TRD工法在黄河冲积平原地区基坑支护中的应用研究

发布时间：2018-05-04 22:13

本文选题：TRD工法 + 深基坑　；参考：《河南工业大学》2017年硕士论文

【摘要】：随着城市规模的不断扩大和城市土地供应的限制,高层建筑已随处可见,地铁、管廊建设日益增多,随之出现的深基坑工程也越来越多。TRD工法作为一种新型的水泥土搅拌连续墙施工工法,通过研究发现,该工法具有止水性好、深度方向均匀等特点,在黄河冲积平原地区具有很好的应用前景。本课题以黄河冲积平原某深基坑工程为例,对工程分别采用TRD工法与钻孔灌注桩进行计算,对比分析其受力特性。之后对TRD工法围护墙体采用不同嵌固深度、墙体厚度及支锚刚度的受力变形进行研究。最后,利用ABAQUS软件对该基坑工程进行了模拟开挖,研究土体、墙体及钢支撑的受力及位移特性。本文的主要研究结论如下:(1)TRD工法支护墙体具有止水性好、墙体深度方向均匀、设备安全等特点。(2)以黄河冲积平原地区某深工程基坑为例,使用该工法进行设计计算,结果表明,TRD工法墙体有很高的支护、挡土效果,开挖完成后其支护结构的水平位移要比钻孔灌注桩小2.87mm,计算出的沉降量比钻孔灌注桩小3mm。(3)在满足嵌固深度基本要求的前提下,适当增加墙体嵌固深度可有效降低土体沉降量,但超过一定限值时,减低土体的沉降效果会减弱;保持TRD工法中型钢参数不变,适量改变TRD工法墙体厚度,发现作用于围护墙体的弯矩、剪力主要由型钢承担;适当调整支锚刚度的大小可有效降低围护墙体的最大弯矩和最大剪力,也可有效的降低基坑周围土体的地表沉降。(4)运用数值模拟方法对某深基坑工程进行模拟分析,研究不同工况下开挖的成效,发现随着基坑向下不断开挖,其地表沉降在4mm左右波动,周围土体沉降主要发生在墙体最大深度以上至土体表面区域;TRD工法支护墙体最大水平位移发生在距离坑底较近部位;钢支撑最大应力值发生在钢支撑中间段,而随着与围护结构侧壁间距的减小,应力也逐渐降低。
[Abstract]:With the continuous expansion of urban scale and the restriction of urban land supply, high-rise buildings have been found everywhere, and the construction of subway and pipe corridors is increasing day by day. There are more and more deep foundation pit engineering. TRD method is a new construction method of cement soil mixing continuous wall. Through the research, it is found that the method has the characteristics of good water sealing and uniform depth direction. It has a good application prospect in the Yellow River alluvial plain area. Taking a deep foundation pit project in the Yellow River alluvial plain as an example, the TRD method and bored pile are used to calculate the engineering, and the stress characteristics are compared and analyzed. Then the deformation of TRD retaining wall with different embedded depth, wall thickness and anchor stiffness is studied. Finally, the excavation of the foundation pit is simulated by using ABAQUS software, and the mechanical and displacement characteristics of soil, wall and steel braces are studied. The main conclusions of this paper are as follows: (1) the wall supporting wall with TRD method has the characteristics of good water sealing, uniform depth direction and safety of equipment, etc.) taking a deep engineering foundation pit in the Yellow River alluvial plain area as an example, the method is used to design and calculate. The results show that the wall with TRD method has high retaining effect. The horizontal displacement of the retaining structure is 2.87 mm smaller than that of bored pile after excavation, and the calculated settlement is 3 mm. Properly increasing the embedded depth of the wall can effectively reduce the settlement of the soil, but when the value exceeds a certain limit, the effect of reducing the settlement of the soil will be weakened, while keeping the parameters of the profile steel in the TRD method unchanged and changing the thickness of the wall of the TRD method in moderation, It is found that the shear force is mainly borne by the section steel, and the maximum bending moment and the maximum shear force of the retaining wall can be effectively reduced by adjusting the stiffness of the supporting anchor. It can also effectively reduce the surface settlement of soil around the foundation pit.) numerical simulation method is used to simulate and analyze a deep foundation pit project, and the results of excavation under different working conditions are studied. It is found that the excavation continues with the excavation down. The surface settlement fluctuates around 4mm, and the settlement of surrounding soil occurs mainly from the maximum depth of the wall to the area of soil surface. The maximum horizontal displacement of the wall is near to the bottom of the pit. The maximum stress value of steel bracing occurs in the middle of steel bracing, and the stress decreases gradually with the decrease of side wall spacing between steel braces and enclosure structures.
【学位授予单位】：河南工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU753

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