含水松散层固结对地表沉陷影响的数值分析

Numerical analysis of water-bearing alluvium consolidation influence on surface subsidence

为了研究含水松散层固结对地表沉陷的影响,基于固结沉降量对预计参数确定的重要性,分析了影响含水层固结的因素,包括渗透系数、松散层厚度、采动程度和采煤方法.在分析现场实测资料的基础上,采用FLAC3D流-固耦合计算的方法,对覆岩内部位移场和渗流场进行了分析,研究了含水层固结压缩对地表沉降的影响.结果表明不考虑冲积层含水时,地面最大沉陷值为1220mm,考虑冲积层含水时,最大沉陷值为1306mm,下沉量增加86mm.地面沉陷盆地的外缘,沉陷量显著增加,增加量为160mm,最大沉降增加量为7%;走向方向和倾向方向松散层含水条件下均比不含水条件下水平移动量大,走向方向最大相差122 mm,倾向最大相差105 mm.

In order to study water-bearing alluvium consolidation＇s influence on surface subsidence,the factors influencing water-bearing consolidation,including seepage factor,alluvium thickness,mining degree and mining methods were analyzed based on the importance of consolidation subsidence to determining prediction parameters.Based on analyzing field surveying datum,overburden inner displacement field and seepage field were analyzed by the method of FLAC3D fluid-mechanical interaction calculation.The influence of water-bearing alluvium consolidation on surface subsidence was researched.It is shown that when alluvium does not bear water,maximum surface subsidence is 1 220 mm.However,when alluvium bears water,maximum surface subsidence is 1 306 mm and increment is 86 mm.At the brim of subsidence basin,incremental subsidence is obvious reaching 160 mm and maximum increment percentage is 7%.Further more,for strike and dip of face horizontal movement of water-bearing alluvium was larger than that of no water-bearing alluvium.Maximum difference for strike of face was 122 mm and 105 mm for dip.