【作者】 乔国刚；

【导师】 陶龙光；

【作者基本信息】 中国矿业大学（北京） ， 岩土工程， 2009， 博士

【摘要】 土压平衡盾构穿越复杂地层时,必须采取土体改良措施,目前泡沫改良土体已被广泛应用于盾构施工中。我国尚未开发出可替代国外产品的优良泡沫添加剂,伴随盾构国产化进程加快,泡沫添加剂研发与泡沫土性能研究非常迫切。本文围绕土压平衡盾构用新型泡沫剂的开发研制和地铁建设中土压平衡盾构穿越复杂地层时的泡沫剂土体改良的相关特性参数进行研究。在分析进口泡沫剂成分的基础上,运用正交试验方法,开展了新型土压平衡盾构用泡沫剂的研制工作,对自制泡沫剂、进口泡沫剂和国产泡沫剂的基本性能进行对比试验,并对泡沫剂的特性评价标准提出了量化指标；以自制泡沫剂、进口泡沫剂和国产泡沫剂为土体改良材料,开展了泡沫改良砂土和粘土的渗透性、塑流性、剪切强度、压缩性、外摩擦角的对比实验研究,对改良土的各项特性指标进行了综合分析,提出了改良土“塑性流动性”特性评价试验室标准和量化指标；在对红粘土和砂土微观结构研究的基础上,进行了泡沫改良砂土和粘土的微观机理研究。更多还原

【Abstract】 Soil improvement measures must be taken when EPB shield tunnel in the complex strata, at present, the method of foam modifying soil has been widely used in shield construction. In our country, foaming agent has not yet been developed to replace the exellent abroad products, with the accelaration of localization of shield machine, the research on foaming agent and the properties of the foamed soil are very urgent. On the R& D of a new type of foaming agent used in EPB shield and foam improving soil for tunneling in the complex strata in the subway construction. Based on the composition analyzing of imported foaming agent, the orthogonal test method is adopted to carry out the development of a new type of foaming agent used in EPB shield machine. The basic performances are compared with the homemade foaming agent, imported foaming agent and dometic foaming agent, and the quantitative evaluation criteria on the characteristics of foaming agent is put forward; taking the home-made foam, domestic foam and imports foam as soil improving materials, the experimental research on the permeability, plastic flow, shear strength, compression and external friction angle of foam improved sand and clay is carried out. Based on the comprehensive analysis of the characteristic indexes of the modified soils, the quantitative evaluation criteria on the "liquid plastic" properties of the foam modified soil is put forward; based on the research of microstructure of sand and clay, the research on micro-mechanism of foam improving sand and clay is carried out.更多还原