恒湿环境下不同含水饱和度砂岩制备方法及压缩试验  

Preparation Method and Compression Test of Sandstone with Different Water Saturation Under Constant Humidity Environment

作　　者：付腾飞 朱德福[2] FU Tengfei;ZHU Defu(School of Electric Power,Civil Engineering and Architecture,Shanxi University,Taiyuan 030031,Shanxi,China;Key Laboratory of In-situ Property Improving Mining of Ministry of Education,Taiyuan University of Technology,Taiyuan 030024,Shanxi,China)

机构地区：[1]山西大学电力与建筑学院,山西太原030031 [2]太原理工大学原位改性采矿教育部重点实验室,山西太原030024

出　　处：《黄金科学技术》2024年第2期280-289,共10页Gold Science and Technology

基　　金：国家自然科学基金项目“浅埋非充分垮落区下条-柱充填开采覆岩结构协调变形机制”(编号:52174124)和“浅埋非充分垮落区下开采覆岩结构联动失稳机理”(编号:51904200)联合资助

摘　　要：针对目前制备不同含水饱和度岩石试样存在的精度低和试样内部含水分布不均匀等问题,基于渗透技术和化学热力学原理,设计了一种恒湿环境下不同含水饱和度岩石试样制备装置,并通过核磁共振成像实验验证了该装置精确制备水分均匀分布岩石试样的合理性。同时,利用该装置开展了不同含水饱和度条件下砂岩常应变率压缩试验。结果表明:砂岩的单轴抗压强度和弹性模量均随着含水饱和度的增加而降低,随着围压的增大,试样砂岩压密阶段减弱,试样的变形经历弹脆性—弹塑性—应变硬化的过程。研究结果为不同含水饱和度岩石试样的精确制备提供了新的方法和思路。In view of the low accuracy and uneven water distribution of water content in rock samples with different water saturations,a preparation method of rock samples with different water saturations and uniform distribution of water content was proposed based on the principle of osmotic technology and chemical thermodynamics.The basic principle consists of two parts:One is to control the concentration and molecular weight size of polyethylene glycol(PEG)in organic solution,so as to precisely control the matrix suction values of the solution water and water in the sample to determine the final water saturation of the sample.The other is to control the type of supersaturated solution placed in the constant humidity environment of the rock sample,so as to precisely control the chemical potentials of the component water when the total weight of the sample is stable,and the final water saturation of the sample is determined.The water saturation of rock samples prepared by this mothed are qualified samples with uniform saturation distribution.The water rationality of the method for accurately preparing rock samples with uniform water saturation distribution was also verified by nuclear magnetic resonance imaging(NMRI)experiments.Meanwhile,a device is designed independently to prepare rock samples with different saturations under constant humidity environment,and the constant strain rate compression test of sandstone under different saturation conditions was carried out by using the device.The test results show that the uniaxial compressive strength and elastic modulus of sandstone decreases with the increase of water saturation.After the peak,the post-peak stress decline slows and the brittleness of the sample decreases with the increase of water saturation.With the increase of confining pressure,the compaction stage of sandstone sample is weakened,and the deformation of the sample undergoes the process of elastic-brittle→elastic-plastic→strain hardening.The results of the study provide new methods and ideas for the acc

关 键 词：恒湿环境 饱和度 渗透技术 化学热力学 制备装置 砂岩试样 

分 类 号：TU45[建筑科学—岩土工程]