高速公路下伏采空区探测及稳定性研究

发布时间：2018-05-02 20:34

本文选题：采空区 + 高速公路　；参考：《辽宁工程技术大学》2015年博士论文

【摘要】：采空区对地表高速公路是一个巨大的潜在威胁,尤其是采空区的残余变形具有隐蔽性、复杂性、突然性及长期性的特点.目前,关于高速公路下伏采空区研究的文献主要以施工经验和实例介绍为主,理论研究的较少,从探测、监测、稳定性研究及治理等方面都缺乏足够的理论支持.因此,对高速公路下伏采空区探测及稳定性研究具有重要现实意义.通过理论分析建立了复杂荷载条件下采空区顶板—矿柱体系流变力学模型；根据高速公路下伏采空区特点,建立了采空区探测验证体系,并进行了修正；根据采空区实际情况,对传统位移监测仪器进行相关改进,增强了该仪器的适用性；针对高速公路与采空区相互作用影响进行了数值模拟分析,研究了采深、采厚、倾角、空区尺寸等因素对高速公路影响规律；提出采用粉煤灰泡沫混凝土作为充填体对采空区进行治理,并进行了相关的试验及数值模拟研究.主要研究成果如下：(1)建立了高速公路下伏采空区探测验证体系.提出了选用高密度电阻率法布置测线进行探测,采用特征位置钻孔取样、钻孔内声波探测及钻孔电视成像技术进行验证,采用平差方式对探测验证体系结论进行修正,最终确定高速公路下伏采空区位置及状态.(2)根据采空区实际情况,对传统监测仪器进行相关改进,增强了该仪器的适用性,并提出了钢管+活塞封底技术,有效的进行了钻孔封底、避免跑浆.(3)建立了复杂荷载条件下采空区顶板—矿柱体系流变力学模型,通过工程实例验证了该力学模型应用于采空区稳定时间预测的可靠性.(4)高速公路与采空区空间异面相交和高速公路与采空区走向一致情况下相比较,所产生的残余下沉数值及范围都要小于后者；随着采空区倾角增大,高速公路的残余沉降及水平位移逐渐减小,影响范围也逐渐减小；当采厚一定时,冒落和裂隙带高度趋于一定；采深越大,弯曲带厚度越大,下沉曲线的边界会变得很圆滑.同时研究了不同空区尺寸对采空区安全系数的影响.(5)运用MATLAB对高速公路下伏采空区在深厚比、倾角、充填效果因素影响下的高速公路变形进行多维插值,编制了残余变形最大值预测程序.(6)粉煤灰泡沫混凝土充填体抗压强度在0.4～2.8 MPa之间变化,能够满足一般采空区充填要求,且该充填体利用率较高,适合采空区充填.经试验及数值模拟验证,该充填体治理减沉效果可达到70%以上.
[Abstract]:The goaf is a huge potential threat to the surface highway, especially the residual deformation of the goaf has the characteristics of concealment, complexity, sudden and long-term. At present, the literature on the research of goaf under the expressway is mainly based on the construction experience and the introduction of practical examples, but the theoretical research is less, and there is a lack of sufficient theoretical support from the aspects of detection, monitoring, stability research and management. Therefore, it is of great practical significance to study the detection and stability of goaf under expressway. Through theoretical analysis, the rheological mechanics model of goaf roof pillar system under complex load is established, and according to the characteristics of goaf under expressway, the system of goaf detection and verification is established and corrected, and according to the actual situation of goaf, the model of rheological mechanics of goaf roof pillar system is established. By improving the traditional displacement monitoring instrument, the applicability of the instrument is enhanced, the interaction between expressway and goaf is simulated and analyzed, and the mining depth, mining thickness and inclination angle are studied. The influence of the size of the empty area on the freeway is studied, and the method of treating the goaf by using the fly ash foam concrete as the filling body is put forward, and the relevant experiments and numerical simulation are carried out. The main research results are as follows: (1) the system of detection and verification of goaf under expressway is established. The method of high density resistivity is used to arrange the measuring line for detection, and the characteristic position borehole sampling, the acoustic wave detection in the borehole and the borehole television imaging technology are used to verify it, and the conclusion of the detection verification system is corrected by the adjustment method. Finally determine the location and state of goaf under freeway. (2) according to the actual situation of goaf, improve the traditional monitoring instrument, enhance the applicability of the instrument, and put forward the steel tube piston bottom sealing technology. The rheological mechanics model of roof pillar system in goaf under complex load is established by effectively sealing the bottom hole and avoiding running slurry. The reliability of the mechanical model applied to the prediction of goaf stability time is verified by an engineering example. The reliability of the model is compared with that of the intersection of the spatial hetero-plane between the freeway and the goaf and the alignment of the expressway with the goaf. The value and range of residual subsidence are smaller than that of the latter. With the increase of goaf inclination angle, the residual settlement and horizontal displacement of freeway gradually decrease, and the influence range is gradually reduced; when the mining thickness is certain, The height of caving and fracture zone tends to be certain, and the bigger the mining depth, the greater the thickness of the curved zone, and the more smooth the boundary of the subsidence curve becomes. At the same time, the influence of different size of goaf on the safety factor of goaf is studied. The MATLAB is used to interpolate the deformation of freeway under the influence of deep ratio, inclination angle and filling effect factor. A program for predicting the maximum residual deformation is developed. The compressive strength of the fly-ash foamed concrete filling body varies from 0.4 to 2.8 MPa, which can meet the requirements of general goaf filling, and is suitable for the goaf filling due to its high utilization ratio. The results of experiment and numerical simulation show that the anti-subsidence effect of the backfill is more than 70%.
【学位授予单位】：辽宁工程技术大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U416.1

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