摘要
DCM联合碎石基床是处理跨海沉管隧道复杂地质条件的新型地基形式,在软土地区极具优势。依托深中通道沉管隧道工程,通过离心模型试验,研究了DCM联合碎石基床的承载特性和激振荷载对DCM桩身完整性的影响,研究结果表明:复合地基荷载-沉降曲线存在拐点,拐点前荷载和沉降呈线性关系,拐点后呈陡降型;碎石基床能够有效分散应力,提高地基的整体承载力;复合地基的极限承载力约是沉管底部最大荷载的1.5倍;当上部荷载超过地基极限承载力后,碎石会刺入DCM桩体内,引起桩头破碎,影响范围约为桩头以下3 m内;地基表面沉降较小,工后沉降占总沉降的15.5%,该新型地基形式能够有效控制沉降。
The combination of DCM and gravel foundation is a new type of foundation form for dealing with complex geological conditions of cross sea immersed tube tunnels,which has extremely advantageous in soft soil areas.Based on the immersed tunnel project of Shenzhong-Zhongshan Bridge,centrifugal model tests are conducted to study the bearing characteristics of the DCM combined gravel foundation and the influences of excitation loads on the integrity of the DCM piles.The research results show that there is a turning point in the load-settlement curve of the composite foundation and a linear relationship between the load and the settlement before the turning point,and a steep drop after the turning point.The gravel foundation can effectively disperse stress and improve the overall bearing capacity of the foundation.The ultimate bearing capacity of the composite foundation is about 1.5 times the maximum load at the bottom of the immersed tube.When the upper load exceeds the ultimate bearing capacity of the foundation,the gravel will penetrate into the DCM piles,causing the pile head to break,with an impact range of about 3 m below the pile head.The surface settlement of the foundation is relatively small,and the post-construction settlement accounts for 15.5% of the total settlement.This new type of foundation form can effectively control settlement.
作者
王雪奎
岳长喜
黄思杰
WANG Xuekui;YUE Changxi;HUANG Sijie(Tianjin Port Engineering Institute Co.,Ltd.of CCCC First Harbor Engineering Co.,Ltd,Tianjin 300461,China;Key Laboratory of Port Geotechnical Engineering,Ministry of Transport,PRC,Tianjin 300461,China;Key Laboratory of Port Geotechnical Engineering of Tianjin,Tianjin 300461,China;Key Laboratory of Geotechnical Engineering,CCCC,Tianjin 300222,China;CCCC First Habor Engineering Co.,Ltd.,Tianjin 300461,China;China Design Testing Technology CO.,LTD,Nanjing 210000,China)
出处
《岩土工程学报》
EI
CAS
CSCD
北大核心
2024年第S01期143-146,共4页
Chinese Journal of Geotechnical Engineering
关键词
DCM
复合地基
碎石基床
承载特性
DCM
composite foundation
gravel foundationt
bearing characteristic
