Expansive Rock Of Expansion-creep Coupling Test Reseach

Expansive rock has a dual characteristic of expansive and creep. The study on expansive and creep of expansive rock was carried out separately in the past, however, study on coupling of creep and expansive in expansive rock has not been evaluated so far at home and abroad. Expansive and creep of expansive rock have couplings and interaction. This paper has the original rock of tertiary mudstone in Nanning basin as expansive rock research object, and carries out lab tests of different initial water content, the different inflows, different load-on ways and different sample sizes to study expansive and creep coupling test curve and the variation laws of long-term strength in these conditions. The findings obtained are as follows:Initial water content has a significant iMPact on creep of expansive rock: High initial water content specimen have a large of creep deformation, and the first stage of creep was of long duration; CoMPared to the creep without expansive force, to add another loading, creep of water at both ends has significantly increased; this study present here only the range of long-term strength:(40.1%-57.0%) instantaneous intensity. When water intake is in different ways, instantaneous deformation and creep area increased with water absorption; Long-term strength without water values to80percent of instant strength.Under different load-on ways, when single-station loading on the basis of the force of expansion,Creep curve of water at both ends is as usual:First experienced the first stage of creep, and then proceed to the second stage of creep. Creep rates under different loads are different:the larger loads are, the higher rate is, When the load increases than the long-term strength, creep into the third stage. At the end of the first stage, when reduced to expansion force, single-station loading on the basis of the force of expansion,Creep curve of water at both ends is as usual too, And the long-term strength of low moisture content specimen of the water at both ends,same as creeping regularity of non-expansion coupling. When Specimen size is different, under single-level load, if loaded on the basis of the water at both ends and expansive force, large size specimen will enter the second stage of creep time behind the small size of the specimen. Through comprehensive analysis of expansive rock expansion under different conditions-coupling of creep test results.From above results, the following conclusion was drawn:long-term strength is greater than the expansion of expansive rock.