Experimental Study On The Static Performance Of The Hybrid Reinforced Soil Retaining Wall With The Length Of Prestressed Reinforcement

The reinforcement material in the traditional reinforced soil is a kind of passive constraint,and the requirement of the filler is higher,that's why the application range of reinforced soil technology is limited.Unbonded prestressed reinforced soil technology,aiming at improving the shortages existing in the traditional reinforced soil,is a new reinforced soil technology.The new reinforced soil structure composed of filler,wall panel,side slab,reinforcement and anchorage,is to actively constraint filler by prestressed reinforcement,which can reduce requirements and the vertical deformation of the filler,also can increase the stability of the structure.The length of prestressed reinforcement is one of the important factors that affect the mechanical properties and the stability of hybrid reinforced retaining wall which used the application of unbounded prestressed reinforced soil technique.In order to study the effect of the length of prestressd reinforcement on the static performance of hybrid reinforced retaining walls,a new scale model test of increasing density was used to design three conditions with the length of prestressed reinforcement as variables,and the following research results are obtained:(1)The new scale model test of increasing density can meet the equivalent of stress field with model and prototype at the conventional gravity field,solves the problem of similarity ratio.(2)The existence of pre-tension can make the panel-reinforcement-filler to form a whole system,the system has a higher carrying capacity and resistance to deformation capacity which can significantly reduce the displacement of the wall panel and the vertical settlement of the filler.The active constraint effect by prestressed reinforcement is obvious,but the glass fiber grid can still play a passive role in the filler.(3)The horizontal earth pressure on the back of the wall panel and the side slab are not related to the length of the prestressed reinforcement.The horizontal earth pressure of the side slab is about 1/2 of Rankine's active earth pressure,the effect of filler on the horizontal load of reinforced body is obviously reduced.(4)After the pre-tension is applied,the horizontal earth pressure in reinforcement range presents "two ends big,middle small" state;the ratio of the side slab in front of the horizontal earth pressure increment and wall panel back horizontal soil pressure increment is a fixed value,which is not related to the length of the prestressed reinforcement but the pre-tension,the calculation formula of the fixed value is put forward;a function of two variables,the filler depth and the pre-tension,used for the calculation of horizontal earth pressure is put forward;the middle of unbounded prestressed reinforcement is "necking zone" of the development of stress route,the horizontal earth pressure increment is closely related to the wall panel back horizontal soil pressure increment,the increment of horizontal earth pressure in the middle part decreases linearly with the length of the reinforcement due to the decrease of stress-transfer.