Drainage Test And Simulation Study Of High Suction Geotextile In Subgrade

Diseases caused by excessive moisture are one of the main reasons for premature road damage.Traditional drainage methods such as gravel layer and drainage geotextiles are only suitable for draining water in high saturation state.Because of the suction of unsaturated soil,it is difficult for traditional drainage methods to drain water.This paper introduces a new type of drainage method,which uses capillary suction and evaporation to reduce the moisture content of roadbed.This paper emphatically introduces the material composition and basic performance index of high suction geotextiles,the process mechanism of reducing water content of unsaturated pavement system by high suction geotextiles,the experimental study on drainage of high suction geotextiles subgrade,and the numerical simulation of Subgrade under the action of drainage layer of geosynthetics.The main research results are as follows:1.The high-suction geotextile has different drainage effects on different subgrade filling materials,and the drainage effect in coarse-grained sand subgrade is more obvious than the powder clay subgrade.2.The high-suction geotextile has better drainage effect than the traditional drainage material.In the powder clay test chamber,the high-suction geotextile reduces the moisture content of the observation point from 44% to 29.6%,and the ordinary short-fiber needlepunched geotextile will have the moisture content of the observation point from 44 % decreased to 39%,and the sand barrier reduced the moisture content of the observation point from 44% to 37.3%.The high-suction geotextile has obvious drainage effect compared with the latter two.3.High-suction geotextiles can play a certain role in blocking the upward invasion of capillary water in the lower layer of subgrade.In the test of adsorption of capillary water by geotextiles,the capillary water is transmitted to the outside of subgrade by high-suction geotextiles.4.Finite element simulation can effectively simulate the unsaturated seepage of subgrade without water source.Saturation increases with the increase of subgrade depth,and the saturation of both sides of subgrade is close to the same.This paper describes the subgrade drainage performance of high-suction geosynthetics,which can provide a new method for improving pavement performance.which is of guiding significance for the design,construction and maintenance of roads.