可控刚度桩筏基础变刚度调平的工程实践
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摘要
基底下的地基土支承刚度不均匀导致的建筑基础差异沉降问题在中软土及土岩溶组合地区较为突出,因此,减少其差异沉降是高层建筑桩筏基础设计中的关键点。本文介绍的典型工程采用以天然地基为主、部分区域内采用桩顶设置刚度调节装置的人工挖孔桩的变刚度调平设计方法,在解决因地基土差异沉降过大引起的差异沉降问题的同时,还充分利用了良好的天然地基承载力,取得了良好的经济效益和社会效益。通过现场测试数据与结果进行对比分析,验证可控刚度桩筏基础应用于该项目的合理性与可靠性。现场实测结果显示,本工程D区域采用可控刚度桩筏基础后,建筑物总沉降和差异沉降均满足设计要求,地基土分担了上部结构65%的荷载,充分发挥了地基土体承载力。设计思路及相关经验可供类似工程借鉴与参考。
The uneven foundation settlement due to the uneven soil stiffness under the base in the soft soil and karst area is obvious,Therefore,reducing the differential settlement is the key point in the design of piled raft foundation of high-rise building. The typical engineering introduced in this paper adopts the variable stiffness method which is mainly based on natural foundation with manual digging pile equipped with deformation adjustors in partial area. The problem of differential settlement caused by uneven soil foundation stiffness is solved. It also makes full use of the good bearing capacity of the natural foundation,and good economic and social benefits are achieved. Through comparing and analyzing the field test data and results,the rationality and reliability of the application of the controllable rigidity pile raft foundation to the project are verified. Field measurement results show that,in this project,the total settlement and differential settlement of the building meet the design requirements when manual digging pile with deformation adjustors are used in the D area. And the ground soil shares sixty-five percent of the load of the superstructure,which means it gives full play to the bearing capacity of foundation soil.The design idea and relevant experience can be used for the similar projects.
The uneven foundation settlement due to the uneven soil stiffness under the base in the soft soil and karst area is obvious,Therefore,reducing the differential settlement is the key point in the design of piled raft foundation of high-rise building. The typical engineering introduced in this paper adopts the variable stiffness method which is mainly based on natural foundation with manual digging pile equipped with deformation adjustors in partial area. The problem of differential settlement caused by uneven soil foundation stiffness is solved. It also makes full use of the good bearing capacity of the natural foundation,and good economic and social benefits are achieved. Through comparing and analyzing the field test data and results,the rationality and reliability of the application of the controllable rigidity pile raft foundation to the project are verified. Field measurement results show that,in this project,the total settlement and differential settlement of the building meet the design requirements when manual digging pile with deformation adjustors are used in the D area. And the ground soil shares sixty-five percent of the load of the superstructure,which means it gives full play to the bearing capacity of foundation soil.The design idea and relevant experience can be used for the similar projects.
引文
[1]宰金珉.复合桩基理论与应用[M].北京:知识产权出版社,2004:198-214.Zai Jinmin.Theory and practice of composite pile foundation[M].Beijing:Intellectual Property Publishing House,2004:198-214(in Chinese)
