Loads upgrades

Ascend and descend grades slowly. When ascending or descending grades in excess of 10 percent, drive the loaded forklift with the load upgrade. 

Grades must be ascended or descended slowly. When ascending or descending grades in excess of ten percent, loaded trucks must be driven with the load upgrade. On all grades the load and load-engaging means must be tilted back, if applicable, and raised only as far as necessary to clear the road surface. 

Figure 10-10. Keep a load upgrade and the forks pointed downgrade when no load is present. (Courtesy of the Clark Material Handling Company)...

Note that the maintenance of water quaUty and hence stream standards are not static, but subject to change with the municipal and industrial environment. For example, as the carbonaceous organic load is removed by treatment, the detrimental effect of nitrification in the receiving water increases. Eutrophication may also become a serious problem in some cases. These considerations require an upgrading of the required degree of treatment. 

Carriers and the chemical industry are working together to improve transportation safety. The American Association of Railroads has agreed to designate routes that handle 10,000 loads per year or more of chemicals as Key Routes." Routes designated as Key Routes will receive upgraded track, enhanced equipment to detect flaws in equipment or in trackage, and lower speed limits. 

The necessary skills should be on-site to attend to any minor faults but must not be allowed to alter settings from one test to another, except as required by the test procedure. Dummy loads should be ready for use. If sensitive equipment is to be present (as might be the case in upgrading computer room plant) then the interested parties must agree limits previously. This may also apply to parts of the plant itself such as humidity-detecting elements. The latter can be protected physically. The job specification should state which parts of the procedure apply (if not all). 

Upgrade to the existing facility depends on the increase in blast capacity required. Level of blast protection is generally based on building category, function, risk level and blast loads. Structural assessment and cost evaluation are then made to determine the best alternative to use. 

The upgraded masonry walls perpendicular to the blast loads can also serve as shear walls. They should be analyzed for in-plane shear and bending according to the procedure outlined in Chapter 7. Connections between shear wall and diaphragm or foundation must also be evaluated. 

There are other options for upgrading existing CMU masonry walls. One option would be to add steel members between the frame to reduce the vertical spans of the wail. Steel members should normally be tied to the existing wall. If they are not, then rebound load should be evaluated. 

Some reduction of reflected overpressure results within a horizontal distance of about twice the barrier wall height. Beyond this distance, the effects of a barrier wail is virtually nil. Quantification of the pressure reduction is difficult and often times requires sophisticated computer modeling. Normally, it is more cost effective to upgrade the strength of the structure to be protected than it is to construct a barrier wall. This is especially true when the structure of interest does not have sufficient blast capacity in the roof to resist the blast load. 

The analysis of the existing masonry wail revealed that the wall only provides a small percentage of the required resistance for the specified blast. Due to the symmetry of the wall and the reinforcement (for the upgrade system), the analysis for the rebound blast loads was not required. 

A typical shear connection for a wall girt might consist of a relatively thin two bolt shear tab. As a blast load is applied to the girt, tearout of the tab may occur due to an inadequate number of bolts or insufficient weld capacity. This will prevent development of plastic moment capacity of the member and thus reduce its blast resistance. A typical upgrade for this type of connection is addition of a new shear tab wetded or bolted to the existing column and girt. 

Headed studs are normally used to secure a roof slab to a structural steel framing system for rebound loads in new designs. This option may not available for upgrading existing structures. It may be necessary to provide through bolts to the structural frame with a backing plate on the top side of the stab. 

This chapter provides an example of the evaluation and retrofit of the masonry walls of an existing reinforced concrete framed building using the principles outlined in Chapter 10. The evaluation of the roof, structural framing and foundation are not covered in this example. The explosion magnitude and front wall blast load are determined by others. The analysis of the exterior walls, and upgrade options, arc presented in this example. 

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