偏心卸料下大直径浅圆仓侧压力计算

CALCULATION OF LATERAL PRESSURE IN SQUAT SILO WITH LARGE DIAMETER UNDER ECCENTRIC DISCHARGE

为了研究偏心卸料下浅圆仓侧压力的计算方法,该文基于Coulomb土压力理论,结合《钢筋混凝土筒仓设计规范》(GB50077-2003)中附录C关于满仓时浅圆仓的侧压力计算方法,给出并分析了可能出现的5种工况,针对各工况下的计算公式进行详细的推导。考虑偏心卸料下筒仓仓壁的侧压力沿环向分布的不均匀性,提出了侧压力环向分布的力学模型。最后结合两个计算实例,将公式计算结果与有限元结果进行了对比,分析了偏心卸料对筒仓内力的不利影响。理论解与有限元结果吻合较好,检验了该文所推公式的正确性;偏心卸料下筒仓仓壁的水平弯矩较满载下更为不利,而环向轴力也有可能出现比满载下更不利的结果,结果验证了筒仓设计考虑偏心卸料作用的必要性。所提计算方法可供相关实际工程参考。

In order to study the calculative method of squat silo under eccentric discharge, this paper is based on Coulomb＇s earth pressure theory and is associated with Appendix C, in Code for the design of reinforced concrete silos （GB 50077-2003） which is used for calculating the lateral pressure in fully loaded squat silos. Five potential cases are analyzed. According to those five cases, relevant calculating formulae are deducted. The non-uniform distribution of lateral pressure in circumferential direction is considered and the model of mechanics is proposed. Finally, two calculative examples are presented, and the lateral pressures of which are compared with finite element method （FEM） results and used to analyze the negative effect of eccentric discharge. The theoretical results are consistent with FEM results, which verifies the validity of formulae in this paper. The results show that the horizontal moment under eccentric discharge is more disadvantage for silo than that under fully loaded, and the eccentric discharge effect for circumferential tensile is possibly more negative than that of fully loaded. The results illustrate the necessity of considering the effect of eccentric discharge in squat silos. The proposed method could be adopted in relevant practical projects.