【作者】 李晖；

【导师】 骆汉宾；

【作者基本信息】 华中科技大学 ， 建筑与土木工程， 2011， 硕士

【摘要】 随着深基坑工程的增多,隔离桩被广泛应用于深基坑围护结构中,用以隔离土压力的传递,减少基坑施工过程中对周边建筑物的影响。但在实际工程中,往往只注意到隔离桩对土体侧向压力的隔离,忽视了隔离桩施工过程中对土体的扰动,以及引起的周边建筑物沉降和后续施工影响。因此,工程施工中需要量化隔离桩施工对周边土体的扰动影响程度。本文首先对隔离桩施工引起土体扰动的机理进行阐述,介绍当前几种桩施工引起土体扰动的预估理论和计算方法;接着,从桩入土深度和土的性质等角度探讨隔离桩施工中引起土体扰动程度的影响因素,选取武汉轨道交通二号线一期工程循礼门站和武汉轻轨为研究对象,结合经验法和圆孔扩张理论,分析隔离桩施工引起轻轨桥墩沉降的影响因素;在此基础上,对隔离桩施工引起轻轨桥墩沉降的监测数据进行分析;最后,结合监测数据,通过有限元数值计算,模拟扰动过程,并对影响因素进行敏感性分析,论证特殊情况下基坑施工设置隔离桩合理性,并根据隔离桩施工的扰动影响提出相应的解决措施,降低因隔离桩施工所带来安全风险机率,确保项目的正常运行。本文总结了减少隔离桩施工对土体扰动的控制方法,具有较强的实用性,为隔离桩的设计和施工控制提供参考。更多还原

【Abstract】 Following the increase of deep excavation engineering, partition piles were widely applied to the building envelope of deep foundation pit, to isolate the soil pressure and to reduce the influence of foundation pit to surrounding buildings in the process of construction. In practical projects, however, attention is only payed to segregating the lateral pressure of soil from partition piles, ignoring the influence of partition piles during construction process to the disturbance of soil which causes the displacement of surrounding buildings and the subsequent effects of constuction. Under such circumstances, project construction should be quantified the degree of disturbing influence of the partition piles to the peripheral soil in construction process.Firstly, this thesis elaborates the mechanics of soil disturbance caused by partition piles in the process of construction, introducing several estimation theories and computational methods with regard to this problem currently. Then, the thesis explores the influencing factors of soil disturbing degree caused by partition piles in the process of construction from the angles of the depth of piles in soil and the properties of soil. Wuhan light rail and XunLiMen station of the first-stage project of the line two of Wuhan rail transpotation have been selected as research objects. With the combination of empirical method and expansion theory of cylinder pore, the influencing factors of the settlement of bridges and light rails triggered by partition piles in construction process are analyzed in full explanation. On this basis, the monitoring data of the settlement of bridges and light rails triggered by partition piles in construction process is analyzed. Lastly, the thesis set up a simulation model accordingly by combining the monitoring data as well as through the calculation of finite elements numbers. Additionally, the thesis also conducts the sensitivity analysis to influencing factors and demonstrates the rationality of setting partition piles in foundation pits in constuction process in special situations. According to the disturbance effects of partition piles in construction, a set of solutions are put forward to decrease safety and risk probability so as to ensure normal operation of the project.The thesis has summarized the control method to reduce the degree of disturbance of soil impacted by partition piles under construction. The work I’ve done is of practicability which could offer reference to the design of partition piles and to the control of construction.更多还原