklers, devices to improve air quality or emissions, or any number of details meant to protect the occupants of the building. It is the responsibility of the vendor to know and expect these requirements.

Because they are modular in nature, the construction of blast-resistant buildings happens before they ever get to your site. This is one of the greatest benefits of modular construction. During the construction phase, the customer will get updates as needed, including progress photos.

A typical build, for example, a simple three-plex or smaller, may take weeks from the time drawings are approved.

Other complex projects will take more time. Your vendor should be able to talk in more detail about this, based on the specs of your individual project.

The last thing to happen while the building is still at the vendor site is the factory acceptance test. Some customers may choose to do a final onsite walk-through; others may give approval based on photos of the finalized building.

This can typically be done in a day. Once the final walk-through has happened, there will be no time wasted before the build is on the road. If the building is a multi-plex, it could take several trucks to get it to its final destination.

Some companies have their own transportation fleet, while others rely on outside sources. And some will use a combination of their own trucks and third-party transportation sources.

According to the project managers at RedGuard, working through the design process without delays is the biggest challenge in managing blast-resistant building projects.

Designing a building requires a lot of information and input from the customer. Sometimes there is information that is not available during the bid phase. Examples of some information that may not be available before the PO is issued are things like the actual electrical load requirements for equipment that is supplied by the customer, the expected use for each room in the building, and final details like color or finish selections.

Waiting on these things can slow down the initial design process. Once the end-users become involved, they may have valuable information or knowledge of the project that will require changes during the initial review. Following the advice here, as well as keeping the lines of communication open, and the team informed, will serve you well. At RedGuard, we design and build blast-resistant buildings and have been doing it since All the related details are on our minds every day, for at least 40 hours a week, but we know that our customers have more to think about.

When a highway is located in a cut section, the backslope may be traversable depending on its relative smoothness and the presence of fixed obstacles. If the foreslope between the roadway and the base of the backslope is traversable 1V:3H or flatter and the backslope is obstacle-free, it may not be a significant obstacle, regardless of its distance from the roadway. On the other hand, a steep, rough- sided rock cut normally should begin outside the clear zone or be shielded.

A rock cut normally is considered to be rough-sided when the face will cause excessive vehicle snagging rather than provide relatively smooth redirection.

A common obstacle on roadsides are transverse slopes created by median crossovers, berms, driveways, or intersecting side roads. Although the exposure for transverse slopes is less than that for foreslopes or backslopes, they generally are more critical to errant motorists because run-off-the-road vehicles typically strike them head-on.

Transverse slopes of 1V:lOH are desirable 7 ; however, their practicality may be limited by width restrictions and the maintenance problems associated with the long tapered ends of pipes or culverts. Transverse slopes of 1V:6H or flatter are suggested for high-speed roadways, particularly for the section of the transverse slope that is located immediately adjacent to traffic 3.

This slope then can be transitioned to a steeper slope as the distance from the edge of the through traveled way increases. Transverse slopes steeper than 1V6H may be considered for urban areas or for low-speed facilities.

Figures and show suggested designs for these slopes, while Section 3. Figure shows some alternative designs for drains at median openings. The water flows into a grated drop inlet in the median to a cross-drainage structure or directly underneath the travel lanes to an outside channel. This eliminates the two pipe ends that would be exposed to traffic in the median. The transverse slopes of the median opening then would be desirably sloped at 1V:1OH or flatter.

Suggested Design for Transverse Slopes. Traffic -. Safety treatment of culverts as discussed in Section 3. A drainage channel is an open channel usually paralleling the roadway. The primary function of drainage channels is to collect sur- face runoff from the roadway and areas that drain to the right-of-way and convey the accumulated runoff to acceptable outlet points. Channels should be designed to carry the design runoff and to accommodate excessive storm water with minimal highway flooding or damage.

However, channels also should be designed, built, and maintained with consideration given to their effect on the roadside en- vironment. Figures and present preferred foreslopes and backslopes for basic ditch configurations Cross sections shown in the shaded region of each figure are considered to have traversable cross sections. Channel sections that fall outside the shaded region are considered less desirable and their use should be limited where high-angle encroachments can be expected, such as the outside of relatively sharp curves.

