深中通道沉管隧道复合地基沉降特性研究
Study on settlement characteristics of composite foundation of Shenzhen-Zhongshan link immersed tube tunnel
贾绍明 1王啟铜 2宋神友 2金文良 2付佰勇 3陈卓杰4
作者信息
- 1. 广东省交通运输厅,广东 广州 510101
- 2. 深中通道管理中心,广东 广州 510600
- 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
- 4. 浙江大学 滨海和城市岩土工程研究中心,浙江 杭州 310058
- 折叠
摘要
深中通道是国内首次大规模使用水下深层水泥搅拌桩处理沉管隧道地基的超级工程,具有碎石垫层厚度大、深层水泥搅拌桩置换率高等特点,目前相关研究较少.为了研究厚垫层和高置换率深层水泥搅拌桩复合地基的沉降变形规律,在现场荷载板试验结果的基础上,将碎石垫层、复合地基和桩端全风化岩层视为一个共同作用的系统,假设在桩土分界面处桩土位移模式非同步,同一深度处桩间土体的位移模式非协调,考虑系统各部分在交界面上应力和变形连续,通过对典型单元体的分析,推导了复合地基桩土应力比和沉降的求解公式,最后将计算结果与现场荷载板试验结果和传统方法进行了对比验证.研究结果表明:本文方法计算所得沉降与实测沉降相比误差在 8.0%以内,计算精度优于传统方法,并且沉降随荷载的变化趋势大体相同,说明本文方法能较好反映沉管隧道复合地基的沉降特性;根据本文方法计算得到的桩土应力比与实测桩土应力比相比误差在-7.0%以内,可以认为理论计算的结果可靠.
Abstract
The Shenzhen-Zhongshan Link is the first super project in China to use underwater deep cement mixing pile to treat the foundation of immersed tunnel on a large scale,and it has the characteristics of large gravel cushion thickness and high replacement rate of deep cement mixing piles.At present,there are few relevant studies.In order to study the settlement deformation law of thick cushion and deep cement mixing pile composite foundation with high replacement rate,on the basis of the field load plate test results,the gravel cushion,composite foundation and completely weathered rock at the pile end were considered as a joint action system.Assuming that the displacement mode of pile and soil at the pile soil interface is not synchronous,and the displacement mode of soil between piles at the same depth is not coordinated,and considering that the stress and deformation of each part of the system are continuous at the interface,the formulas for calculating the pile-soil stress ratio and settlement of composite foundation were derivedthrough the analysis of typical elements.Finally,the results were compared with the field load plate test results andtraditional method.The results show that the error between the settlement calculated by this method and the measured settlement is less than 8%,the calculation accuracy is better than the traditional method,and the change trend of settlement with load is basically the same,indicating that the method in this paper can better reflect the settlement characteristics of composite foundation of immersed tube tunnel.The error between the pile-soil stress ratio calculated by this method and the measured pile-soil stress ratio is within-7%,which can be considered as reliable.
关键词
沉管隧道/复合地基/沉降计算/解析法/荷载传递Key words
immersed tube tunnel/composite foundation/settlement calculation/analytical method/load transfer引用本文复制引用
基金项目
广东省重点领域研发计划(2019B111105002)
出版年
2024
NETL
NSTL
万方数据