双排桩支护结构的计算理论研究及数值模拟

发布时间：2018-06-01 03:19

本文选题：基坑支护 + 双排桩　；参考：《昆明理工大学》2013年硕士论文

【摘要】：双排桩支护结构作为一种较为新型的支护方式,在控制基坑侧移、方便施工、节省地下空间等方面具有良好的效果,受到广大工程人士的青睐。但是从双排桩的实际应用情况来看,由于支护结构本身受力较为复杂,现有的设计计算理论还有很大的不足,其理论研究成果远远滞后于工程应用。目前有关双排桩支护结构的计算模型有多种,但还没有一种能被广泛接受和认可的计算方法来反映双排桩的桩排距、连梁刚度或尺寸、桩长与桩径等因素对支护结构受力的影响；目前工程界针对双排桩的设计采用的是国家规范和地区规程中的计算方法但是实践表明该方法亦有一定的局限性。本文在此基础上进行了更加深入的探讨,主要研究内容如下：首先本文总结了双排桩支护结构几种典型的布桩形式及常用的计算理论,并分析这几种计算理论的基本原理、适用范围及不足之处。其次本文分析了大刚度排桩对滑移面的影响,提出悬臂式双排桩结构破坏时滑移面向下移动,并对双排桩支护结构的弹簧模型进行改进,探讨不同埋深处的土层压缩模量变化规律,并重新建立双排桩计算模型。根据该模型讨论了同等支护条件下不同桩间土刚度及高低型双排桩对前后排桩弯矩及位移的影响。最后,为进一步探讨影响双排桩支护结构的主要因素对桩身弯矩位移的影响情况,本文以昆明市某基坑支护工程为背景,通过有限差分软件FLAC3D模拟基坑的开挖及支护过程,着重分析排距、前后桩长、连梁刚度及桩间土刚度等因素对桩身弯矩及位移的变化规律,与实际工程监测数据对比分析,并验证前面对推导理论公式的可行性。结果亦表明该理论成果具有一定的工程实用价值。
[Abstract]:As a new type of support structure, double-row pile supporting structure has good effect in controlling the lateral displacement of foundation pit, convenient construction, saving underground space and so on, and has been favored by the vast number of engineers. However, from the practical application of double-row piles, the existing design and calculation theory is still very inadequate because of the complex force of the supporting structure itself, and the theoretical research results lag far behind the engineering application. At present, there are many kinds of calculation models about double-row pile supporting structure, but there is no widely accepted and accepted calculation method to reflect the pile spacing, stiffness or size of connecting beam. The influence of pile length, pile diameter and other factors on the force of supporting structure. At present, the design of double-row piles is based on the national code and regional rules, but the practice shows that this method also has some limitations. On this basis, this paper makes a more in-depth discussion, the main research contents are as follows: Firstly, this paper summarizes several typical pile layout forms and common calculation theories of double-row pile supporting structure, and analyzes the basic principle, applicable scope and deficiency of these calculation theories. Secondly, this paper analyzes the influence of large stiffness piles on the slip plane, puts forward that the sliding plane moves downward when the cantilever double-row pile structure is destroyed, and improves the spring model of the double-row pile supporting structure. The variation law of soil compression modulus in different depth of buried soil is discussed, and the calculation model of double row pile is re-established. According to the model, the influence of soil stiffness between different piles and double row piles of high and low type on bending moment and displacement of front and rear row piles under the same supporting condition is discussed. Finally, in order to further discuss the influence of the main factors of double-row pile supporting structure on the moment displacement of pile body, this paper simulates the excavation and supporting process of foundation pit by using finite difference software FLAC3D, taking a foundation pit support project in Kunming as the background. The variation law of pile bending moment and displacement caused by such factors as row distance, pile length before and after, stiffness of connecting beam and soil stiffness between piles are analyzed and compared with the monitoring data of actual engineering, and the feasibility of deducing the theoretical formula is verified. The results also show that the theoretical results have certain engineering practical value.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU473.1

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