Channel sections outside the shaded region may be acceptable for projects having one or more of the following characteristics: restrictive right-of-way environmental constraints; rugged terrain; resurfacing, restoration, or rehabilitation 3R projects; or low-volume or low-speed roads and streets, particularly if the channel bottom and backslopes are free of any fixed objects or located beyond suggested clear-zone distance.

Preferred Channel Cross Section 0. FLAT 0 0. If practical, drainage channels with cross sections outside the shaded regions and located in vulnerable areas may be reshaped and converted to a closed system culvert or pipe or, in some cases, shielded by a traffic barrier.

Information from various jurisdictions for the use of roadside barrier to shield non-traversable channels within the clear zone is included in Chapter 5. A basic understanding of the clear-zone concept is critical to its proper application. The suggested clear-zone distances in Table are based on limited empirical data that then were extrapolated to provide data for a wide range of conditions. Thus, the distances. In some cases, it is reasonable to leave a fixed object within the clear zone; in other instances, an object beyond the clear-zone distance may require removal or shielding.

Use of an appropriate clear-zone distance amounts to a compromise between maximizing safety and minimizing construction costs. Appropriate application of the clear-zone concept often will result in more than one possible solution. The following sections intend to illustrate a process that may be used to determine if a fixed object or non-traversable terrain feature should be relocated, modified, removed, shielded, or remain in place.

The guidelines in this chapter may be most applicable to new construction or major reconstruction. On 3R projects, the primary em- phasis is placed on the roadway itself. The actual performance of an existing facility may be evaluated through an analysis of crash records and on-site inspections as part of the design effort or in response to public input from road users and other stakeholders.

It may not be cost-effective or practical to bring a 3R project into full compliance with all of the clear-zone width recommendations provided in this Guide because of environmental effects or limited right-of-way. Because of the scope of such projects and the limited funding available, emphasis should be placed on correcting or shielding areas in the project with identifiable safety problems related to clear- zone widths.

Bodies of water and steep cliffs are the types of areas that may be considered for special emphasis. The suggested clear-zone distance for recoverable foreslopes of lV:4H or flatter may be obtained directly fiom Table On new construction or major reconstruction, smooth slopes with no significant discontinuities and no protruding fixed objects are desirable from a safety standpoint.

It also is desirable to have the top of the slope rounded so an encroaching vehicle remains in contact with the ground It also is desirable for the toe of the slope to be rounded to improve traversability by an errant vehicle. The flatter the selected slope, the easier it is to mow or otherwise maintain and the safer it becomes to negotiate. Examples at the end of this chapter illustrate the application of the clear-zone concept to recoverable foreslopes.

However, a clear runout area beyond the toe of the non-recoverable foreslope is desirable because many vehicles on slopes this steep will continue on to the bottom. The extent of this clear runout area could be determined by first finding the available distance between the edge of the through traveled way and the breakpoint of the recoverable foreslope to the non-recoverable foreslope, as previously shown in Figure This distance then is subtracted from the suggested clear-zone distance based on the steepest recoverable foreslope before or after the non-recoverable foreslope and should be at least 3 m [lo ft] if practicable.

The result is the desirable clear runout area that should be provided beyond the non-recoverable foreslope if practical. Such a variable sloped typical section often is used as a compromise between roadside safety and economics.

By providing a relatively flat recovery area immediately adjacent to the roadway, most errant motorists can recover before reaching the steeper foreslope beyond.

The foreslope break may be liberally rounded so that an encroach- ing vehicle does not become airborne. The steeper slope also may be made as smooth as practical and rounded at the bottom. Figure illustrates a recoverable foreslope followed by a non-recoverable foreslope. Example 3-C demonstrates the method for calculating the desirable runout area. Critical foreslopes are those steeper than 1V3H 5. These slopes create a higher propensity for an errant vehicle to overturn and should be treated if they begin within the clear-zone distance of a particular highway and meet the suggested barrier recommenda- tions for shielding contained in Chapter 5.

