Optimal Design Of Assembly Retaining Wall With A Relieving Shelf

With the development of industrialization,assembly structures are being popularized because of its advantages of factory production,high construction quality,short construction period and little environmental pollution.Because of its unique structure form,the mechanical behavior of the retaining wall with a relieving shelf is optimized and the amount of wall material is saved,the improvement of construction efficiency has been paid more and more attention.Therefore,in order to give full play to the application value of the assembly retaining wall,with the support of the National Nature Science Foundation of China(No.51579119)and Jianhua Building Materials Investment Co.Ltd(original Jianhua pipe piles Investment Co.Ltd),this paper designs an assembly retaining wall with a relieving shelf based on the characteristics of lateral earth pressure.And the theoretical and experimental studies on key connection nodes and optimization of structural parameters are carried out.The following works are done in this paper and some conclusions are drawn:Firstly,taking the connection node between the panel and the bottom plate as the research object,the connection form of post-poured concrete is put forward.And the horizontal loading model test and numerical simulation are used to carry out the structure horizontal bearing of the retaining wall with a relieving shelf from the cracking of the retaining wall,the structural deformation,the stress distribution of the concrete surface and the force performance of the post-poured node.The results show that precast elements of the assembly retaining wall connected by post-pouring form can achieve the same bearing capacity of the global cast-in-site retaining wall.The node which is designed by larger section and poured by higher grade concrete can reduce the degree of stress concentration effectively,enhanced connection joint strength.And it can avoid the joint damaged before the retaining wall.Secondly,in order to avoid the problem that the important node of the retaining wall as the assembly node leads to the weakness of the connection and the easy destruction,the connection node between the prefabricated components is moved to the bottom plate,and the tenon and angle are added in the node.The relieving shelf and the tenon are proved by the theoretical calculation and the numerical simulation that they can greatly improve the stability of retaining walls.And the location of the node at the bottom plate can avoid the easy destruction of the post-poured node.What's more,in addition to the wet connection form of post-poured concrete,a dry connection method using sleeve grouting is proposed.For the connection between adjacent retaining walls,the forms of concave convex tenon,steel anchor bolt and post-poured concrete are put forward.For the relieving shelf,steel braces can be used instead of steel bars to ensure stable connection.Finally,the MATLAB is used to optimize the form of the retaining wall with tie bars and a relieving shelf and the form of the geogrids-reinforced retaining wall with tie bars and a relieving shelf.Taking the cost as the objective function,The effect of the overloading on the surface of the fill,the friction angle of the fill,the spacing of and the length of the geogrids is analyzed.The method of determining the parameters of optimal grid spacing and length,the reasonable position of tie bars is put forward.