| National development needs energy to promote,China’s current stage of rapid development of various industries,the demand for energy is increasingly large,and mines are the main object to provide energy;with the continuous supply of energy,the development of mines more and more vigorous,in the development process produces a large number of mine solid waste.For example,fly ash is a solid waste discharged from the burning of coal,and slag is also an industrial solid waste;at the same time,in the construction of the project,pile foundations are essential,but it is difficult to avoid soft soil geological problems during the construction process,and the foundation needs to be cured before construction,this preparation work makes the construction period drag on and costs increase.Static drilling root pile is a new combination of prefabricated pile and hydraulic soil combination of a new combination of pile foundation,less pollution,less hazardous;the current research on the bearing performance of static drilling root pile is mainly for ordinary hydraulic soil,but the bearing performance of solid waste early strength hydraulic soil coupled with static drilling root pile research is less.In view of the above problems,this thesis mainly adopts fly ash mineral powder to make curing agent and applies it to the soil around the pile of static drilled root pile,analyses its bearing mechanism on static drilled root pile according to the test and simulation results,and carries out field engineering application of static drilled root pile.The main research contents and findings of this thesis are as follows:（1）Mineral powder alone was used to replace part of the cement and gypsum powder was used as the exciter;by conducting the unconfined compressive strength test,it was clear that the strength of the specimens made was the highest when the fixed gypsum powder admixture ratio was 5%and the ratio of cement to mineral powder was4:6;fly ash was used to replace part of the mineral powder for the optimisation test,and the test showed that the strength of the specimens made reached the highest when the ratio of fly ash to mineral powder was 1:9.The parameters such as cohesion and internal friction angle of the specimens made of fly ash mineral curing agent were then measured by direct shear test to provide data for later tests.（2）The interfacial friction characteristics of precast pile-solid waste early-strength hydroclay and solid waste early-strength hydroclay-sand were investigated separately,and it was concluded from the interfacial shear test that in the precast pile-solid waste early-strength hydroclay interface,the interfacial ultimate lateral friction resistance is positively related to the strength of solid waste early-strength hydroclay,and its interfacial properties are mainly influenced by the nature of solid waste early-strength hydroclay.In the solid waste early-strength hydroclay-sand interface.Although the ultimate lateral resistance of the interface increased with the age of maintenance,the increase in ultimate lateral resistance was small;relative to the pure cement blank control group the lateral resistance increased at all ages,but not by much.The ultimate lateral resistance at the interface between the solid waste early-strength cement and the sand was influenced by the nature of the sand because the strength of the solid waste early-strength cement was significantly greater than the strength of the sand.（3）ABAQUS software was applied to simulate the compressive load bearing performance of the static drilled root pile under the action of the hydroclay around the solid waste early strength pile,and the simulation results showed that the cohesive force,internal friction angle and elastic modulus of the hydroclay around the solid waste early strength pile had little influence on the compressive load bearing performance of the static drilled root pile;while increasing the friction coefficient of the contact surface of the solid waste early strength hydroclay-soil and increasing the diameter of the borehole could significantly improve the compressive load bearing performance of the static drilled root pile.The compressive load-bearing performance of the piles can be significantly improved by increasing the friction coefficient of the soil-soil contact surface and increasing the diameter of the borehole.（4）Field static load test of solid waste early strength cement on static drilled root pile,the test results show that the application of different solid waste early-strength hydraulic soils has different effects on the load-bearing performance of the static drilled root piles,and the sinkage of the C40M54FA6P5（2#test pile）group is the smallest at11.93mm under the same load condition;the test results prove that the effect of the fly ash mineral powder curing agent studied in this thesis is better than that of the pure cement curing agent.The application of fly ash mineral curing agent to actual projects can not only save a lot of costs,but also reduce the pollution problem of tailings and fly ash to the environment,which is in line with the national sustainable development strategy,and can also promote the construction of green mines. |