Examples 3-C, 3-D, and 3-E illustrate the application of the clear-zone concept to critical foreslopes. A variable foreslope often is specified on new construction to provide a relatively flat recovery area immediately adjacent to the road- way followed by a steeper foreslope. This design requires less right-of-way and embankment material than a continuous, relatively. If the suggested clear-zone distance as determined from Table exists on the flatter foreslope, the steeper slope then may be critical or non-traversable.

Clear-zone distances for embankments with variable foreslopes ranging from essentially flat to 1V4H may be averaged to produce a composite clear-zone distance. Slopes that change from a foreslope to a backslope cannot be averaged and should be treated as drainage channel sections and analyzed for traversability as shown previously in Figures and Although a weighted average of the foreslopes may be used, it is preferable to use values in Table that are associated with the steeper slope.

If one foreslope is significantly wider, the clear-zone computation based on that slope alone may be used.

Roadside hardware should not be located in or near ditch bottoms or on the backslope near the drainage channel Any vehicle leaving the roadway may be h e l e d along the drainage channel bottom or encroach to some extent on the backslope, thus making an impact more likely. Breakaway hardware may not function as designed if the vehicle is airborne or sliding sideways when contact is made.

Non-yielding fixed objects should be located beyond the suggested clear-zone distance for these cross sections as determined from Table The clear zone for the through travel lanes includes the width of the auxiliary lanes. The clear zone for auxiliary lanes should be based on its design speed, traffic volume, horizontal curvature where appropriate, as discussed previously in Section 3.

For speed- change lanes, the design speed should be determined using the speed reached Va as determined from the minimum acceleration and deceleration lengths for ramp terminals provided in Chapter 10 of AASHTO's A Policy on Geometric Design for Highways and Streets 4. The speed from Chapter 10 should be rounded.

A separate clear zone is not necessary for speed-change lanes on conven- tional highways and where the auxiliary lane does not h c t i o n as a through lane e.

Refer to Example at the end of this chapter for an example of a freeway speed-change lane. The suggested clear-zone distance along the ramp may be based on the speed, volume, horizontal curvature, and roadside geometry along the ramp. Because ramps are of limited length, often contain very sharp curves, and tend to be overdriven by motorists, design- ers should use a conservative approach to determining the clear-zone distance.

For the purpose of determining this suggested clear- zone distance, the design speed along the ramp proper, which excludes a transition curve of m [I ft] or greater, should be determined from the simplified curve formula in Chapter 3 of AASHTO's A Policy on Geometric Design for Highways and Streets 4. Transition curves of m [I ft] or more can act as extensions of the speed-change lane and should have speeds similar to the adjacent tangent or speed-change lane. For simple ramps, such as loop and diagonal ramps, the design speed and volume of the ramp proper should be used to determine the suggested clear-zone distance.

When compound and reverse curves are used, the clear-zone distance recommended for the higher- speed curve excluding transition curves may be used for the entire ramp.

Refer to Example 3-K for more detailed information. For complex ramps with multiple radii and variable operating speeds, a separate clear-zone distance may be determined for each unique segment of the ramp. Refer to Example 3-L for more detailed information. Alternately, clear zones for ramps may be set at 9 m [30 ft] if previous experience with similar projects or designs indicates satisfac- tory experience. This method provides a consistent template that can be more practical to design and maintain.

Effective drainage is one of the most critical elements in the design of a highway or street. However, drainage features should be designed and built while considering their consequences on the roadside environment. In addition to drainage channels, which were. In general, the following options, listed in order of preference, are applicable to all drainage features: Eliminate non-essential drainage structures a Design or modify drainage structures so they are traversable or present a minimal obstruction to an errant vehicle If a major drainage feature cannot be effectively redesigned or relocated, shield it by using a suitable traffic barrier if it is in a vulnerable location The remaining sections of this chapter identify the safety problems associated with curbs, pipes and culverts, and drop inlets, and they offer recommendations about the location and design of these features to improve their safety characteristics without adversely affecting their hydraulic capabilities.

