现浇薄壁筒桩工作性状与应用研究

发布时间：2018-01-03 13:01

本文关键词：现浇薄壁筒桩工作性状与应用研究　出处：《浙江大学》2013年博士论文　论文类型：学位论文

【摘要】：大直径现浇混凝土薄壁筒桩(CTP)作为一种新桩型,目前已在我国的公路软基处理、海堤及码头工程、深基坑围护、建筑物基础处理等工程中得到广泛的应用。然而,该种桩型的理论研究远落后于工程应用,随着应用范围的日益扩大,对其理论分析、试验研究以及计算方法的研究、探讨和分析变得日益迫切。目前国内对CTP桩在竖向荷载作用下的性状进行了大量的分析,然而对其在水平荷载作用下的性状研究却较少,这严重制约着CTP桩的推广与应用。针对这些问题,本文在前人研究的基础上,首先介绍了高速公路CTP桩加固路堤的试验研究情况,然后推导了CTP桩土水平抗力的解析解,编程分析了CTP桩抗水平力性状,对CTP桩海堤和基坑围护进行了研究,所做的工作如下： 1)根据广东珠江三角洲环形高速公路西环段的现场试验和观测数据,分析了CTP桩桩承式加筋路堤的荷载-沉降、抗滑移等工程性状以及拉膜效应和土拱效应的作用。 2)根据考虑变形效应的主被动土压力与桩-土间摩擦力理论,并参考前人对圆筒结构土抗力分布的研究成果,推导出CTP桩在某深度处的水平抗力H(z,y)的解析解并与目前常用的几种方法进行了比较,进而分析了不同桩土参数下的大直径CTP桩的H-y曲线。 3)根据CTP桩水平抗力解析计算结果,从刚性桩和柔性桩两种情况,分别把桩视为刚性体和弹性地基梁,应用有限差分法,编制计算程序,求解CTP桩的变形和内力,并与现场试验数据和其他方法进行比较,检验此方法的适用性,进而分析桩、土各参数对CTP桩水平受力性状的影响。研究显示,该方法可以考虑土抗力的非线性和有限性(即不随位移的增加而无限增大),比目前常用的m法更接近实际,比p-y曲线法更容易取得参数。 4)介绍了CTP桩海堤和基坑支护体系特点和计算方法。在前文单桩抗水平力分析方法基础上,计算分析了CTP桩海堤和基坑支护体系的内力和位移,并分析了各因素对其的影响。
[Abstract]:As a new type of pile, large-diameter cast-in-situ concrete thin-walled tube pile has been used in highway soft foundation treatment, seawall and wharf engineering, and deep foundation pit protection. Building foundation treatment and other projects have been widely used. However, the theoretical study of this type of pile is far behind the engineering application, with the increasing expansion of the scope of application, the theoretical analysis of this kind of pile. Experimental study and calculation method research, discussion and analysis become more and more urgent. At present, there is a lot of analysis on the behavior of CTP pile under vertical load, but there is little research on the behavior of CTP pile under horizontal load. This seriously restricts the popularization and application of CTP pile. In view of these problems, this paper first introduces the experimental research on the reinforcement of embankment with CTP pile in expressway on the basis of previous research. Then the analytical solution of horizontal resistance of CTP pile and soil is derived, and the horizontal resistance behavior of CTP pile is analyzed by programming. The research on the seawall and foundation pit enclosure of CTP pile is carried out. The work done is as follows: 1) the load-settlement of CTP pile supported reinforced embankment is analyzed based on the field test and observation data of west ring section of Guangdong Pearl River Delta circular highway. Engineering properties such as slippage resistance and the effects of film drawing and soil arch effects. 2) according to the theory of active and passive earth pressure and pile-soil friction considering deformation effect, and referring to the previous research results of soil resistance distribution of cylindrical structure. The analytical solution of the horizontal resistance of CTP pile at a certain depth is derived and compared with several commonly used methods. Furthermore, the H-y curves of large diameter CTP piles with different soil parameters are analyzed. 3) according to the analytical results of horizontal resistance of CTP pile, the pile is regarded as rigid body and elastic foundation beam respectively from the two cases of rigid pile and flexible pile, and the calculation program is compiled by using finite difference method. The deformation and internal force of CTP pile are solved, and compared with the field test data and other methods, the applicability of this method is tested, and then the pile is analyzed. The influence of soil parameters on the horizontal behavior of CTP pile. The study shows that this method can take into account the nonlinearity and finiteness of soil resistance (that is, it does not increase infinitely with the increase of displacement). It is closer to reality than the m method, and it is easier to get the parameters than the p-y curve method. 4) the characteristics and calculation method of CTP pile seawall and foundation pit support system are introduced. On the basis of the previous analysis method of single pile anti-horizontal force, the internal force and displacement of CTP pile seawall and foundation pit supporting system are calculated and analyzed. The influence of various factors on it is also analyzed.
【学位授予单位】：浙江大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU473.1

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