INFLUENCE OF THE 2002 TEXAS SECTION OF ASCE RECOMMENDED PRACTICE ON THE BEAM DEPTHS FOR STIFFENED SLABS ON SHRINK-SWELL SOILS USING BRAB AND WRI

摘要

The most common foundation for light structures founded on shrink-swell soils is the stiffened slab on grade. The beam depth is an intrinsic design parameter for this type of foundation, it usually ranges between 0.6 and 1.2 m with common beam spacing of 3 to 6 m in both directions. The following methods are among the most common methods used to calculate the beam depth, spacing, and reinforcement needed for a safe and serviceable foundation: 1) BRAB Method (1968); 2) WRI Method (1980, 1996); 3) PTI Method (1996); 4) AS 2870 (1996); 5) PTI Method (2004). In 2002, the Texas section of ASCE provided recommended practice for the design of residential foundations that impacts the beam depth using WRI and BRAB. To examine the influence of this recommended practice in the resulting beam depths, 27 cases are designed. They include three simple rectangular stiffened slabs subjected to three different weather patterns, built on three different shrink-swell soils, and loaded with a uniform pressure and perimeter line load. The resulting beam depths using the WRI and BRAB methods with and without the recommendations of the Texas section of ASCE are presented and discussed for different soil and weather conditions. The PTI and Australian method are also presented for additional comparison purposes.