The information presented applies to all roadway types and projects; however, as with many engineering applications, the specific actions taken at a given location often rely heavily on the exercise of good engineeringjudgment and on a case-by-case assessment of the costs and benefits associated with alternative designs. Curb designs are classified as vertical or sloping. Vertical curbs are those having a vertical or nearly vertical traffic face mm [6 in.

They are intended to discourage motorists from deliberately leaving the roadway. Sloping curbs are those having a sloping traffic face mm [6 in. Sloping curbs, especially those with heights of mm [4 in. Curbs higher than mm [4 in. However, if higher curbs are used, they are not normally regarded as fixed objects that would require mitigation. In general, curbs are not desirable along high-speed roadways 9.

If a vehicle is spinning or slipping sideways as it leaves the road- way, wheel contact with a curb could cause it to trip and overturn. In other impact conditions, a vehicle may become airborne, which may result in loss of control by the motorist. The distance over which a vehicle may be airborne and the height above or below normal bumper height attained after striking a curb may become critical if secondary crashes occur with traffic barriers or other roadside ap- purtenances.

Refer to Section 5. When obstructions exist behind curbs, a minimum lateral offset of 0. A minimum lateral offset of 0. This lateral offset should not be construed as a clear-zone distance. Because curbs do not have a significant redirectional capability, obstructions behind a curb should be located at or beyond the suggested clear-zone distances shown in Table In many instances, obtaining the suggested clear-zone distances on existing facilities will not be feasible.

On new construction for which suggested clear-zone dis- tances cannot be provided, fixed objects should be located as far from the traveled way as practical on a project-by-project basis, but in no case closer than 0. Cross-drainage structures are designed to carry water underneath the roadway embankment and vary in size from mm 18 in.

Typically, their inlets and outlets consist of concrete headwalls and wingwalls for the larger structures and beveled-end sections for the smaller pipes. Although these types of designs are hydraulically efficient and minimize erosion problems, they may represent an obstacle to motorists who run off the road. This type of design may result in either a fixed object protruding above an otherwise traversable embankment or an opening into which a vehicle can drop, causing an abrupt stop.

The options available to a designer to minimize these obstacles are 11 : Using a traversable design, Extending the structure so that it is less likely to be hit, and.

Shielding the structure. Each of these options is discussed in the following subsections. To maintain a traversable foreslope, the preferred treatment for any cross-drainage structure is to extend or shorten it to intercept the roadway embankment and to match the inlet or outlet slope to the foreslope For small culverts, no other treatment is required.

For cross-drainage structures, a small pipe culvert is a single round pipe with a mm in. Extending culverts to locate the inlets or outlets a fixed distance from the through trav- eled way is not recommended if such treatment introduces discontinuities in an otherwise traversable slope. Extending the pipe results in the warping of the foreslopes in or out to match the opening, which produces a significantly longer area that affects the motorist who has run off the road.

Matching the inlet to the foreslope is desirable because it results in a much smaller target for the errant vehicle to hit, reduces erosion problems, and simplifies mowing operations.

Single structures and end treatments wider than 0. Modifications to the culvert ends to make them traversable should not significantly decrease the hydraulic capacity of the culvert. Safety treatments should be hydraulically efficient. To maintain hydraulic efficiency, it may be necessary to apply bar grates to flared wingwalls, flared end sections, or culvert extensions that are larger than the main barrel.

The designer should consider shielding the structure if significant hydraulic capacity or clogging problems could result. Full-scale crash tests have shown that automobiles can traverse cross-drainage structures with grated-culvert end sections constructed of steel pipes spaced on mm [30 in. This spacing does not significantly change the flow capacity of the culvert pipe unless debris accumulates and causes partial clogging of the inlet.

This underscores the importance of accurately assessing the clogging potential of a structure during design and the importance of keeping the inlets free of debris. Figure shows recommended sizes to support a full-sized automobile and is based on a mm [in. More recently, two full-scale crash tests were conducted to examine the safety performance of a 6. The first test involved a P pick-up truck impacting the upstream portion of the grate. The second test involved an C small car striking the culvert grate with the left-side tires while the right-side tires encountered the slope above the grate.

