巨厚新近系底部地层特征数值模拟研究

Study on Numerical Simulation of Huge Thick Neogene Floor Strata Features

巨野煤田龙固煤矿上覆第四系和新近系松散层厚度达600 m以上,新近系松散层底部由黏土层、砂层相间沉积形成。为了研究新近系底部地层结构特征,加深对这种特殊类型土体下开采覆岩移动规律的认识,运用FLAC3D软件,对不同黏土固结程度、新近系底部岩性组合结构进行数值模拟分析,对比不同结构的下沉值、下沉速率和塑性区破坏状态。结果表明,固结程度低的黏土最大下沉量比固结程度高的黏土高约27.8%;低固结黏土塑性区发育最大高度距煤层顶板105 m,高固结黏土塑性区发育最大高度距煤层顶板80 m,获得了巨厚新近系底部地层特征。

The thickness of the overlaid Quaternary System and Neogene System unconsolidated layers in Longgu Mine of Juye Coalfield was over 600 m.The bottom of Neogene System unconsolidated layer was sedimentary and formed with clay and sandstone.In order to study the structure features of the strata at the bottom of Neogene System and to further understand the overburden strata movement law of the mining under the special type soil mass,the FLAC3D software was applied to the numerical simulation analysis which was conducted on the different clay consolidation degrees and the combined structure of the lithology at the bottom of the Neogene System.A comparison was conducted on the subsidence value of the different structure,the subsidence rate and the failure state of the plastic zone.The result showed that a max subsidence value of the clay with a low consolidation degree would be 27.8%higher than the clay with a high consolidation degree.A max height distance developed in the plastic zone of the clay with a low consolidation degree was 105 m to the seam roof and a max height distance developed in the plastic zone of the clay with a high consolidation was 80 m to the seam roof.The strata features at the bottom of the giant thick Neogene System were obtained.