深基坑变形机理与控制技术研究

发布时间：2018-03-28 04:13

本文选题：深基坑　切入点：ABAQUS　出处：《安徽理工大学》2014年硕士论文

【摘要】：本文首先利用深基坑变形机理清楚的揭示墙体变形、基坑底部隆起、墙后地表沉降三者之间变形现象的原因,由此,可得出三者之间的变形是相互联系的：挡土墙内外侧土压力差使其产生向坑内方向的变形,导致墙后土体产生了竖向位移；坑底部土体原始应力状态因垂直卸载而回弹,产生了以向上为主的位移,导致坑底土体隆起。文中用正态分布概率密度函数描绘通过最大下沉点剖面的地表沉降曲线和由最小二乘法求得的挡土墙侧向位移拟合曲线,利用二者之间的函数关系推导出任意点最大沉降值的计算公式,这对预测基坑周围土体沉降大小和地下管道的变形有着重要的作用。采用ABAQUS模拟了土钉—桩锚支护,更直观的分析不同开挖层面土钉及锚杆内力和桩体位移。结果证明：桩体的侧向位移逐渐减小,并呈下降趋势,土钉—桩锚支护对改善基坑变形控制起到了重要的作用。本文还介绍了不同的支护类型。在现实工程中可根据基坑深度、周围环境、地质水文、经济等综合考虑,选择合适的支护结构,为深基坑工程提供安全和稳定。结合淮北市金鹰商厦基坑支护的工程实例,详细介绍该工程土钉—桩锚支护设计方案及工艺,并对测点进行沉降监测：地面沉降观测点的变形率逐渐降低,基坑处于稳定状态。
[Abstract]:In this paper, the deformation mechanism of deep foundation pit is first used to reveal the causes of deformation between wall deformation, bottom uplift of foundation pit and surface settlement behind wall. It can be concluded that the deformation between the three is interrelated: the difference of the earth pressure inside and outside the retaining wall causes the deformation in the direction of the pit, which results in the vertical displacement of the soil behind the wall, and the original stress state of the soil in the bottom of the pit bounces back because of the vertical unloading. In this paper, the surface settlement curve of the maximum subsidence point profile and the lateral displacement fitting curve of the retaining wall obtained by the least square method are described by normal distribution probability density function. The calculation formula of maximum settlement value at any point is deduced by using the function relation between them, which plays an important role in predicting the settlement of soil around foundation pit and the deformation of underground pipeline. The soil nailing and pile anchor support are simulated by ABAQUS. The results show that the lateral displacement of the pile decreases gradually and shows a downward trend. Soil nail-pile anchor support plays an important role in improving the deformation control of foundation pit. This paper also introduces different types of support. According to the comprehensive consideration of the depth of foundation pit, surrounding environment, geology and hydrology, economy and so on, the suitable supporting structure can be selected in practical engineering. To provide safety and stability for deep foundation pit engineering, this paper introduces the design scheme and technology of soil nail-pile anchor support in detail according to the engineering example of foundation pit support of Jinying commercial building in Huaibei City. The deformation rate of the ground subsidence observation point decreases gradually and the foundation pit is in a stable state.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU753

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