These scenarios were determined to be the worst testing conditions. This testing clearly demonstrated that the culvert safety grate recommended in Figure meets the safety performance evaluation guidelines set forth in NCHRP Report for a test level 3 TL-3 device. Further, these findings clearly support historical studies that show culvert grates provide the most cost-beneficial safety treatment for cross-drainage culverts. It is important to note that the toe of the foreslope and the ditch or stream bed area immediately adjacent to the culvert should be more or less traversable if the use of a grate is to have any significant safety benefit.

For median drainage where flood debris is not a concern and where mowing operations are frequently required, much smaller open- ings between bars may be tolerated and grates similar to those commonly used for drop inlets may be appropriate.

In addition, both the hydraulic efficiency and the roadside environment may be improved by making the culverts continuous and adding a median drainage inlet. This alternative eliminates two end treatments and is usually a practical design when neither the median width nor the height of fill is excessive.

Figure shows a traversable pipe grate on a concrete box culvert constructed to match the 1V:6H side slope. For intermediate-sized pipes and culverts whose inlets and outlets cannot be readily made traversable, designers often extend the structure so the obstacle is located at or just beyond the suggested clear zone. While this practice reduces the likelihood of the pipe end being hit, it does not completely eliminate that possibility. If the extended culvert headwall remains the only significant fixed object immediately at the edge of the suggested clear zone along the section of roadway under design and the roadside is generally traversable to the right-of-way line elsewhere, simply extending the culvert to just beyond the suggested clear zone may not be the best alternative, particularly on freeways and other high-speed, access-controlled facilities.

On the other hand, if the roadway has numerous fixed objects, both natural and man-made, at the edge of the suggested clear zone, extending individual structures to the. However, redesigning the inlet or outlet so that it is no longer an obstacle is usually the preferred safety treatment.

Each mm [30in. The safety pipe runners are Schedule 40 pipes spaced on centers of mm [30in. For major drainage structures that are costly to extend and whose end sections cannot be made traversable, shielding with an appropri- ate traffic barrier often is the most effective safety treatment.

Although the traffic barrier is longer and closer to the roadway than the structure opening and is likely to be hit more often than an unshielded culvert located farther from the through traveled way, a properly designed, installed, and maintained barrier system may provide an increased level of safety for the errant motorist. Parallel drainage culverts are those that are oriented parallel to the main flow of traffic.

They typically are used at transverse slopes under driveways, field entrances, access ramps, intersecting side roads, and median crossovers.

Most of these parallel drainage cul- verts are designed to carry relatively small flows until the water can be discharged into outfall channels or other drainage facilities and carried away from the roadbed. However, these drainage features can present a significant roadside obstacle because they can be struck head-on by impacting vehicles. As with cross-drainage structures, the designer's primary concern should be to design generally traversable slopes and to match the culvert openings with adjacent slopes.

On low-volume or low-speed roads, where crash history does not indicate a high number of run- off-the-road occurrences, steeper transverse slopes may be considered as a cost-effective approach.

Using these guidelines, safety treatment options are similar to those for cross-drainage structures, in order of preference: 1. Eliminate the structure. Use a traversable design. Move the structure laterally to a less vulnerable location. Shield the structure. Delineate the structure if the above alternatives are not appropriate. Unlike cross-drainage pipes and culverts that are essential for proper drainage and operation of a road or street, parallel pipes some- times can be eliminated by constructing an overflow section on the field entrance, driveway, or intersecting side road.

To ensure proper performance, care should be taken when allowing drainage to flow over highway access points, particularly if several access points are closely spaced or the water is subject to freezing.

This treatment usually will be appropriate only at low-volume locations where this design does not decrease the sight distance available to drivers entering the main road. Care also should be exercised to avoid erosion of the entrance and the area downstream of the crossing. This usually can be accomplished by paving the overflow section assuming the rest of the facility is not paved and by adding an upstream and downstream apron at locations where water velocities and soil conditions make erosion likely.

