如图所示，集中力作用下的简支梁模型设计，<br/> <br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/8325839_0.png"><br/> <br/> σ1=σ2时，P2＝100kN，则Pl为（　　）kN。<br/> <br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/8325839_0_1.jpg">