Research On The Working Mechanism Of Divided Box And Its Application In Soft Foundation Reinforcement

The divided box is an improved type of soilbag,which greatly improves its performance by adding high-strength truss slings in the bag.When dealing with the soft foundation,the divided box uses the forced pressure to eliminate most of the foundation settlement,and quickly drains the water on the soft soil to form a hard shell layer,so as to realize the efficient reinforcement treatment of the soft foundation.This paper takes the temporary road foundation reinforcement project of a subway station in Tianjin as the background,carries out the indoor test and the test section construction on the divided box,which can provide certain reference for the promotion and application of this new foundation reinforcement technology in our country in the future.In this paper,several groups of uniaxial compressive strength tests are carried out on the divided box monomer,and the relationship between deformation and bearing capacity of divided box with different fillers,different sealing methods and different types was obtained.When gravel and steel slag are used as fillers,the compressive strength of PD-100 divided box is greater than 2.5MPa,and that of PD-150 divided box is greater than 1.1MPa.Based on the theoretical formula of compressive strength of divided box without considering internal constraints,the strength of PD-100 divided box and PD-150 divided box with steel slag and crushed stone as fillers are calculated respectively.By comparing the calculated value with the test value,it is found that the test value is always greater than the calculated value.It is further verified that the stiffened sling inside the divided box has a certain effect on improving the vertical bearing capacity of the divided box.In order to meet the traffic of heavy earthmoving trucks and concrete tank trucks during the construction of the subway station,the test section construction was carried out.The temporary road 30 m long and 6m wide was laid by using the divided box,and compared with the traditional method of replacing the temporary road laid by 50 cm gravel layer.Through the plate load test,the average bearing capacity eigenvalue of the foundation strengthened by the divided box is 159 k Pa,which meets the design requirements and is much higher than that strengthened by the gravel cushion.By monitoring the pore water pressure of the foundation strengthened by the divided box,it is found that the pore water pressure dissipates quickly within 1m depth from the bottom surface of the divided box.Figure [52] Table [19] Reference [51]...