【作者】 闵紫超；

【导师】 洪宝宁；

【作者基本信息】 河海大学 ， 岩土工程， 2006， 硕士

【摘要】 湿喷桩因其在施工、技术、经济等方面的优势,近年来在高速公路软土地基处理中得到了广泛的应用,特别是在处理含结构物路段、桥头过渡段和地质条件较差特殊路段中发挥着巨大作用。然而,由于对湿喷桩强度的影响因素及其使用环境等方面的认识不足(如地场温度和土层性质对湿喷桩强度的影响等),在实际工程应用中,常常因为桩体强度不足或在没有达到要求情况下进行路堤填土施工,从而导致一系列的病害,如由于复合地基承载力不足而造成的路堤沉陷、路面开裂等。为了使湿喷桩这种施工工艺简单、经济实用的桩型在软基处理中发挥更大的作用,同时避免不必要的损失,深入系统地进行研究是必要的。本文结合连盐高速公路课题,从多个方面来探讨养护温度和素土性质对湿喷桩桩体强度所起的作用,并且在模型试验中综合考虑了养护温度和地基土性质对湿喷桩承载力的影响,从而可以较全面的考虑影响现场湿喷桩质量的因素。本文的研究成果对完善复合地基理论、控制现场施工质量等均有益处,并将产生良好的经济效益和社会效益。本文主要工作如下: 1) 利用连盐高速公路现场的两种土制成水泥土,并行进行不同养护温度,不同龄期下的无侧限抗压强度试验,分别探讨养护温度、龄期、地基土种类对无侧限抗压强度,变形模量等强度参数的影响。 2) 分析了水泥土微细结构和宏观物理力学性质的内在联系,从微细观层次上讨论了土层性质和养护温度变化对水泥土强度的影响。 3) 进行了不同季节的模型槽内压桩试验,测量了试验桩的承载力和相应的沉降量,用以分析土层性质和养护温度对湿喷桩承载力的影响。养护温度取各湿喷桩养护期的平均气温。 4) 在模型槽中专门打设用于测试材料强度的湿喷桩,并将测量得到的材料参数应用于湿喷桩的数值计算,从而得到温度和土层性质变化对湿喷桩承载力的影响,并且分析了两者对湿喷桩承载力的影响程度,从中得到了模型槽中不同条件下的试验桩加载变形的数值解。更多还原

【Abstract】 For its advantages in construction, technology and economy, WJP has been widely used in groundwork improvement of soft ground foundation in highway construction these years. It plays an important role especially in transition section or in the sections of the highway on bad geologic conditions or in the sections which include structures inside. However, for the insufficiency of the knowledge of how the factors and surroundings affect the quality of WJP (such as the ground temperature and soil properties),on the work field, the construction of filling soil is usually carried out before the WJP achieves its qualified strength, and this leads to series of accidents, such as the settlement of embankment 、dehiscence of pavement, which is lead by lack of the bearing capacity. It is necessary to study it in a deep-going and systematic way to make the WJP-which is simple to construct, economical and practical, play a more import role in the groundwork improvement of soft soil groundwork, and avoid unnecessary lose. This paper combines the project of LIAN-YAN highway, discusses the effect of the curing temperature and the properties of soil on the strength of the WJP material, and study the effect of the curing temperature and the properties of soil on bearing capacity of WJP in the model experiment together, so it is possible to take the factors which affect the quality of the WJP into account, and improve the theory of composite foundation, control the construct in field and get good social benefit and economic benefit. The work in this paper contains several parts:1) Make cement-stabilized soil using two kinds of soil from the work field of Lian-Yan highway, cure them under different temperatures for different ages, then carry out unconfined compression test, and estimate the effect of the temperatures, ages and the kinds of soil on the strength such as unconfined compression strength and modulus of deformation.2) Research the relationship between microscopic structure and macroscopic physical and mechanical properties, study the effect of the temperatures and theproperties of soil on the strength of the cement-stabilized soil.3) To study the effect of the maintaining temperature and the properties of soil on the bearing capacity of WJP in the model experiment, this part contains mainly experiment on the bearing capacity of the WJP in different seasons, then compare’ them, and consider the effect of the curing temperature, the soil properties on the bearing capacity of WJP, and evaluate the effect. Take the average temperature in the curing time as curing temperature.4) Drive WJP in the model box specially used for testing the strength of material, use the material parameters in the numerical simulation of WJP, then we can know the effect of ground temperature and soil properties on the bearing capacity of WJP, and measure the level of them, and get the numerical varying law of the deformation ofWJP in the model under different condition.更多还原