Closely spaced driveways with culverts in drainage channels are relatively common as development occurs along highways approach- ing urban areas.

Because traffic speeds and roadway design elements are usually characteristic of rural highways, these culverts may constitute a significant roadside obstacle. In some locations, such as along the outside of curves or where records indicate concentra- tions of run-off-the-road crashes, it may be desirable to convert the open channel into a storm drain and backfill the areas between adjacent driveways. This treatment will eliminate the ditch section as well as the transverse slopes with pipe inlets and outlets.

As emphasized earlier in this chapter, transverse slopes should be designed while considering their effect on the roadside environment. The designer should try to provide the flattest transverse slopes practical in each situation, particularly in areas where the slope has shown a high probability of being struck head-on by a vehicle. Once this effort has been made, parallel drainage structures should match the selected transverse slopes and, if possible, should be safety treated when they are located in a vulnerable position relative to main road traffic.

Although many of these structures are small and present a minimal target, the addition of pipes and bars perpen-. Research has shown that for parallel drainage structures, a grate consisting of pipes set on mm [24 in.

It also is recommended that the center of the bottom bar or pipe be set at to mm [4 to 8 in. Generally, single pipes with diameters of mm [24 in. When a multiple pipe installation is in- volved, however, a grate for smaller pipes may be appropriate. Reference may be made to the Texas Transportation Institute Research Study , Safe End Treatment for Roadside Culverts 13 , in which researchers concluded that a passenger vehicle should be able to traverse a pipelslope combination at speeds up to 80 k m h [50 mph] without rollover.

To achieve this result, the roadway or ditch foreslope and the driveway foreslope both should be 1V:6H or flatter and have a smooth transition between them.

Ideally, the culvert should be cut to match the driveway slope and fitted with cross members perpendicular to the direction of traffic flow as described previously. This study suggests that it could be cost-effective to flatten the approach slopes to 1V6H and match the pipe openings to these slopes for all sizes of pipes up to mm [36 in.

The addition of grated inlets to these pipes was considered cost-effective for pipes mm [36 in. Because these numbers were based in part on assumptions by the researchers, they should be interpreted as approxi- mations and not as absolute numbers.

Figure illustrates a possible design for the inlet and outlet end of a parallel culvert. When channel grades permit, the inlet end may use a drop-inlet type design to reduce the length of grate required. A mm [ in. The recommended grate design may affect culvert capacity if significant blockage by debris is likely; however, because capacity is not normally the governing design criteria for parallel structures, hydraulic efficiency may not be an overriding concern.

A report issued by the University of Kansas suggests that a 25 percent debris blockage factor should be sufficiently conservative to use as a basis for culvert design in these cases 8. This report also suggests that under some flow conditions, the capacity of a grated culvert may be. In those locations where headwater depth is critical, a larger pipe should be used or the parallel drainage structure may be positioned outside the clear zone, as discussed in the following section.

Some parallel drainage structures can be moved laterally farther from the through traveled way. This treatment often affords the designer the opportunity to flatten the transverse slope within the selected clear-zone distance of the roadway under design.

The Editors reserve the right to reject papers without sending them out for review. The IJERT is not limited to a specific areas of science and engineering but is instead covers wide range of branches of engineering and sciences. The major subject areas covered by the journal are following:. There is no any fee associated with submission to this journal. Almost all university and colleges research in both science and engineering is performed as a component of the advanced education of students.

Planking and strutting Planking and strutting - Earthwork support which include the use of timber Planking and strutting to uphold the sides of excavation, plywood trench sheeting and light steel trench sheeting and strutting. It is measured to the sides of trenches and given as an item.

Concrete in foundations including adjustment shall be given in cubic meters as stating the mix and thickness SMM F3. The adjustment of excavated soil disposal will be taken with this item i.

Backfill and Add. Removal from site Remove from site Remove from site 2. Reinforcements — Bar reinforcement will be entered by length on the dimension sheets and are billed in kilogrammes.

