Study On The Failure Modes Of Reinforced Gravelly Soil Retaining Wall

Reinforced retaining wall has been widely used for its better seismic performance andgood economic efficiency in recent years, the theoretical and tests have made great progress.However, design and application of reinforced retaining wall are empirical in engineeringpractical, development of the theory behind the engineering practice. Disputes still exist inhow to determine whether the retaining wall reaches a critical failure state. There are lessstudy on determining the failure mode of reinforced retaining wall. This paper research deeplyand analyze systematically above-mentioned problems, it provides references for reinforcedretaining wall applying better in engineering practice.This thesis combines theory with engineer practice; numerical analysis is used to analyzestability of reinforced retaining wall based on strength reduction and gravity increase method.It determines the basis to judge whether the reinforced retaining wall destroyed, and verifiesits accuracy and rationality. Simultaneously, the author summarizes the failure modes ofreinforced retaining wall under a variety of conditions with different slope, reinforcementlength and spacing, and analyzes the destructive development progress and failure mechanism.The main results are as follows:1、The thesis combines with an instance of airport reinforced retaining wall with60mheight. Obtained that reinforced soil structure can significantly improve deformationconditions and restrain lateral deformation of soil. Meanwhile, it can reduce the differentialsettlement, improve the overall strength of soil and increase the stability of soil.2. The thesis base on strength reduction and gravity increase method, the critical statecriterion of no-reinforcement retaining wall is horizon displacement of slope point changerapidly; however, the plastic zone develops through from the slope foot to the slope top to bethe critical state criterion of reinforcement retaining wall.3. The thesis simulates a15m height reinforcement retaining wall, summarizes thefailure modes of reinforced retaining wall under a variety of conditions with different slope,reinforcement length and spacing. They are composite failure mode, and whole slip failuremode. The composite failure mode occurred when the length of reinforcement shortage,potential failure surface is upward from reinforced area at toe of wall into theno-reinforcement along the wall until beyond the reinforced area. The internal failure mode occurred in the case of longer length and larger spacing of reinforcement, the occurrence anddevelopment of shear failure is always in the reinforced area. The whole slip failure modeoccurred in the case of steep slope and smaller spacing of reinforcement, shear failure isupward along the wall while extending continuously to bedrock forming a continuous andthrough sliding surface and reinforced soil will slide with part of bedrock.4. The reasonable length and spacing of reinforcement have influence on the stability andeconomical efficiency of project, shorter reinforcement cannot play a reinforced role, butlonger reinforcement cannot full play to its tensile potentials and will cause waste; meanwhile,it is reasonable to reduce reinforced spacing in withstand larger force area of the lower part ofwall and increase in withstand smaller force area of the upper part of wall. Therefore, we cancontrol the lateral deformation and keep the stability better of the wall by pavingreinforcement with different length and sparse top-intensive bottom.