采动区地基与基础增湿过程中相互作用模拟试验研究

发布时间：2018-04-17 03:30

本文选题：地表变形 + 地基基础　；参考：《河南理工大学》2014年硕士论文

【摘要】：地下开采引起的地表变形改变了地基基础的初始接触状态,给上部建筑物的安全造成威胁。利用地基增湿具有的改善变形特性,使局部地基软化,改善地基基础的接触状态,可以达到保护上部建筑物的目的。自行设计制作了多功能采动变形相似模拟试验台,具有模拟地表曲率变形和压缩变形、实现局部地基注水增湿、重复采动下岩层移动、不同倾角煤层开采等功能。利用多功能试验台完成了地表不同曲率变形的模拟试验,获得了变形过程中地基反力变化规律。结果表明:随着地表曲率变形的增大,地基反力的畸变越严重。当正曲率变形为0.7mm/m2时,局部地基反力从初始状态的0.01Mpa增大到0.07Mpa;当负曲率变形为0.7mm/m2时,局部地基反力从0.02Mpa增大到0.11Mpa。地表发生曲率变形后产生的不均匀地基反力会严重影响上部结构的安全。在地表曲率变形的基础上,完成了局部地基注水增湿试验,获得了增湿过程中的地基反力变化规律。结果表明:随着注水量的增多,畸变的地基反力得到较大的改善。当正曲率变形为0.7mm/m2时,在地基中部注水7.5758L后,局部最大的地基反力从0.07Mpa减小到0.01Mpa;当负曲率变形为0.7mm/m2时,在基础两端部注水11.558L后,局部最大的地基反力从0.11Mpa减小到0.04Mpa。地表发生曲率变形时,在地基的承载区注水,可以改善地基与基础的接触状态,能够降低不均匀的地基反力,提高建筑物的安全系数。增湿过程中墙体的最大沉降量为21.4mm,不会引起地基的坍塌和失稳,增湿后土体含水率的最大差异为6.29%,局部土体的孔隙比下降,地基的承载力得到提高,表明采用局部增湿软化地基改善地表变形引起的不均匀地基反力是可行的。基于二元介质模型,建立了增湿地基的平均应力应变与注水量的关系,运用计算地基沉降的分层总和法原理,推导出增湿后地基沉降的预估公式,并对沉降量的理论值和实测值进行了分析。
[Abstract]:The ground deformation caused by underground mining changes the initial contact state of the foundation and threatens the safety of the upper building.The purpose of protecting the upper building can be achieved by using the humidification of the foundation to improve the deformation characteristic, to soften the local foundation and to improve the contact state of the foundation.A multifunctional similar test rig for mining deformation was designed and made, which can simulate surface curvature deformation and compression deformation, realize water injection and humidification of local foundation, rock stratum movement under repeated mining, and mining coal seam with different dip angle, etc.The simulation test of different curvature deformation of the ground surface was completed by using a multifunctional test bed, and the variation law of the foundation reaction force during the deformation process was obtained.The results show that with the increase of surface curvature deformation, the distortion of foundation reaction becomes more serious.When the positive curvature deformation is 0.7mm/m2, the local foundation reaction force increases from 0.01Mpa to 0.07Mpa.When the negative curvature is 0.7mm/m2, the local subgrade reaction force increases from 0.02Mpa to 0.11Mpa.The safety of superstructure will be seriously affected by the non-uniform foundation reaction after the curvature deformation of the surface.On the basis of the surface curvature deformation, the local foundation water injection humidification test was completed, and the variation law of the foundation reaction force during the humidification process was obtained.The results show that with the increase of water injection, the reaction force of the distorted foundation is greatly improved.When the positive curvature deformation is 0.7mm/m2, the local maximum ground reaction force decreases from 0.07Mpa to 0.01MPA after 7.5758L injection in the middle of the foundation, and when the negative curvature deformation is 0.7mm/m2, the local maximum ground reaction force decreases from 0.11Mpa to 0.04Mpa. when the water injection is 11.558L at both ends of the foundation.When curvature deformation occurs on the ground, water injection in the bearing area of the foundation can improve the contact state between the foundation and the foundation, reduce the non-uniform foundation reaction force, and increase the safety factor of the building.In the process of humidification, the maximum settlement of the wall is 21.4mm, which will not cause the collapse and instability of the foundation. The maximum difference of soil moisture content after humidification is 6.29, the void ratio of the local soil decreases, and the bearing capacity of the foundation is improved.It shows that it is feasible to use local humidifying and softening foundation to improve the reaction force of uneven ground caused by surface deformation.Based on the binary medium model, the relationship between the average stress and strain of the humidified foundation and the quantity of water injection is established. By using the principle of stratified summation method to calculate the settlement of the foundation, the prediction formula of the foundation settlement after the humidification is derived.The theoretical and measured values of settlement are analyzed.
【学位授予单位】：河南理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TD325;TU470

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