【作者】 孟繁钰；

【导师】 李新生；

【作者基本信息】 长安大学 ， 岩土工程， 2011， 硕士

【摘要】 目前,地裂缝已成为西安市城市建设的主要地质灾害,多年来给城市建设造成了巨大的经济损失,在城市规划发展方面也带来了一定制约。但随着控制开采地下水,地裂缝活动也明显减弱,人们希望能进一步利用地裂缝带土地资源与现有规范限制之间的矛盾日益加剧。所以,深入了解地裂缝的成因机理及影响范围,对促进该问题的研究和解决,降低经济损失都有十分重要的意义。本文研究的目的是分析出裂缝发展的一般性规律,包括裂缝的扩展方向和地裂缝上下盘的变形范围等问题,为进一步提高地裂缝带土地资源的利用率提供参考。研究思想是：万物有其相似的表现则必有其共同的本质。地裂缝的本质就是地层的断裂、开裂,它的形成机制类似于构造断层,但也有自身活动的个性：地裂缝的层地表展布和垂直形态与正断层相同,但由于过量开采地下水,地裂缝的活动量及其周期性又与正断层不同。本文运用材料力学、弹性力学的理论,基于地裂缝监测结果并使用有限元软件作为计算辅助,从静力学角度进行分析。首先,对于破裂面已存在的情况,分析了为何无论是大尺度的断层还是小尺度的地裂缝,其均是上盘比下盘破碎更严重,变形范围更大；并分析了土体压缩模量、边界位移、破裂面倾角和断面摩擦力等因素与地裂缝影响宽度的关系。其次,对于破裂面尚未形成的情况,分析了为何地裂缝破裂面的倾向和上部建筑裂缝倾向相反及近地表裂缝发展的形式多样的原因。提出裂缝扩展方向的主要影响因素是水平应力,但近地表裂缝扩展的多样性控制因素不仅有水平应力,还有土层力学性质。文中也浅谈了研究尺度和分析精度的问题,在一定程度上说明了本文建立的各线弹性模型的合理性。更多还原

【Abstract】 Ground fissure has become the most serious geological disaster in Xi’an at present. It not only brings about huge economic losses to urban construction over the years, but also restrict the city planning. However, the ground fissure activity receding obviously with the control of exploiting the underground water, the contradiction between the hope of using the ground fissure zone more and the restriction on the existing standard is growing. So that the in-depth understanding of both the happen and the development of the ground fissure has the vital significance to the reduce of the economic losses and also can promote the research and solution to the problem. The purpose of this article is acquiring the general rules of the ground fissure’s development including the issue that the ground fissure’s extension direction and the upper plate and footwall of ground fissure which can provide reference to the uses of the ground fissure zone.The research idea can be conclude as follows:different thing should have common essence if they have similar appearance. The essence of ground fissure is the fracture of strata. It has commonness with normal faults, and has personality of its own activity Ground fissure has similar appearance with normal faults for the surface exhibit and the vertical form, but they also have differences on the activity level and the periodicity which because of the excessive mining of groundwater. The article use the material mechanics and elastic mechanics theory, based on the monitoring results of ground fissure, with the computer aided of finite element software, analyse it from the statics angle. First of all, the fracture surface has already exists:whether the large-scale fault still the small-scale ground fissure, the footwall has more serious damage than the upper plate, and has larger deformation range. Besides, we analyse the main factors which has relationship with the ground fissure’s influence width such as the soil compression modulus, the boundary displacement, inclination of the fracture surface and the section friction. Secondly, the fracture surface hasn’t exists yet. We analyse why the tendency of ground fissure fracture surface is opposite to the one of upper building cracks and the reason why the development form of near-surface fissure is multiple. The article put forward that the main influencing factor of the fissure extension direction is horizontal stress, but the diversity control factor of the near-surface fissure is not only the horizontal stress but also the soil mechanics properties. We still talk about the research scale and the analysis precision problem in the article which proved the rationality of the linear elastic to a certain degree.更多还原