衬塑钢管海水海砂混凝土短柱偏压性能及承载力计算OA

Seawater sea sand concrete(SSC)-filled plastic-lined steel tubes(SSC-PLST)effectively harness the performance of each constituent material,enabling an efficient and sustainable utilization of seawater and sea-sand resources.The eccentric compressive behavior of SSC-PLST short columns was investigated through loading tests of 20 specimens,with the main test parameters being the load eccentricity and the compressive strength of SSC.Test results reveal two failure modes:overall bending failure and local buckling of the steel tube.The failure patterns of SSC-PLST columns under different eccentricities are similar to those of ordinary seawater sea-sand concrete-filled steel tubular columns,indicating that the plastic liner has no significant influence on the failure mode.As the load eccentricity increases from 0.2 to 0.8,the eccentric compressive bearing capacity of SSC-PLST short columns gradually decreases,with a maximum reduction of 68％.When the concrete strength increases from 35 MPa to 65 MPa,the eccentric bearing capacity shows a corresponding gradual increase,reaching a maximum rise of 132.6％,following a trend similar to that of ordinary SSC-FST columns.Based on the experimental findings,a refined finite element model was further developed to study the interaction and internal force distribution among the steel tube,plastic liner,and core concrete.The study shows that increasing the steel yield strength and the steel ratio significantly enhances the eccentric bearing capacity of SSC-PLST short columns,whereas the interfacial friction coefficient has a negligible effect on the mechanical performance.Finally,building upon existing design formulas for concrete-filled steel tubular members,a calculation formula for the eccentric compressive bearing capacity of SSC-PLST short columns with core concrete strength ranging from 30 MPa to 90 MPa was proposed.