饱和岩石对平均应力和动载应力振幅的响应

第27卷 第1期

岩石力学与工程学报 V ol.27 No.1

2008年1月 Chinese Journal of Rock Mechanics and Engineering Jan.，2008

收稿日期：2007–05–08；修回日期：2007–07–28 基金项目：国家自然科学基金资助项目(40474065)

作者简介：李 廷(1973–)，男，博士，1995年毕业于河北建筑科技学院矿井建设专业，现为博士后、高级工程师，主要从事岩土工程和孔隙介质波动理论方面的研究工作。E-mail ：litingearl@

饱和岩石对平均应力和动载应力振幅的响应

李 廷，杜 赟，宛新林，席道瑛

(中国科学技术大学 地球和空间科学学院，安徽 合肥 230026)

摘要：在单轴循环加载实验中不断改变平均应力和正弦波应力振幅的实验条件下，研究饱和砂岩和大理岩的动态响应。研究结果表明，随平均应力增大，弹性模量增大，泊松比先增大后减小，滞回圈面积减小，衰减量减小。平均应力和动载应力振幅同时改变时，对动态响应影响最大；其次是平均应力不变而只改变正弦波应力振幅时，对应变、弹性模量、泊松比和衰减量的影响都很大，比改变平均应力对饱和岩石的动态响应显著得多。对环境介质的腐蚀作用进行探讨。由于水的应力腐蚀作用，饱水砂岩比饱油砂岩的衰减量增长1倍，动态响应很明显。由于大理岩结构致密，孔隙度仅有1%

左右，导致砂岩的应力腐蚀作用明显大于大理岩。该研究成果对地震和地质

灾害的防治是很有意义的。

关键词：岩石力学；饱和岩石；平均应力；正弦波应力振幅；应力腐蚀

中图分类号：TU 45 文献标识码：A 文章编号：1000–6915(2008)01–0161–08

RESPONSES OF SATURATED ROCKS TO MEAN STRESS AND DYNAMIC

STRESS AMPLITUDE

LI Ting ，DU Yun ，WAN Xinlin ，XI Daoying

(School of Earth and Space Sciences ，University of Science and Technology of China ，Hefei ，Anhui 230026，China )

Abstract ：By shifting the mean stress and the sine wave stress amplitude ，uniaxial cyclic experiments were performed to study the dynamic response of fluid-saturated sandstones and marbles. The experimental results show that the modulus increases as the mean stress increases. As the mean stress increases ，the Poisson ′s ratio increases at first ，and then decreases. The area of hysteresis loop decreases ，and the attenuation decreases too. When shifting both the mean stress and the dynamic stress amplitude ，the influence on dynamic response is the most intensive. The influence on dynamic response by shifting only the dynamic stress amplitude and remaining the mean stress unchanged is also very intensive. The influence on dynamic response by shifting only the mean stress is not much intensive. Stress corrosion on surrounding media has been discussed. Because of the stress corrosion of water ，the attenuation of water-saturated sandstones is twice as that of oil-saturated sandstones ；and the dynamic response of water-saturated sandstones is clearer than that of oil-saturated sandstones. Because marbles are more compacted than sandstones and the porosity is only about 1%，the stress corrosion is more serious in sandstones than that in marble. This research is very significant to the alleviation and control of seismic and geological disasters.

Key words ：rock mechanics ；saturated rocks ；mean stress ；sine wave stress amplitude ；stress corrosion

1 引 言

岩石由许多各种各样的矿物颗粒组成，相邻颗

粒紧密接触构成了固体骨架，颗粒间的裂纹和微结构边界的存在是不可避免的。作为这种多组分非均匀的岩石材料，必然会存在大量各式各样的细观结构[1

，2]

(裂纹、节理、孔洞等)，导致岩石的非线性弹