Field Test And Analysis Of Earth Pressure On Tall Counterfort Retaining Wall

The counterfort retaining wall of this article involved is a wall of reinforced concrete retaining wall. The stability of this wall-type depend on the gravity of the wall and the soil on the bottm board, soil weight on the board can effectively resist the overturning and slip, toe board also increase the stability against overturning, bending moment and shear force generated by the soil are beared by the vertical board and counterfort, that will help the strength properties of materials.Its main feature is simple structure, convenient construction, the cross section of the wall is small, light weight, low capacity area,it can adapt to the areas which lack of stone and the affordability of the groud. In general, the height of the wall should not be greater than10m. For the highly overloaded counterfort retaining wall, domestic research is very little. So, the analysis of counterfort retaining wall on this particular case has some significance.First, this article describes the various forms, role and the methods of calculating the earth pressure on the back of retaining wall at present. Then, depend on the a field test of counterfort retaining wall which located in Xiamen North station, Fuzhou-Xiamen Railway, we conducted a analysis about earth pressure of back wall and bottom board, displacement of the wall, the force of steel and geotechnical grille. Finally, we conduct a calculating about earth pressure of back wall and stability. The main conclusions are as follows:(1)《design specification of retaining structures in railway subgrade》(TB10025-2001) provide:when the height of the wall>12m, equivalent friction angle should be lower than30°. Take the observed stability data of maximum, average, minimum belong to the Imaginary wall back,we were maked a calculating and get the equivalent friction angle were33.03°、35.39°、37.44°. In other words.The range of equivalent friction angle of this retaining wall is33.03°-37.44°y calculating.It shows that the provision about equivalent friction angle which should be lower than30°is safe.(2) the earth pressure of normal direction of the counterfort depend on test is916.75kN/m, the earth pressure between counterfort is293.27kN/m. Specific value is0.76:0.23.It shows that earth pressure on the surface of counterfort is not uniform,soil behind the counterfort will produce soil arch effect on top of the counterfort because of the counterfort.huge earth pressure is beared by counterfort, earth pressure between counterfort become small.(3) geotechnical grille is a material which was forceed passively, only when the soil reaches a certain degree of lateral displacement,it can make a good function, geotechnical grille constrained the ability of soil deformation was able to play..According to the observed data show that the deformation of the wall is small,maximum displacement is6.08mm, the strain range of soil and geotechnical grille is-1500μ ε-2500μ ε.the strain is small.even it is pressing strain, it shows that adding geotechnical grille to the soil of the wall is of little effect.(4) According to the analysis of the measured data, with the decrease of equivalent friction angle overall, stability of the retaining wall in the testing spot is controled by capacity of foundation,then siding and dump, in other words, controled by capacity of foundation is control targets at first.