Non-Darcy flow seepage characteristics of saturated broken rocks under compression with lateral constraint

sing an MTS816.03 test system and self-designed seepage apparatus,seepage tests of saturated broken rocks were conducted,and the influence of lithology,axial stress,grain size distribution and loading rate on seepage characteristics was analyzed.The results show that:(1) Under the same axial stress(12 MPa)the permeability of different lithologic samples increases in the order:gangue < mudstone < sand stone < limestone.The permeability of gangue is 3 magnitudes lower than that of limestone.The absolute value of the non-Darcy coefficient β increases in the order:limestone < sandstone < mudstone < gangue The non-Darcy coefficient β of limestone,which is positive,is 5 magnitudes lower than that of gangue.(2)With increasing axial stress,the permeability of saturated broken sandstone decreases,and the absolute value of the non-Darcy coefficient β increases.After the axial stress exceeds 12 MPa,the curves of perme ability and non-Darcy coefficient β all tend to be stable.(3) With increasing Talbol power exponent,the permeability increases,and the absolute value of the non-Darcy coefficient β decreases.(4) With increas ing loading,the permeability increases,and the absolute value of the non-Darcy coefficient β decreases When the loading rate is 0.5 kN/s,the non-Darcy coefficient β is positive.

外贴智能骨料隔墙连接构件工作性能研究

为了降低轻质隔墙接缝灌浆开裂风险,设计研究新型轻质隔墙连接构件。试验设置两组基于隔墙连接装置的拉伸构件,改变连接装置预应力水平,研究连接构件在荷载作用下开裂荷载及开裂后工作性能。采用外贴智能骨料检测构件开裂,研究连接区开裂及损伤问题。采用信号小波包能量分析方法,检测隔墙连接区浆体开裂及极限拉伸破坏,基于检测结果得出连接区灌浆开裂预警指标,提出连接装置贡献指数。结果表明,连接装置能够起到阻裂作用;连接装置预应力增加能够提高开裂荷载;贡献指数大于等于0.3能够有效起到阻裂作用;界面开裂引起检测信号幅值和损伤指数下降;外贴智能骨料能够检测截面开裂及损伤发展过程,通过合理指标选择,可以预警浆体开裂和最终破坏。