Mild steel bars in fdn footing Formwork section F19 Formwork for most of the surfaces are given in square meters classifying them in groups according to the position requiring formwork. Removal from site Example: Measurement of blockwork 8. Backfill 9. Remove from site 9. Backfill ……x 0. Remove from site …….. Damp proof course — Normally measured in linear meter.

It is measured in square meters if it does not exceed mm thick, otherwise it is in cubic meters. Damp proof membrane — This is laid on top of the hardcore and normally measured in square meter. Including levellg and compacting. Membrane not less than 0. The floors will be measured together with the associated items such as reinforcements Section F16 and formwork section F19 For a simple building, superstructure elements are such as walling, roofing, floors, doors, windows, staircases, fittings, electrical installation, plumbing installation etc.

Any additional areas of the external wall such as gables parapets, wall up to higher eaves level, etc, will be then taken off. In measuring the wall the measurer takes the whole area regardless that there are some voids and the adjustment of wall for window and doors openings will be made when measuring the windows and doors. A careful check should be made on the type and thickness of each partition, and where there are a number of different types of partition it is often helpful to color each type in a different color on the floor plan.

Internal wall is also measured in square meters stating all essential particulars as before described. Both types can conveniently be subdivided into two main sections for purposes of measurement, i. The order of measurement of these two sections varies in practice, but on balance it is probably better to take the construction first as this follows the order of construction on site.

Another alternative is to calculate the length by multiplying the natural secants of the angle of pitch by half the total span of the roof. The natural secants of the more usual pitches of the roof are as follows:- The use of four figure mathematical table for values of natural secants is recommended.

Furthermore, the asphalt item is to include the underlay of felt, cork, fiberboard or similar material and any reinforcement. Full particulars of felt are to be given such as extent of laps, nature The measurement of the main areas of roof covering will be followed by such linear items. The classifications depend on which kind of materials eg. Concrete blockwork background v Preparatory work so as to form keys e.

Floor and paving S 3 - Horizontal floor and paving , cross falls and slopes not exceeding 15 degrees from horizontal shall be given separately in square meters Ceiling Finishing S 4 Work to walls and ceilings shall each be given separately in square meters describing if to battering walls, to sloping walls etc. The area of ceiling is measured between wall surfaces in square meters, followed by any associated labor such as arises to beams.

Work behind wood skirting and the like shall be dealt with the work of walls disregarding any ground. Skirting and picture rails S. Dividing strips S. DOORS Door shutters The measurement of doors can be subdivided into internal and external doors, and the dimensions of each of these two classes of door broken down into; 1.

Door 2. Pannelled doors with open panels for glass shall be so described. Holes in timber — Holes for bolts and the like shall each be enumerated separately stating the size of bolts and the thickness of timber. Iron-mongery Particulars of the following shall be given:- Kind and quality of Iron-mongery Surface finish Nature of the background e. Those of similar character may be grouped together. Drawers shall be enumerated stating the overall dimensions, the thickness of component parts and the method of joining.

Applied covering — In square meters stating the method of securing. Kind and quality of material 2. Nature of work e. Nature of base on which work is executed 4. Preparatory work- rubbing down, repairing cracks, scrubbing 5. Number of priming or sealing coats 6. Number of undercoat 7. Number of finishing coat Purposes of bill of quantities a It enables all contractors tendering for a job to price on exactly the same information with a minimum effort.

In the absence of a bill of quantities being prepared by the building owner each contractor would have to preparing his own Bill of Quantities in the limited amount of time allowed for tendering. These places a heavy burden on each contractor and also involve him, in additional costs. Forms of Bills of Quantities Elemental bills In Elemental bills, items are grouped according to their position in the building.

Each element comprises an integral part of the building such as external walls, roofs or floors, which each perform a certain design of function. Within each element, the items, may be billed in trade order or grouped in building sequence. Sectionalized Trades bills This can be presented either as a trade bill or with elements as the main subdivision. Operational bills The description of the billed work follows the actual building process, with materials shown separately from labour, all described in terms of the operations necessary for the construction of the building.