基坑开挖反压土截面特性对基坑性状影响的有限元分析  

Finite Element Analysis of Earth Berm Wxcavation Pit Traits Affect Section Properties

作　　者：刘畅[1] 孙盼盼[1] 赵露伟 李文杰[1] 

机构地区：[1]天津大学建筑工程学院,天津300072

出　　处：《地下空间与工程学报》2017年第3期788-795,共8页Chinese Journal of Underground Space and Engineering

基　　金：国家重点基础研究发展计划(973计划)(2010CB732106);天津市科技计划项目(11ZCGYSF00800)

摘　　要：根据反压土和支护结构的相互作用机理,采用有限元计算分析了反压土宽度、高度、坡度、放坡级数、面积等截面特征对支护结构位移和内力的影响规律。计算表明,随着反压土宽度、高度、坡度的增长,围护结构内力和位移也随之减小,但当这些截面特性发展到一定值时,其内力和位移减小趋势也逐渐趋于稳定。反压土面积是决定围护结构受力和位移的决定因素,当反压土面积相同时,开挖完成后的围护结构内力和位移基本相同,但随着工后时间的增长,宽高比决定围护结构位移和弯矩变化率的发展趋势。通过对具体的工程实例的分析结果表明,当反压土面积相同时,放坡级数不会影响反压土的受力和位移,合理的放坡级数应根据现场施工难易程度选择。According to the interaction mechanism of earth berm and supporting structures, the influences of earth berm width, height, slope, slope steps, area and other cross-sectional characteristics are calculated and analyzed on the supporting structure displacements and the supporting structure internal forces with the method of finite element analysis. The calculation resuhs show that as the growth of the earth berm width, height and slope, envelope forces and displacements of the supporting structure increases, but the development of these section properties to a certain value, the growth trend of the interned forces and displacements of the supporting structure has gradually stabilized. Earth berm area is a determining factor of the forces and displacements of the supporting structure, when the earth berm area is the same, retaining structure forces and displacements are basically the same after the completion of excavation, but with the growth of time after construction, the aspect ratio determines the development trends of change rate of the envelope displacement and bending moment. Through the analysis of specific project example, the result shows that when earth berm area is the same, slope steps does not affect the force and displacement of earth berm, reasonable slope steps should be chosen based on the degree of difficulty of the construction site.

关 键 词：反压土 有限元 土坡形状 宽高比 时间效应 

分 类 号：TU47[建筑科学—结构工程]