作者：熊魂, 付小敏, 王从颜, 宾婷婷, 沈忠, 黄兴建
作者单位：成都理工大学地质灾害防治与地质环境保护国家重点实验室, 四川 成都 610059
关键词：岩石力学;三轴加、卸载;弹性模量;塑性环
摘要：
对取自某油田深部含油气地层的砂岩,利用MTS815岩石力学测试系统,对砂岩进行不同围压条件下的加、卸载试验.研究围压对砂岩变形特征的影响,探讨砂岩在加、卸载过程中应力-应变曲线的变化规律,以及对弹性模量的影响程度.结果表明:三轴加、卸载的应力-应变曲线不重合,形成一个开口的塑性环;在不同的围压条件下,加、卸载阶段的弹性模量不相等,卸载时的弹性模量高于加载时的弹性模量;在保持轴向应力不变的情况下,随着围压的增加,加载阶段弹性模量逐渐增大,围压在40MPa时,弹性模量达到最大值,随后弹性模量趋于平缓甚至有下降的趋势.
Experimental study of sandstone under different confining pressure deformation characteristics
XIONG Hun, FU Xiaomin, WANG Congyan, BIN Tingting, SHEN Zhong, HUANG Xingjian
State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu Universityof Technology, Chengdu 610059, China
Abstract: Taken from a hydrocarbon oil in deep sandstone formations using MTS 815 rock mechanics testing system, were added to the sandstone under different confining pressure conditions, unloading tests. Research confining pressure on the deformation characteristics of sandstone, sandstone explore the loading and unloading process, the variation of the stress-strain curve, and the degree of influence on the elastic modulus. The results showed that: triaxial add stress to uninstall-strain curves do not overlap, forming an opening in the plastic ring. Under different confining pressure, the elastic modulus of loading, unloading stages are not equal, The elastic modulus of loading stage is higher than that of loading stage. In keeping the axial stress is constant, with the increase of confining pressure, loading phase elastic modulus increases, the confining pressure at 40 MPa, the elastic modulus reaches a maximum, then the elastic modulus of the trend leveling off or even declining.
Keywords: rock mechanics;triaxial loading and unloading;modulus of elasticit;plastic ring
2015, 41(3): 113-116,120 收稿日期: 2014-9-12;收到修改稿日期: 2014-11-17
基金项目: 国家自然科学基金项目(41272321)
作者简介: 熊魂(1989-),男,湖北荆州市人,硕士研究生,专业方向为建筑与土木工程.
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