地连墙-重力式复合锚碇基础承载性能试验研究  

Experimental study of bearing capacity of underground diaphragm wall-gravity anchorage composite foundation

作　　者：罗林阁 崔立川[2] 石海洋 过超 易绍平[2] LUO Lin-ge;CUI Li-chuan;SHI Hai-yang;GUO Chao;YI Shao-ping(Qingyun Highway Management Center of Guangdong Nanyue Transportation Investment & Construction Co.,Ltd.,Guangzhou,Guangdong 510199,China;China Communication Highway Planning and Design Institute,Beijing 100088,China;CCCC Highway Bridges National Engineering Research Centre Co.,Ltd.,Beijing 100088,China)

机构地区：[1]广东南粤交投清云高速管理中心,广东广州510199 [2]中交公路规划设计院有限公司,北京100088 [3]中交公路长大桥建设国家工程研究中心有限公司,北京100088

出　　处：《岩土力学》2019年第3期1049-1058,共10页Rock and Soil Mechanics

基　　金：国家重点研发计划专项资助(No.2018YFC0809600);贵州省科技计划项目资助(No.[2016]2013)~~

摘　　要：为研究地连墙-重力式复合锚碇基础底板以下地连墙嵌固作用对其承载性能的影响,依托西江特大桥清远侧新型地连墙锚碇设计方案,分别开展相同试验条件下地连墙-重力式复合锚碇基础与不考虑地连墙嵌固效应的常规锚碇基础两组物理模型试验,对荷载与位移关系、基底土压力分布及荷载分配规律进行分析。结果表明:与常规锚碇相比,由于地连墙嵌入深部中分化基岩,地连墙-重力式复合锚碇基础可充分发挥嵌岩地连墙强度及深层岩体承载能力,在竖向荷载和水平荷载作用下,地连墙-重力式复合锚碇基础竖向位移和水平位移均明显小于无嵌岩地连墙的常规锚碇基础,其中设计缆力条件下可降低水平位移量75%左右,表明嵌岩地连墙结构有效提高了锚碇基础承载性能和安全储备。由土压力及荷载分配规律可知,上部竖向荷载通过地连墙结构传递到深部基岩,有效分担了基础底板土体压应力,进而降低地基土体附加应力和基础沉降量。综合表明,当地连墙结构嵌入深部强度较好的基岩时,采用地连墙作为基坑围护结构的锚碇基础设计可考虑地连墙嵌固作用对其承载力的贡献。To study the influence of the embedding action of diaphragm wall below the bottom of diaphragm wall-gravity anchorage composite foundation on its bearing capacity, two sets of physical model tests of the underground diaphragm wall-anchor combined foundation and the conventional anchor foundation without considering the embedding effect of diaphragm wall-were carried out under the same conditions, relying on the design scheme of new diaphragm wall anchorage at Qingyuan side of Xijiang Super Bridge.The relationship between load and displacement, the distribution of soil pressure and the load distribution are analyzed. The results show that the vertical displacement and horizontal displacement of the combined anchor foundation are obviously smaller than that of the conventional anchor foundation due to the consolidation and fixed effect of the diaphragm wall under the vertical and horizontal loads. Compared with the conventional anchorage, diaphragm wall-gravity type composite anchorage foundation can make full use of diaphragm strength embedded into rock and bearing capacity of deep rock mass. The horizontal displacement can be reduced by about 75% under the design of cable force, which effectively improve the bearing and safety performance. The vertical load can transfer from the ground wall structure to the deep bedrock, which can share the soil pressure on the foundation base, and reduce additional stress and settlement, according to the soil pressure and load distribution law. The comprehensive analysis shows that the contribution for bearing capacity of ground diaphragm wall designed as the anchorage foundation of the retaining structure can be considered in design, when the bottom of underground diaphragm wall is embedded into bedrock.

关 键 词：地连墙-重力式复合锚碇 模型试验 嵌固作用 荷载分配 

分 类 号：TU476.3[建筑科学—结构工程]