地铁车站软土地基变形计算及处理方法
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摘要
为掌握不同厚度软土地基车站加固前的变形特性,为软土地基加固提供理论支撑,利用回弹再压缩方法对基底变形进行了精确计算,并对桩基+牛腿+三轴搅拌桩抽条、桩基+三轴搅拌桩抽条、三轴搅拌桩裙边+抽条以及桩基+三轴搅拌桩裙边+抽条等4个加固方案进行了技术经济对比。分析结果表明,当基底以下存在软土时,按回弹再压缩方法计算的变形约为基底软土厚度的0.015倍,需加固至较好地层;基底加固亦可有效减小基坑开挖变形及内力;综合考虑造价及加固效果,采用桩基+牛腿+三轴搅拌桩抽条方案较优。此方案已在佛山地铁3号线大墩站一期工程中成功应用。
In order to master the deformation characteristics of different soft foundation stations before reinforcement, so as provide a theoretical support for soft foundation reinforcement, the rebound recompression method is used to accurately calculate the base deformation, at the same time, four reinforcement schemes are compared from technical and economic perspectives, including pile foundation + bracket + three-axis mixing pile pumping, pile foundation + three-axis mixing pile pumping, three-axis mixing pile +sprout and pile foundation + three-axis mixing pile skirt + sprout. The analysis results show that when the soft soil is under the basement, the deformation calculated by the rebound recompression method is about 0.015 times the thickness of the soft soil, then the soil needs to be strengthened to a better formation, because the base reinforcement can effectively reduce the excavation deformation and internal force of the foundation pit. Based on a comprehensive consideration of the cost and reinforcement effect, the scheme of pile foundation + bracket + three-axis mixing pile is recommended, which has been successfully applied in the first phase of Dadun Station project on metro Line 3 in Foshan City.
In order to master the deformation characteristics of different soft foundation stations before reinforcement, so as provide a theoretical support for soft foundation reinforcement, the rebound recompression method is used to accurately calculate the base deformation, at the same time, four reinforcement schemes are compared from technical and economic perspectives, including pile foundation + bracket + three-axis mixing pile pumping, pile foundation + three-axis mixing pile pumping, three-axis mixing pile +sprout and pile foundation + three-axis mixing pile skirt + sprout. The analysis results show that when the soft soil is under the basement, the deformation calculated by the rebound recompression method is about 0.015 times the thickness of the soft soil, then the soil needs to be strengthened to a better formation, because the base reinforcement can effectively reduce the excavation deformation and internal force of the foundation pit. Based on a comprehensive consideration of the cost and reinforcement effect, the scheme of pile foundation + bracket + three-axis mixing pile is recommended, which has been successfully applied in the first phase of Dadun Station project on metro Line 3 in Foshan City.
引文
[1] 王鹏.地铁车辆段软土地基沉降控制方法研究[D].广州:华南理工大学,2017.
[2] 宋绪国,隋孝民.深圳地铁南头车辆段软基处理设计[J].铁道标准设计,2006(4):24.
[3] 许军,张开顺.软弱砂层下的地铁隧道穿越建筑物的加固技术及注浆控制效果分析[J].城市轨道交通研究,2017(5):122.
[4] 龚彦峰,王爱武,周坤,等.软土盾构隧道基底加固对长期沉降的影响分析[J].重庆交通大学学报(自然科学版),2017(10):19.
[5] 李彦涛,范欣荣,高岗荣,等.地铁联络通道软基加固施工与监测[J].煤炭科学技术,2001(10):20.
[6] 张涛.浅谈西安地铁施工软基处理施工技术应用[J].科技创新导报,2017,14(24):77.
[7] 朱志祥,刘少炜,刘新荣,等.某地铁车站软土深基坑加固效果研究[J].地下空间与工程学报,2014,10(3):716.
[8] 刘雪珠,张艳书,顾蒙娜,等.坑底加固置换率对杭州地铁湘湖站深基坑安全的影响分析[J].岩土工程学报,2016,38(增刊2):136.
[9] 李卓峰,林伟岸,朱瑶宏,等.坑底加固控制地铁基坑开挖引起土体位移的现场测试与分析[J].浙江大学学报(工学版),2017,51(8):1475.
[10] 汪清河.地铁车站软土深基坑水泥搅拌桩加固施工技术[J].工程与建设,2015,29(3):396.
[11] 汤翔宇,仇志斌.邻近拟建地铁深基坑的现有基坑加固与改造设计[J].建筑结构,2013,43(增刊1):898.
[12] 游思琴,陈启军,董如意,等.佛山市城市轨道交通3号线工程大墩站详细勘察阶段岩土工程勘察报告(第一版)[R].佛山:中水珠江规划勘测设计有限公司,2016.
[13] 中华人民共和国住房和城乡建设部.建筑地基基础设计规范:GB 50007—2011[S].北京:中国建筑工业出版社,2011:22-23,137-139.
[14] 周秋娟.不同卸荷路径下软土变形特性试验研究[J].工程勘察,2013,41(10):17.
[15] 中华人民共和国住房和城乡建设部.城市轨道交通结构安全保护技术规范:CJJ/T 202—2013[S].北京:中国建筑工业出版社,2013:24.
[2] 宋绪国,隋孝民.深圳地铁南头车辆段软基处理设计[J].铁道标准设计,2006(4):24.
[3] 许军,张开顺.软弱砂层下的地铁隧道穿越建筑物的加固技术及注浆控制效果分析[J].城市轨道交通研究,2017(5):122.
[4] 龚彦峰,王爱武,周坤,等.软土盾构隧道基底加固对长期沉降的影响分析[J].重庆交通大学学报(自然科学版),2017(10):19.
[5] 李彦涛,范欣荣,高岗荣,等.地铁联络通道软基加固施工与监测[J].煤炭科学技术,2001(10):20.
[6] 张涛.浅谈西安地铁施工软基处理施工技术应用[J].科技创新导报,2017,14(24):77.
[7] 朱志祥,刘少炜,刘新荣,等.某地铁车站软土深基坑加固效果研究[J].地下空间与工程学报,2014,10(3):716.
[8] 刘雪珠,张艳书,顾蒙娜,等.坑底加固置换率对杭州地铁湘湖站深基坑安全的影响分析[J].岩土工程学报,2016,38(增刊2):136.
[9] 李卓峰,林伟岸,朱瑶宏,等.坑底加固控制地铁基坑开挖引起土体位移的现场测试与分析[J].浙江大学学报(工学版),2017,51(8):1475.
[10] 汪清河.地铁车站软土深基坑水泥搅拌桩加固施工技术[J].工程与建设,2015,29(3):396.
[11] 汤翔宇,仇志斌.邻近拟建地铁深基坑的现有基坑加固与改造设计[J].建筑结构,2013,43(增刊1):898.
[12] 游思琴,陈启军,董如意,等.佛山市城市轨道交通3号线工程大墩站详细勘察阶段岩土工程勘察报告(第一版)[R].佛山:中水珠江规划勘测设计有限公司,2016.
[13] 中华人民共和国住房和城乡建设部.建筑地基基础设计规范:GB 50007—2011[S].北京:中国建筑工业出版社,2011:22-23,137-139.
[14] 周秋娟.不同卸荷路径下软土变形特性试验研究[J].工程勘察,2013,41(10):17.
[15] 中华人民共和国住房和城乡建设部.城市轨道交通结构安全保护技术规范:CJJ/T 202—2013[S].北京:中国建筑工业出版社,2013:24.