Widely-graded gravelly soil is composed of gravelly and clayey material in a certain proportion. It has the characteristics of low compressibility and high shear strength. At present
it is widely used as the core material for embankment dams and subgrade filling. Due to the low permeability of well-graded gravelly soil
the consolidation process is slow in conventional consolidated- drained (CD) triaxial tests
resulting in a long test period. In order to improve the efficiency of consolidation process
a quick triaxial CD test method with cylindrical sand core in the center of specimen is proposed in this paper. A comprehensive study on the influence of various factors on the quick triaxial CD test of well-graded gravelly soils is performed by changing types of sand cores
diameters of core sand cylinder and gravel contents. Results show that the proposed quick triaxial CD test method can effectively accelerate the consolidation process of the specimen
thus speeding up the whole test. Various factors including type of sand core
diameter of core sand cylinderand gravel content show different levels of influence on the speed of consolidation process and the stress-strain curve in the subsequent shearing stage. The smaller the diameter of the sand core is
the closer the test results are to those of specimens without sand cores.
Geotechnical Engineering Department, Nanjing Hydraulic Research Institute
Key Laboratory of Failure Mechanism and Safety Control Techniques of Earth-Rock Dam of the Ministry of Water Resources, Nanjing Hydraulic Research Institute