【摘要】 针对基坑支护结构设计深度的这一基坑设计中争议较大的问题,以土钉支护结构为研究对象,运用有限元强度折减方法,研究了基坑工程中最为常见的基础梁、桩基承台局部超深开挖的设计深度问题。研究表明:强度折减的有限元方法完全能应用于边坡及土钉支护结构的极限设计中;为真正做到土钉支护结构设计的合理、安全、可靠,应根据不同的局部超深开挖的深度、尺寸及距离分别考虑;可不考虑基础梁的局部超深开挖,或1～3桩承台可考虑1/2的超深深度,或多桩承台应计算至超深开挖深度的基底。更多还原

【Abstract】 The design depth problem of excavation protection structures is one of controversial issues in the design of foundation pits.Taking the soil-nailing structure for the study,the strength reduction FEM is employed to solve this problem.The design depth of local ultra-deep excavation such as base beams and pile caps in the excavation is studied.Research shows that: the strength reduction FEM can be applied to the limit design of slopes and soil-nailing structures;different local ultra-deep excavation depths,sizes and distances are respectively treated in order that the soil nailing structures are truly designed reasonably,safely and reliably.In the design,the base beam ultra-deep excavation can not be considered,1/2 of the ultra-deep excavation depth can be considered for the caps with 1～3 piles,and the ultra-deep excavation depth should be considered for the caps with many piles.更多还原