摘要
分析了目前规范确定承载力的方法,认为其不足之处是没有对应明确的安全系数和沉降变形值,实际应用中存在硬土或低压缩性地基的承载力偏保守,而软土或高压缩性地基以及大尺寸基础的承载力会因沉降变形过大而存在风险。建议地基的承载力应由岩土的强度参数和变形参数对具体的基础进行地基的强度和变形计算,按强度和变形双控的原则确定其最大地基承载力,可以获得地基承载力明确的安全系数和沉降值,获得更为科学合理的地基承载力,能更充分地利用地基的承载力进行地基设计,同时安全也更具有保障性,有较好的工程应用价值。建议现场压板载荷试验用于反算地基土的强度和变形参数,而不是用于直接确定承载力,现场压板试验没有进行到极限状态时建议用最大试验载荷值确定土的强度参数,土的变形参数则对试验曲线采用双曲线拟合确定。文中还建议了简易的双控确定方法,便于应用,通过案例对方法予以说明。
Reasonable determination of bearing capacity of foundation soils is a most important part of making full use of the bearing capacity of foundation soils. This paper analyzes the method suggested by the present code, and points out some shortcomings such as the corresponding relation between safety factor and settlement value is not clear and definite. In the practical application, the determination of the bearing capacity of stiff soil or low compressive foundation soils is usually conservative; while the soft soil, high compressive foundation soils and large-size foundation will at risks due to large settlement. Thus, a new solution method is proposed in this paper. That is, computing strength and deformation of a specific foundation by using strength and deformation parameters. Then, according to the double controlling method, the settlement requirement and strength safety factor requirement of the foundation soils, the bearing capacity of the foundation soils can be determined. Finally, by obtaining specific safety factor, settlement value and more reasonable bearing capacity of foundation, it is helpful to make better use of the bearing capacity of foundation soils in engineering design. At the same time, safety and engineering value are reached. When the in-situ plate loading test hasn't reached limit state, one suggestion on determining strength parameters is using maximum test value. The simple double controlling principle is also suggested in this paper. A case study is presented to make application easier. © 2016, Science Press. All right reserved.
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2016年第S2期232-242,共11页
Rock and Soil Mechanics
