【作者】 井浩；

【导师】 邵生俊；

【作者基本信息】 西安理工大学 ， 岩土工程， 2008， 硕士

【摘要】 顶推箱涵施工是箱涵通过既有建筑物或构筑物形成地下通道的一种重要工程技术。在箱涵顶进施工过程中,为了减小顶进推力和作用于周围土体的荷载,已经广泛应用土体与箱涵接触面注入膨润土浆液形成泥浆套的减阻技术。本文从认识注浆型接触面泥浆特性、试验揭示箱涵与土体接触面泥浆套形成机理、应用注浆劈裂理论分析接触面泥浆扩散传递范围、实际施工中应用泥浆套减阻技术等方面开展研究,取得了有益认识。本文设计开发了一套能够真实模拟箱涵壁压注泥浆的仪器,通过试验模拟砂土和黄土与箱涵外侧壁接触面以及模拟注浆形成泥浆套,在不同密度和土压力条件下,测试了泥浆扩散范围和模式,分析了砂土及粘性土接触面泥浆扩散半径的影响因素和规律。同时,模拟箱涵外壁与浆土混合物之间的剪切作用,测量模拟面板与浆土混合物间的摩擦系数,得出了模拟面板与浆土混合物间的最大静摩擦系数以及滑动摩擦系数随质量比的变化规律。膨润土泥浆具有触变性、渗透性、浸透性。膨润土泥浆膜具有隔离作用、减阻作用、防渗作用和支撑作用。致密土体的注浆是一个复杂的流体或颗粒体材料劈裂注入土体的过程,泥浆套的形成过程也包括三个主要阶段：压密阶段、劈裂流动阶段和被动土压密阶段。应用注浆劈裂理论分析了模拟注浆测试结果,测试结果与计算结果具有很好的一致性。表明在致密土体中箱涵顶进时应用该理论预测有效的注浆压力和泥浆传递扩散范围具有可靠性。结合实际工程中顶推力的实际监测数据进行了分析。通过对比理论计算顶推力和实际测试结果,进一步验证了模拟试验中所得到的面板与各浆土混合物间的摩擦系数的合理性。更多还原

【Abstract】 Jacting Box culvert Method is a very impotant technique which Pass the Existed building and Forms the underground Passage. The technology of Diminish the friction between box culver and soil have used extensively, In order to grow down the thrust and load of soil body. This paper got the beneficial cognition through learn the slurry characteristic property of the injecting interface, reveal the seepage mechanism of the slurry covering between the box culvert wall from the test, applying the theory of fracturing grouting analysis the slurry diffusion radius at interface.The author designed a instrument which can simulate the process of injecting the slurry to the box culvert wall, then test the rule of the slurry jacket’s formation and the diffusion radius in the different soil texture and different soil prussur, The analog experiment simulate the sand and loess. Analysed the laws and the factors that influences of the slurry diffusion radius at interface in sand and cohesive soil. Meantime, the author simulated the cutting bentonite mixture in the process of the box culvert-pushed and surveyed the friction coefficient of the simulated faceplate and all kinds of the mixture to obtain the rule of the change between the biggest coefficient of friction of the simulated faceplate and the mass ratio.Bentonite slurry have the properties of thixotropy and penetrability. The Bentonite slurry film have the effect of segregant, diminish the friction, antiseepage and support. The grouting in low-permeability soil is a complex process of fracturing grouting about fluid or granule. There are three processes of slurry covering formation:densification, fracturing flowage and passive earth densification. applying the theory of fracturing grouting analysis the tests result. Test result and calculation bear fruit having very good compatibility. This indicated it is reliability that using the theory of fracturing grouting predicted the grouting press and the diffusion radius in jacting box culvert.In the end,the author analysed the test data compare to the actual project. The formula to calculate the resistance of the box culvert was deduced.This task get a step further to confirm the correctness of the coefficient of friction obtained in the experiment.更多还原