Analysis And Research On The Bearing Capacity Of Ground-Supported Steel Silos

With the rapid development of Chinese economy, many producing fields have reveled a large need of steel silos. But steel silo structure theory and design methods in our country can't meet the requirement. According to the great needs of no-pillars steel silos, this thesis mainly investigates no-pillars steel silos.The accurate loads are the precondition of the design of safe and economical silos. Firstly, this thesis simulates the silo wall pressure by the use of FEM program ANSYS. In the thesis, the storages in silos adopt Drucker-Prager yielding rule to reflect the real mechanics capability. And the thesis uses transient analysis to model the storage discharging. The analysis result in this thesis nicely accords with the experimental result in the literature. According to the analysis, the thesis presents some suggestions on the storage load.The steel silo is a kind of thin-wall shell structure, so it is sensitive to imperfection. Secondly the thesis comprehensively analyzes the elastic stability of the ground-supported steel silos, and tries to import random imperfection method to truly relect the practical mechanism capability. The random imperfection can really reflect the truely structure's capability. The thesis considers 3 kinds of imperfection forms: the welded-joint imperfection, the consistent mode imperfection and the random imperfection. The thesis particularly analyzes every imperfection form's influence on the silo's capability. Comparing 3 kinds of imperfection forms, this thesis draws the conclusion that the consistent mode imperfection is the most adverse one.At last, the thesis describes"elephant's foot"failure at large, and analyzes the bottom of silos with large-displacement and elastic-plastic methods , and reveal the failure mechanism and the failure process. Then the thesis analyzes bending effect's influence on displacement and stress state at the bottom of silos. According to multiple model results, the thesis fits the maximum Von Mises stress formula. The formula is based on the geometric nonlinear analysis result. The maximum Von Mises stress formula is more simple and precise, and can be used to the silo's foot design.