分级加载条件下红层软岩蠕变特性试验研究  

STUDY ON CREEP PROPERTIES OF RED-BED SOFT ROCK UNDER STEP LOAD

作　　者：谌文武[1,2] 原鹏博[1,2] 刘小伟[1,2] 

机构地区：[1]西部灾害与环境力学教育部重点实验室,甘肃兰州730000 [2]兰州大学土木工程与力学学院,甘肃兰州730000

出　　处：《岩石力学与工程学报》2009年第A01期3076-3081,共6页Chinese Journal of Rock Mechanics and Engineering

基　　金：西部交通科技建设项目(200231800026);西部交通科技建设项目(200231800036)

摘　　要：岩石的蠕变特性是岩石类材料的重要力学性质之一,很大程度上控制着岩体工程的稳定性。本文采用CSS–44100型电子伺服万能试验机在分级加载条件下对甘肃引洮输水工程7#试验平硐红层软岩进行了一系列单轴压缩蠕变试验。通过对试验数据的整理与分析,发现红层软岩存在显著的蠕变特性,符合伯格斯模型(Burgersmodel),并求取了不同应力水平下的蠕变参数。通过测定试样含水率,研究含水率对红层软岩强度和蠕变特性的影响。发现含水率越高,抗压强度越低,蠕变量越大,蠕变率也越大,达到稳定的时间也越长。试验结果表明,红层软岩蠕变试验曲线与理论曲线基本吻合,伯格斯模型(Burgersmodel)能较好的描述红层软岩的蠕变特性。Creep characteristic is one of the most important mechanical characteristics of rock. It controls the stability of rock engineering. Under step load condition, the creep test of red-bed soft rock which was collected in the seventh tunnel of Yintao water transmission engineering in Gansu is performed by using the CSS-44100 electronic servo testing machine. Based on scientific interpretation and analysis of test data, red-bed soft rock has remarkable creep characteristics and Burgers creep model can be applied to characterize the creep of red-bed soft rock. The effect of water content upon strength and creep characteristic are studied it shows that instantaneous strength decreases with increasing of water content. The higher the water content is, the more creep deformation and the time that need reaching steady state and the bigger the rate of creep are. The test results show that the creep testing curves of red-bed soft rock are coincident well with the theoretic curves and the Burgers creep model can be applied to characterize the creep properties of red-bed soft rock.

关 键 词：岩石力学 红层软岩 蠕变 分级加载 伯格斯模型 含水率 

分 类 号：TU45[建筑科学—岩土工程]