Experimental research on soil water characteristic curve of parallel specimens and its influence on mechanical behavior

The drying tests on eight triaxial specimens with the same remolding condition are carried out for soil water characteristic curve (SWCC). The differences of SWCC are compared. The unconfined compressive strength tests on seven effective specimens after SWCC tests are carried out. The relationships of shear force-shear displacement, peak strength-saturation degree, and saturation degree-time are investigated for analyzing the mechanical behavior of specimens. The results show that there are significant differences for SWCC in a certain range of matric suction, and with the increase of matrix suction SWCC will tend to be uniform. After SWCCs tests are finished, differences of equilibrium saturation degree between parallel specimens are very small because of high matrix suction, and then the peak strength and equilibrium saturation degree do not have necessary connection. At a certain range of matric suction, the specimens with similar curves of saturation degree versus time have approximate mechanical behavior. Because the pore ranges corresponding to this range of matric suction play a leading role in the specimens, the uniformity of specimens will be studied by the corresponding curves of saturation degree versus time.