[2]刘金砺,迟铃泉.桩土变形计算模型和变刚度调平设计[J].岩土工程学报,2000,(2):151-157Liu Jinli,Chi Linquan.The modified model of pile-soil deformation calculation and variable rigidity design method for balance settlement[J].Chinese Journal of Geotechnical Engineering,2000,(2):151-157(in Chinese)
[3]王涛.变刚度调平布桩模式下筏底地基土承载性状研究[J].岩土工程学报,2011,(7):1014-1021Wang Tao.Bearing capacity of piles in optimized design of pile foundation stiffness to reduce differential settlement[J].Chinese Journal of Geotechnical Engineering,2011,(7):1014-1021(in Chinese)
[4]Kim K N,Lee S H,Kim K S,et al.Optimal pile arrangement for minimizing differential settlements in piled raft foundation[J].Computers and Geosciences,2001,28(4):235-253
[5]宰金珉,周峰,梅国雄,等.自适应调节下广义复合基础设计方法与工程实践[J].岩土工程学报,2008,(1):93-99Zai Jinmin,Zhou Feng,Mei Guoxiong,et al.Design method and practice of generalized composite foundation by use of adaptive adjustor[J].Chinese Journal of Geotechnical Engineering,2008,30(1):93-99(in Chinese)
[6]刘金砺.高层建筑地基基础概念设计的思考[J].土木工程学报,2006,(6):100-105Liu Jinli.Review and optimization of the conceptual design of foundations for high-rise buildings[J].China Civil Engineering Journal,2006,(6):100-105(in Chinese)
[7]王涛,高文生,刘金砺.桩基变刚度调平设计的实施方法研究[J].岩土工程学报,2010,(4):531-537Wang Tao,Gao Wensheng,Liu Jinli.Study on implemention method for optimization design of pile foundation stiffness to reduce differential settlement[J].Chinese Journal of Geotechnical Engineering,2010,(4):531-537(in Chinese)
[8]张武,高文生.变刚度布桩复合地基模型试验研究[J].岩土工程学报,2009,(6):905-910Zhang Wu,Gao Wensheng.Experimental study on composite piled raft foundation[J].Chinese Journal of Geotechnical Engineering,2009,(6):905-910(in Chinese)
[9]陈龙珠,梁发云,丁屹.变刚度复合地基处理的有限元分析[J].工业建筑,2003,(11):1-4Chen Longzhu,Liang Fayun,Ding Yi.Analysis of compound foundation of variable rigidity with FEM[J].Industrial Construction,2003,(11):1-4(in Chinese)
[10]周峰,宰金珉,梅国雄,等.天然地基变刚度垫层的概念与方法[J].四川建筑科学研究,2009,(4):116-119Zhou Feng,Zai Jinmin,Mei Guoxiong,Liu Songyu.Concept and method of variable rigidity bedding for subgrad[J].Sichuan Building Scienc,2009,(4):116-119(in Chinese)
[11]宰金珉.地基刚度的人为调整及其工程应用[A].中国土木工程学会第八届土力学及岩土工程学术会议论文集[C].1999:235-238Zai Jinmin.Artificial adjustment of foundation stiffness and its engineering application[A].Proceedings of the Eighth Symposium on Soil Mechanics and Geotechnical Engineering of the Chinese Society of Civil Engineering[C].1999:235-238(in Chinese)
[12]宰金珉,周峰,梅国雄,等.端承桩复合桩基及其设计方法[J].工业建筑,2008,(1):60-64Zai Jinmin,Zhou Feng,Mei Guoxiong,et al.End-bearing composite pile foundation and its design method[J].Industrial Construction,2008,(1):60-64(in Chinese)
[13]周峰,朱锐,郭天祥,等.可控刚度桩筏基础桩土共同作用的工程实践[J].岩石力学与工程学报,2017,36(12):3075-3084Zhou Feng,Zhu Rui,Guo Tianxiang,et al.Engineering practice in pile-soil interaction of pile-raft foundations with controllable stiffness[J].Journal of Rock Mechanics and Geotechnical Engineering,2017,36(12):3075-3084(in Chinese)
[14]Zhou F,Lin C,Wang X,et al.Application of deformation adjustors in piled raft foundations[A].Proceedings of the Institution of Civil Engineers-Geotechnical Engineering[C].2016
[15]GB 50007—2011,建筑地基基础设计规范[S]GB 50007—2011,Code for design of buiding foundation[S](in Chinese)
[16]JGJ 94—2008,建筑桩基技术规范[S]JGJ 94-2008,Technical code for building pile foundations[S](in Chinese)
[17]JGJ 72—2004,高层建筑岩土工程勘察规程[S]JGJ 72—2004,Specification for geotechnical investigation of tall buildings[S](in Chinese)
