旋喷桩加固泥炭土路基有限元分析

发布时间：2018-04-09 06:16

本文选题：泥炭土　切入点：新型固化剂　出处：《昆明理工大学》2014年硕士论文

【摘要】：随着社会发展,城市的规模越来越大,城市道路里程也是突飞猛进,这就使得很多城市在建设道路时必然会触及泥炭土。泥炭土主要分布在我国东北、东南、西部高原等大多地区,具有含水量高、触变性很强的特性,因此必须对其进行加固。泥炭土加固方案有许多种,其中又以采用固化剂加固的方式最为实用。现已通过大量实验研究得知某种新型固化剂对泥炭土的加固效果比较好,但是对采用此种固化剂旋喷桩加固的路基在车辆动静荷载作用下的力学性能却不甚清楚。鉴于此,本文在以此种固化剂加固滇池泥炭土的基础上,利用ANSYS建立了该地区道路路基的三维模型,在建模过程中重点介绍了桩体参数的选取、考虑滑动情况下等厚度桩-土接触面的参数设置及荷载施加的位置与方式,建模后分别对路基在静力荷载和动力荷载作用下的位移与应力进行了计算和分析。其中静力部分主要分析了：(1)有新型固化剂旋喷桩加固与无桩加固情况下路基模型三个方向的应力与位移变化趋势及对比,(2)荷载作用在不同车道及所有车道对整个路基的影响,(3)利用弹性力学计算的理论数据与模拟数据进行了对比分析；动力部分主要分析了：(1)在不同速度下路基的位移与应力时程曲线,(2)对动力结果与静力结果的应力最大值进行了比较。针对以上研究,本文主要结论有： (1)所有情况下路基应力和位移都随着离荷载作用位置距离的增加而降低,其中采用了新型固化剂旋喷桩加固相对于无桩加固而言,其竖向应力及位移值小很多； (2)所有车道同时加载时路基的位移与应力不能单纯的由单个车道逐个叠加；荷载全部作用在旋喷桩顶上方对桩体影响最大,荷载作用在桩间土时影响最小且变化更加均匀； (3)动力时程曲线形式完全与半波正弦荷载形式相一致； (4)动力与静力分析结果差距不大,因而在道路等级较低的情况下,只需要进行静力分析。
[Abstract]:With the development of society, the scale of the city is getting larger and larger, and the road mileage of the city is also advancing by leaps and bounds, which makes many cities inevitably touch the peat when building the road.Peat is mainly distributed in most areas of northeast, southeast and western plateau of China. It has the characteristics of high water content and strong thixotropy, so it must be strengthened.There are many kinds of peat soil reinforcement schemes, among which the consolidation with curing agent is the most practical.Through a large number of experimental studies, it has been found that a new curing agent has a good effect on the reinforcement of peat soil, but the mechanical properties of the roadbed strengthened by this kind of curing agent under the dynamic and static loads of vehicles are not very clear.In view of this, on the basis of strengthening the peat soil of Dianchi Lake with this kind of curing agent, the three-dimensional model of road roadbed in this area is established by using ANSYS, and the selection of pile parameters is introduced emphatically in the course of modeling.Considering the parameter setting of the pile-soil interface with equal thickness under sliding condition and the position and mode of load applied, the displacement and stress of roadbed under static load and dynamic load were calculated and analyzed respectively.In the static part, the stress and displacement trends of the three directions of the roadbed model under the condition of strengthening the roadbed model with a new type of solidifying agent, jet grouting pile, and no pile reinforcement, are analyzed and compared, and the load action on the whole roadway is compared in different driveways and all driveways.The influence of roadbed is compared with the simulation data by using the theoretical data of elastic mechanics calculation.The dynamic part mainly analyzes the displacement and stress time history curves of roadbed at different speeds.In view of the above research, the main conclusions of this paper are as follows:1) in all cases, the stress and displacement of the roadbed decrease with the increase of the distance from the loading position.(2) the displacement and stress of roadbed can not be superimposed by single driveway at the same time, the load acting on the top of the pile is the biggest, and the load is the least and the change is more uniform when the load is between the piles and the soil.3) the form of dynamic time history curve is completely consistent with the form of half wave sinusoidal load.4) the difference between dynamic and static analysis results is not large, so only static analysis is needed in the case of lower road grade.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.1

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