360R-06 Design of Slabs-on-Ground
DESIGN OF SLABS-ON-GROUND
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| DESIGN OF SLABS-ON-GROUND
360R-7 CHAPTER 3—SOIL SUPPORT SYSTEMS FOR SLABS-ON-GROUND 3.1—Introduction The design of slabs-on-ground to resist moments and shears caused by applied loads depends on the interaction between the concrete slab and the supporting materials. The properties and dimensions of the slab and the supporting materials are important in the design of a slab-on-ground. The support system should be of acceptable uniform capacity and not easily susceptible to be affected by climatic changes. Slab-on-ground failures can occur because a proper support system was not achieved. This chapter addresses issues related to the support system of the slab-on-ground, including: • Geotechnical engineering reports; • Subgrade classification; • Modulus of subgrade reaction; • Design of the slab support system; • Site preparation; and • Inspection and testing of the slab support system. This chapter is limited to those aspects of the support system necessary for the slab-on-ground to perform as intended. The slab support system consists of a subgrade, usually a base, and sometimes a subbase, as illustrated in Fig. 3.1. Crushed rock, gravels, or coarse sands, which have high strength, low compressibility, and high permeability, are commonly used as base courses. Crushed rock, gravels, sands, select soils, and stabilized soils are commonly used as subbases; however, they may also be used as base materials. Soils in the subgrade are generally the ultimate supporting materials, but bedrock, competent or weathered, may also be encountered. If the existing soil has uniform strength and other necessary properties to support the slab, the slab may be placed directly on the existing subgrade. The existing grade, however, is frequently not at the desired elevation or slope and, as such, some cut and fill is required. To improve surface drainage or to elevate the floor level, controlled fill using on-site or imported soils is required on some sites. tải về 2.35 Mb. Chia sẻ với bạn bè của bạn:
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