[2]刘金砺,迟铃泉.桩土变形计算模型和变刚度调平设计[J].岩土工程学报,2000,(2):151-157Liu Jinli,Chi Linquan.The modified model of pile-soil deformation calculation and variable rigidity design method for balance settlement[J].Chinese Journal of Geotechnical Engineering,2000,(2):151-157(in Chinese)
[3]王涛.变刚度调平布桩模式下筏底地基土承载性状研究[J].岩土工程学报,2011,(7):1014-1021Wang Tao.Bearing capacity of piles in optimized design of pile foundation stiffness to reduce differential settlement[J].Chinese Journal of Geotechnical Engineering,2011,(7):1014-1021(in Chinese)
[4]Kim K N,Lee S H,Kim K S,et al.Optimal pile arrangement for minimizing differential settlements in piled raft foundation[J].Computers and Geosciences,2001,28(4):235-253
[5]宰金珉,周峰,梅国雄,等.自适应调节下广义复合基础设计方法与工程实践[J].岩土工程学报,2008,(1):93-99Zai Jinmin,Zhou Feng,Mei Guoxiong,et al.Design method and practice of generalized composite foundation by use of adaptive adjustor[J].Chinese Journal of Geotechnical Engineering,2008,30(1):93-99(in Chinese)
[6]刘金砺.高层建筑地基基础概念设计的思考[J].土木工程学报,2006,(6):100-105Liu Jinli.Review and optimization of the conceptual design of foundations for high-rise buildings[J].China Civil Engineering Journal,2006,(6):100-105(in Chinese)
[7]王涛,高文生,刘金砺.桩基变刚度调平设计的实施方法研究[J].岩土工程学报,2010,(4):531-537Wang Tao,Gao Wensheng,Liu Jinli.Study on implemention method for optimization design of pile foundation stiffness to reduce differential settlement[J].Chinese Journal of Geotechnical Engineering,2010,(4):531-537(in Chinese)
[8]张武,高文生.变刚度布桩复合地基模型试验研究[J].岩土工程学报,2009,(6):905-910Zhang Wu,Gao Wensheng.Experimental study on composite piled raft foundation[J].Chinese Journal of Geotechnical Engineering,2009,(6):905-910(in Chinese)
[9]陈龙珠,梁发云,丁屹.变刚度复合地基处理的有限元分析[J].工业建筑,2003,(11):1-4Chen Longzhu,Liang Fayun,Ding Yi.Analysis of compound foundation of variable rigidity with FEM[J].Industrial Construction,2003,(11):1-4(in Chinese)
[10]周峰,宰金珉,梅国雄,等.天然地基变刚度垫层的概念与方法[J].四川建筑科学研究,2009,(4):116-119Zhou Feng,Zai Jinmin,Mei Guoxiong,Liu Songyu.Concept and method of variable rigidity bedding for subgrad[J].Sichuan Building Scienc,2009,(4):116-119(in Chinese)
[11]宰金珉.地基刚度的人为调整及其工程应用[A].中国土木工程学会第八届土力学及岩土工程学术会议论文集[C].1999:235-238Zai Jinmin.Artificial adjustment of foundation stiffness and its engineering application[A].Proceedings of the Eighth Symposium on Soil Mechanics and Geotechnical Engineering of the Chinese Society of Civil Engineering[C].1999:235-238(in Chinese)
[12]宰金珉,周峰,梅国雄,等.端承桩复合桩基及其设计方法[J].工业建筑,2008,(1):60-64Zai Jinmin,Zhou Feng,Mei Guoxiong,et al.End-bearing composite pile foundation and its design method[J].Industrial Construction,2008,(1):60-64(in Chinese)
[13]周峰,朱锐,郭天祥,等.可控刚度桩筏基础桩土共同作用的工程实践[J].岩石力学与工程学报,2017,36(12):3075-3084Zhou Feng,Zhu Rui,Guo Tianxiang,et al.Engineering practice in pile-soil interaction of pile-raft foundations with controllable stiffness[J].Journal of Rock Mechanics and Geotechnical Engineering,2017,36(12):3075-3084(in Chinese)
[14]Zhou F,Lin C,Wang X,et al.Application of deformation adjustors in piled raft foundations[A].Proceedings of the Institution of Civil Engineers-Geotechnical Engineering[C].2016
[15]GB 50007—2011,建筑地基基础设计规范[S]GB 50007—2011,Code for design of buiding foundation[S](in Chinese)
[16]JGJ 94—2008,建筑桩基技术规范[S]JGJ 94-2008,Technical code for building pile foundations[S](in Chinese)
[17]JGJ 72—2004,高层建筑岩土工程勘察规程[S]JGJ 72—2004,Specification for geotechnical investigation of tall buildings[S](in Chinese)