بررسي تجربي رفتار ديوار خاكي مسلح در مدل آزمايشگاهي كوچك مقياس

چكيده انگليسي :

AbstractReinforced soil technology has been extensively used during the last decades in theconstruction of embankments and retaining walls A large variety of reinforcing materialsemerged and have been developed for construction purposes including metal strips steelbars geosynthetics etc Full Scale experiments centrifugal and reduced scale laboratorymodel studies and field studies with the proper instrumentation of actual reinforced soilslope have been performed to provide a rational basis for design methods of reinforcingsystems The similitude requirements between the reduced scale model and the actualprototype were found to be difficult to formulate and practically impossible to verify Therefore the results of the laboratory model study cannot be extrapolated to provide adata base for empirical relationships between design parameters and system performanceof actual structures However these reduced scale models provided a very efficient rapidand economical research tool to investigate the failure mechanisms of the reinforced soilslopes In addition with more adequate instrumentation such models could be used inparametric study to evaluate available design approaches Some laboratory experiments were performed to observe the behavior of steepedreinforced soil slopes in small scale laboratory model under the plane strain conditions Reinforcements were made by a low strength paper strips and the loading on the soilsurface was done by step wised increments of dead weights By this small model effect ofshear resistance of soil number and width of reinforcement strips and width of loadingsurface are some subjects which have been studied A computational program has alsocompiled in Matlab in order to check the analytical interpretations of the Results Theeffect of the external loading and the tensile strength of the reinforcement strips have beenadded to the well known formula of Fellenius and Bishop by which the stability and therelevant amounts of safety factor were analyzed Based on the present study the following remarks could be concluded Failure conditions i e the geometric parameters of failure surface and the maximum tolerable load obtainedfrom the tests show very well compatibility between the test results and logical expectablebehavior The results indicated that the cross section of the failure surface is quite andclose to a circular arc in the cases corresponding to the external loads for all of the models Increasing the number or width of reinforcement strips width of loading surface distanceof loading from the edge and soil shear resistance all are on the side of increasing theamounts of tolerable external loads and reducing the radius of failure surface arc Theeffect of sidewall friction can be evaluated almost correctly for for considering in stabilitycomputations Simplified Fellenius s limit equilibrium formula is the most reliable equationfor the analyses regarding the failure conditions and factor of safety The modification forconsidering the effect of tensile strength of reinforcement and the sidewall friction inmodel tests results in excellent compatible and acceptable results It is very reliable toaccept that the peak friction angle of soil is mobilized during the the failure rather than theresidual

ميثاقي، عليرضا

بررسي تجربي رفتار ديوار خاكي مسلح در مدل آزمايشگاهي كوچك مقياس

ژئوسنتتيك ها , ديوارهاي حايل , روش فلنيوس