Influence of Loading Methods on Compression Modulus of Red Sandstone Soil Solidified with Biological Enzyme and Cement

There are various methods to test the modulus of cement-stabilized mixtures.The stiffness performance of cement-stabilized materials will be affected after adding biological enzymes.In order to systematically analyze the influence of loading conditions on the compression modulus of the red sandstone soil solidified with biological enzyme and cement，compressive modulus tests were conducted on the red sandstone soil solidified with biological enzyme and cement by using three static modulus test methods including monotonic loading method of middle section，stepwise loading and unloading method of top surface，and stepwise loading and unloading method of middle section，as well as dynamic modulus method of top surface and dynamic modulus method of middle section.The experimental results show that the load rate of dynamic modulus tests is much higher than that of static modulus tests due to the difference in loading frequency，which affects the comparability between dynamic modulus and static modulus.When the load level and load rate are equivalent，the resilience modulus of the stepwise loading and unloading method of middle section is relatively close to the elastic modulus of the monotonic loading method of middle section.Moreover，the monotonic loading method of middle section makes it easier to obtain representative moduli.