Structural Analysis and Design Method for Subgrade Bed of High-speed Railway

Based on field test data,the dynamic load,stress and deformation characteristics of subgrade are analyzed.Train load is distributed to sleepers in proportion.The dynamic load,stress and deformation of subgrade are calculated by adopting the method of Boussinesq elasticity theory formula and with Odemark equivalent hypothesis of modulus-thickness.When the value of modulus in calculation is decided by standard of strain,the result of calculating is consistent with the test.Thus a method of calculating for subgrade is proposed.With volumetric cyclic threshold shear strain,a design method of subgrade on control strain is advanced.The idea is to control accumulative effect such as accumulative deformation and pore water pressure of subgrade.