软土地区新型深基发坑支护方法的研究一直是国内研究和开....doc

PAGE PAGE 1 摘 要 软土地区新型深基坑支护方法的研究一直是国内研究和开发的热点。本文通过对混凝土与水泥土咬合桩基坑支护可行性试验研究，根据其作用机理，提出可充分发挥材料的作用的合理设计方法，为深基坑支护工程提供一种技术可靠、占地少、经济、环保的新型基坑支护方法。 本文是通过收缩性试验，研究了不同土质、含水量、不同水泥掺入比的水泥土试样在不同龄期的收缩性，分析了水泥土试样收缩性与土质、含水量、水泥掺入比及龄期等因素之间的关系；通过渗透性试验，研究了不同配比的水泥土与混凝土咬合桩模型咬合面的渗透性，分析了影响咬合面渗透性的各种因素；通过水泥土模型梁的弯曲试验，研究了梁的破坏形式、在不同荷载作用下的挠度变化规律及破坏时的极限挠度。研究表明：水泥土试样在各种因素下，总体呈膨胀趋势；水泥砂土与混凝土咬合桩能抵抗较大的孔隙水压力，满足抗渗止水的要求；水泥土梁的破坏形式为脆性破坏，刚度较小，不同荷载作用下梁中间的挠度总是最大。最后结合现场咬合桩试用监测结果综合分析表明，混凝土与水泥土咬合桩作为一种新型的基坑支护方法应用于基坑支护是完全可行的。 关键词： 混凝土与水泥土咬合桩 基坑支护 收缩性 渗透性 挠度 PAGE Abstract The new method of deep in soft-soil areas is a hot issue of domestic research and development in china .Through the experiment research of the possibility of the stake which matched up concrete stake with the soil-cement stake. According to its function mechanism, this paper puts forward a rational design method which fully gives play to the role of the materials. Then provides the protection of foundation pit supporting engineering a new kind of reliable and economic method which covers little land, affect little influence on environment. Through contractility experiment, studying the soil-cement tries’ contractility in different soil property, different amount of water, various cement adding ratio during different period. And then analyzing the result, find out the relations between contractility and the various factors. Through permeability experiment，studying the permeating properties of the stakes model which matched up concrete stake with soil-cement stake, then analyzing the various factor which affect the permeating properties of the composite stake. Through bending tests with the model of soil-cement beam under different loads, studying the breakage form of the beam, the change regulation of the beam’s deflection, and the limit deflection when it damages. Through above studying and analyzing, the soil-cement tries present inflating trend under various factors. The stakes model which matched up concrete stake with sandy-cement stake