Experimental research on strength of five-axis cement-soil mixed piles

Based on a review of disadvantages of the construction techniques for cement-soil mixed piles in China, a new construction method called five-axis mixed pile method is developed. This new method has low cost, environmental pollution, short construction period and high efficiency. In order to investigate the improvement effect of five-axis mixed piles for soft ground in excavation engineering, comparison tests between five-axis mixed piles and biaxial, triaxial mixed piles are conducted in the same geological field. Through the unconfined compression tests on coring samples taken from cement-soil mixed piles, the test results show that the strength of the triaxial mixed piles is low and much more discrete, the strength of the biaxial mixed piles is better in every layer, but the discreteness of strength values greatly changes at different ages. However, the five-axis mixed piles with higher strength and low discrete behavior may have a good population and application value in the future.