甘肃深厚湿陷性黄土场地地基处理

发布时间：2018-01-04 15:43

本文关键词：甘肃深厚湿陷性黄土场地地基处理　出处：《兰州交通大学》2015年硕士论文　论文类型：学位论文

【摘要】：随着当今社会经济的飞速发展,当代建筑越来越多的向着高层超高层、大规模以及异型结构的方向发展,这就使得各工程对于各个部位,特别是地基的承载能力要求也越高,在西北的深厚湿陷性黄土场地上的工程亦越来越多,由于黄土湿陷性的影响,使得很多建筑需要将基础做至基岩层或卵石层就必须向下延伸数十米甚至更厚才能满足地基规范对场地剩余湿陷的要求,费工费力且造价高昂,甚至有时会出现地基处理的造价高于上部结构的造价;因此,地基处理的深度广度的选择就显得尤为重要。本文结合工程实例,通过数值模拟和理论计算对湿陷性黄土地基场地的处理深度及广度进行讨论分析。主要通过以下方面讨论:1、进行土体的整体处理后,此时人工地基具有较好的强度、刚度及稳定性,透水性小,水体很难透过该土层发生下渗,而当水体透过人工地基边缘渗透到底部未处理的原状湿陷性黄土时,此部分土体遇水将会发生一定的湿陷变形,变形稳定后,假定该土层与人工填土相分离,去除这部分土体后考虑发生湿陷的面积对于人工填土的影响,从而比较得出地基浸水后所产生的湿陷部分面积的大小及所允许发生湿陷的最大面积,藉此讨论所需要的地基处理深度。2、对于局部位置,将桩基础视为复合型地基,与地基土地结合为强度增大后的整体,通过假定周围的未经处理的黄土遇水浸湿后产生一定的湿陷变形,此时,桩体复合地基形成了一定的支撑能力,类似于人体的骨骼,湿陷土体在其支撑下,仍然视为保持稳定;基于以上这一点分析讨论湿陷土体产生的下拉作用对于地基处理广度的影响。经过以上分析之后,对于深厚湿陷性黄土,不论是经过整体处理还是局部的处理,都可以达到增大土体强度、刚度及稳定性的作用,从而提高了地基抵御变形的能力;而桩体的复合型地基也可加强土体强度,平衡周围未处理土体由于湿陷所带来的下拉荷载,为局部处理的方案提供了一定的帮助。
[Abstract]:With the rapid development of society and economy, more and more toward the contemporary building high-rise, large-scale and special structure of the direction of development, which makes the project for each part, especially the requirements of the foundation bearing capacity is also higher, in the northwest of the deep collapsible loess site works are also more and more, because of the influence of loess collapsibility, make a lot of construction needs to be based to the bedrock layer or the gravel layer must extend down tens of meters or more thick foundation can meet the specification requirements for the remnant collapse site, a lot of work and effort and cost, and even sometimes the cost of foundation treatment is higher than that of the upper structure of the cost; therefore, the depth and breadth of foundation the treatment of choice is very important. This paper combined with the engineering example, through numerical simulation and theoretical calculation of the width and depth of collapsible loess foundation site Discussion and analysis. Through the following aspects: 1, the overall process of soil, the artificial foundation has good strength, stiffness and stability, permeability, water is difficult to occur through the soil infiltration, and when the water through the artificial ground edge penetration to the bottom of the untreated undisturbed collapsible loess when the soil water will occur in the wet deformation, deformation and stability of soil, assuming that the phase separation and removal of the soil, artificial fill, after considering the collapsible area for artificial filling, thus comparing foundation after arising from the collapsible part size and allowed to happen the largest area of collapsibility, to discuss the depth of.2 foundation treatment is needed, for the local position, the pile foundation as the composite foundation, and the foundation for the overall land with greater intensity, by assuming that the week In the untreated loess water soaked after deformation, the wet the pile composite foundation formed supporting ability, similar to human bone, collapsible soil in its support, is still regarded as stable; impact down the above point analysis on collapsible soil for the foundation treatment based on breadth. Through the above analysis, the deep collapsible loess, either through the whole or local treatment can increase the soil strength, stiffness and stability, so as to improve the ability to resist deformation of the base; and the composite foundation pile can also strengthen the strength of soil, because the soil around the balance of untreated downdrag caused by the collapse, as local treatment programs provide some help.

【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU475.3

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