Numerical Simulation And Design Software Development Of High Reinforced Gravelly Soil Retaining Wall

With the rapid development of the national economy, to meet the project needs, thedomestic works developing toward the direction that the scale continues to expand, buildingterrain conditions increasingly complex. In order to minimize the project occupancy area,more and more large projects were selected as high and steep slope design, and many of themwere chose to build at the mountainous terrain area which affects the residents relatively smalland with relatively small land value. The construction of reinforced retaining wall is soft,building terrain is small, easy construction, with good seismic performance and attractiveappearance, coupled with the package designing of reinforced structure, on which plants cangrow, appears recently. It makes reinforced soil structure both to prevent the rain erosion, andbeautify the environment. It can be seen that the reinforced earth structure in the futureconstruction projects will have a good development prospects.This thesis is based on an airport project of southern China, by means of numericalanalysis, using the ADINA and GEO-Studio software to simulate, with selection of suitablematerial for practical engineering constitutive model by analysis the site survey geologicaldata, triaxial tests of the filler and reinforced triaxial tests and geogrid performanceparameters. According to the actual terrain data of the project to establish three-dimensionalcomputational model to calculate the displacement and deformation of the reinforcedretaining wall, and compared with the actual monitoring data, verify the rationality of thematerial parameters. On this basis, the two-dimensional model of the typical section of theproject were established, and commonly used design models which have different slope anglein a retaining wall project were established, according calculation results, such as deformationand failure forms of these computational model, the core source codes of design softwarewere typed to provide a supply for reinforced retaining wall designing and calculation.The main achievements of this article as following:(1) Calculation results of three-dimensional model of typical project indicate that: themain settlement occurred at the rear fill settlement of the retaining wall and the maximum isapproximately30cm, which is basically the same with the monitored value of actual project settlement. The horizontal displacement of the lower part of the wall is larger than the otherparts of the wall and the plastic distribution occurred at the bottom of the retaining wall, andall the calculation results are the same as the three-dimensional computational result, whichillustrates that using rebar element to simulate geogrid material can meet the projectrequirements;(2) Reinforced calculations and analysis show that the reinforcement influences theplastic zone distribution of the retaining wall. The reinforcement can control the developingspeed of plastic zone which along the vertical direction to the top of the wall, and will changethe plastic zone morphology of the soil from the ‘thin’ shape of unreinforced soil into‘chunky’ shape;(3) Different angles of a retaining wall analysis illustrate that reinforcement will controlthe horizontal displacement of the retaining wall, and can play a coordination role of soildeformation. When only gravity condition was calculated, the potential of reinforcementusually does not fully display and control of the deformation of the wall is not obvious, andonly when the slope instability and the potential will be fully played;(4) The analysis results of two-dimensional calculation of typical project and single stageretaining wall indicate that, in normal working condition, the deformation coordination effectof reinforcement was not obvious in the value of deformation of the wall, while on the changein the location of the maximum settlement was obvious. After the laying of reinforcement, themaximum settlement location of the wall move along the inside wall direction, so prone tosliding soil expand with smaller slip trend. As to horizontal displacement control effect, themaximum displacement at wall face usually located at1/3of wall height.(5) Sigma/w and Slope/w joint calculation results are smaller when compared with finiteelement strength reduction, and there is a certain safety margin. And the joint calculationresults can be used as the calculation starting point to save computation time;(6) Obtained by comparing the analysis results of Sigma/w and Slope/w combinationcalculation, strength reduction calculation which does or does not take reinforcement pull offinto account indicate that: the calculation method which does not take reinforcement pull offinto account does not apply to determine the potential slip surface form. While the calculationmethod which takes reinforcement pull off into account can simulate the reinforcement pulloff and the final failure surface of real project, it can reflect the actual failure mode ofreinforced retaining wall more realistic and reasonable and the results are with little differencewhen comparing with Sigma/w and Slope/w combination calculation. Comprehensive analysis of the results indicates that, the reinforcement will control thehorizontal displacement, coordinate the soil deformation, and control the longitudinal speedof plastic zone developing, which is conducive to the slope safety; when soil deformation issmall the reinforcement coordinate ability is not obvious, while it can easy to find out whenthe retaining wall become imbalance; the limit equilibrium method and the finite elementmethod coupled calculation results can be used as finite element strength reduction calculatestarting point, thus saving computing time; the calculated results of FEM strength reduction,which take reinforcement pull off into account, are more appropriately for real reinforcedretaining wall project, and the calculated safe and stability factors closed to the resultscalculated by Sigma/w and Slope/w combined method.