中文摘要：

为了研究钢筋混凝土L形柱压扭承载力的实用计算方法，利用有限元方法较系统地分析轴压比、纵筋配筋率、截面尺寸和箍筋间距对压扭作用下L形柱抗扭承载力的影响规律。建立L形截面的扭转截面系数和相当极惯性矩的简化计算方法。进行5种轴压比、3种纵筋配筋率、8种截面尺寸和3种箍筋间距共360种工况的压扭作用下L形柱抗扭承载力的数值计算，建立压扭作用下钢筋混凝土L形柱抗扭承载力的实用计算公式。研究结果表明：轴压比对L形截面的扭转截面系数和相当极惯性矩的影响很小。压扭作用下L形柱的极限扭矩随轴压比的增加、纵筋配筋率的增大和箍筋间距的减小而近似呈线性增加，但当轴压比大于0．6时其极限扭矩开始随之下降。

英文摘要：

To investigate the practical calculation method for ultimate torque of reinforced concrete columns with L-shaped cross section under combined axial force and torque, the effect of axial load ratio, longitudinal reinforcement ratio, sectional dimension and stirrup spacing on the ultimate torque was systematically analyzed using finite element method. A simplified calculation method for section modulus of torsion and equivalent polar moment of L-shaped sections was established. 360 L-shaped columns, including five axial load ratios, three longitudinal reinforcement ratios, eight sectional dimensions and three stirrup spacings, were selected for ultimate torque calculation, and a practical calculation formula for ultimate torque of L-shaped colunms under combined axial force and torque was proposed. The results show that the effect of axial load ratio on the sectional modulus of torsion and the equivalent polar moment of L-shaped section is little. The ultimate torque of L-shaped column under combined axial force and torque is increased approximately linearly with an increase in axial load ratio and longitudinal reinforcement ratio and a decrease in stirrup spacing; but it is decreased with an increase of axial load ratio when the axial load ratio is larger than 0.6.