厚松散表土层条件下南沱河堤坝开采沉陷预测

Mining Subsidence Prediction of Nantuo River Bank Under Condition of Thick and Unconsolidated Overburden

为了安全地回采河堤下煤层,必须对河堤采动沉陷规律进行预测分析。根据百善煤矿6124工作面地质采矿条件,分别采用概率积分法和FLAC3D数值模拟,对厚松散表土层条件下的南沱河南堤进行了开采沉陷预测,并对堤体裂缝发育程度进行了研究。结果表明:概率积分法预计效果优于FLAC3D数值模拟预计,概率积分法从水平变形的临界值反映了河堤裂缝的范围,在厚松散层条件下,上山方向的河堤临界裂缝变形值应取+2 mm/m,下山方向的河堤临界裂缝变形值取+5mm/m。同时研究证明,受百善煤矿6124工作面开采影响的南沱河南堤段为不安全河堤,必须采取加固防渗安全措施才能确保堤防安全。

In order to safely mining the coal resources under the river bank, it is necessary to predict and analyze the subsidence law of the river bank. Based on the geological mining conditions of the 6124 coal mining face in Baishan Mine, the probability integral method and the FLAC3D numerical simulation were applied to predict the mining subsidence of the Nantuo River Bank under the condition of the thick and unconsolidated overburden and also applied to study the crack development degree of the bank. The results showed that the pre- diction results of the probability integral method was better than the prediction of the FLAC3D numerical simulation. The probability inte- gral method could reflect the range of the river bank cracking from the critical value of the horizontal deformation. Under the condition of thick and unconsolidated overburden, the critical crack and deformation value of the river bank under and along the mine rise mining di- rection should be selected as ＋ 2 mm/m and the critical crack and deformation value of the river bank under and along the mine dip mining direction should be selected as ＋ 5 mm/m, The study showed that the south river bank of the Nantuo River influenced by the min- ing of the 6124 coal mining face in Baishan Mine would be the unsafe river bank. The safety measures of the reinforcement and water leak- age prevention should be taken in order to ensure the safety of the river bank.