刚性桩复合地基稳定性计算及其图解法  

Stability Charts and Calculation Method of Rigid Pile Composite Foundation

作　　者：聂文峰[1] 孙希望[1] 邱恩喜 李能[1] Nie Wenfeng;Sun Xiwang;Qiu Enxi;Li Neng(Kunming Survey,Design and Research Institute Co.,Ltd.,of CREEC,Kunming 650200,Yunnan,China;School of Civile Engineering and Geomatics,Southwest Petroleum Universtity,Chengdu 610500,China)

机构地区：[1]中铁二院昆明勘察设计研究院有限责任公司,云南昆明650200 [2]西南石油大学土木工程与测绘学院,成都610500

出　　处：《科技通报》2023年第8期69-75,共7页Bulletin of Science and Technology

基　　金：中铁二院昆明勘察设计研究院科研项目(KY2021072901);四川省科技厅项目(2020YJ0416);地质灾害防治与地质环境保护国家重点实验室开放基金资助项目(SKLGP2021K017);岩土力学与工程国家重点实验室开放基金资助项目(SKLGME021014)。

摘　　要：刚性桩复合地基支承路堤的稳定性评价是近年来研究的热点和难点问题。本文首先从刚性桩复合地基的承载特性出发,仅考虑其竖向支承作用对路堤的稳定性贡献,通过计算桩和桩间土的荷载分担比,进而基于路堤折减荷载原理将刚性桩复合地基支承路堤的稳定性问题转化为折减路堤荷载下天然地基的稳定性问题;其次,将折减荷载后的路堤边坡视为双层土质边坡,以极限分析上限定理为框架,推导双层土质路堤边坡两段对数螺旋线滑面破坏机制下的外力功率及内部耗散功率的解析表达式,结合最优化方法与强度折减技术,藉此提出了基于折减荷载原理的刚性桩复合地基支撑路堤稳定性的快速计算方法,并基于某一具体算例将其与其他方法进行对比,验证该方法的合理性;最后,提出一种适用于路堤稳定性分析的图解法,并依托不同路堤填土工况介绍了该图解法的使用步骤与方法。研究成果为刚性桩支承路堤的稳定性计算提供了一种新的思路和理论支撑。The stability calculation of the embankment supported by rigid pile composite foundation is a hot and difficult problem in recent years.Firstly,starting from the bearing characteristics of rigid pile composite foundation,the stability of the embankment supported by the rigid pile composite foundation is transformed into the stability of the natural foundation under the reduced embankment load by calculating the load sharing ratio between the piles and the soil.Secondly,the embankment slope can be regarded as a two-layered soil slope.Using the upper limit theorem of limit analysis as a framework,the analytical expressions for the external force power and internal dissipation power of the two-segmented soil embankment slope under the rotational failure mechanism are derived,and the optimization method and the strength reduction technique are combined to propose a rapid calculation method for the stability of embankment supported by rigid pile based on the principle of load reduction.And the method is compared with other methods based on a specific example to verify its validity.Finally,stability charts for embankment is proposed,and the steps of the method of stability charts are introduced based on different conditions.The research results provide a new idea and theoretical support for the stability calculation of rigid pile-supported embankments.

关 键 词：刚性桩复合地基 稳定性 折减荷载 上限定理 图解法 

分 类 号：TU432[建筑科学—岩土工程]