孔隙砂岩三轴压缩排水试验及地层失水沉降计算

发布时间：2018-04-15 03:20

本文选题：孔隙砂岩 + 压缩排水　；参考：《岩土力学》2017年S1期

【摘要】：针对在深厚白垩系和侏罗系孔隙砂岩含水层底部开采煤层是否引起上部含水层失水沉降问题,利用轴压恒定、变围压和孔隙水压的三轴压缩排水试验,研究不同粒径孔隙砂岩的轴向应变随孔隙水压降低的变化规律,以推导出一定厚度含水层的底部失水沉降计算公式。研究结果表明,(1)随着砂岩内的孔隙水压u降低,岩样会产生轴向压缩变形,并呈非线性增大,且砂岩粒径越大变形越大;(2)砂岩轴向排水变形ε_z与孔隙水压降△u以及初始孔隙水压u0有关,与围压σ3关系不大,且当u0不变、△u越大以及△u不变、u0越小时,所产生的轴向应变ε_z越大;(3)利用ε_z、△u、u0三者间的拟合函数所推导出的砂岩含水层失水沉降计算公式,在一定范围内能够进行多含水层失水沉降计算,为含水孔隙砂岩地层失水沉降计算提供一种新方法。
[Abstract]:In view of the problem of whether the coal seams at the bottom of deep Cretaceous and Jurassic porous sandstone aquifers will cause the water loss and settlement of the upper aquifer, a triaxial compression drainage test with constant axial pressure and varying confining pressure and pore water pressure is used.The variation of axial strain with the decrease of pore water pressure of porous sandstone with different diameter is studied, and the formula for calculating the loss of water at the bottom of aquifer with certain thickness is deduced.The results show that with the decrease of pore water pressure u in sandstone, the rock sample will produce axial compression deformation and increase in nonlinearity.The larger the grain size of sandstone is, the larger the deformation is.) the axial drainage deformation 蔚 _ (Z) of sandstone is related to pore water pressure drop u and initial pore water pressure u _ 0, but not to confining pressure 蟽 _ 3, and when u _ 0 is constant, u is larger and u _ (0) is less.The larger the axial strain 蔚 Z is generated, the greater the axial strain 蔚 Z is.) the formula for calculating the loss of water in sandstone aquifer can be obtained by using the fitting function between 蔚 z and uzu 0, and can be used to calculate the water loss settlement of multi-aquifer within a certain range.It provides a new method for calculation of water loss settlement in porous sandstone formation.
【作者单位】：北京交通大学土木建筑工程学院;北京科技大学土木与环境工程学院;
【基金】：中央高校基本科研业务费专项资金项目(No.C15JB00200) 国家自然科学基金重点项目(No.71631007)~~
【分类号】：TD74

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