斜向交叉预应力混凝土路面温度应力分析

Study on Temperature Stress of Cross Tensioned PC Pavement

针对由斜向交叉预应力混凝土路面板、砂砾分离滑动层、半刚性基层组成的路面层状体系阶跃型温度场、温度应力,预应力筋对温度应力的抵抗作用等问题进行研究。首先,建立分离式预应力路面阶跃型温度场热传导方程,并按热阻等效原理求解该温度场;然后,利用自由板理论得出预应力混凝土路面板的温度应力及预应力筋分担的温度应力,并利用MAPLE程序进行实例分析。结果表明:1 cm厚砂砾层接触热阻相当于29 cm厚混凝土路面热阻,砂砾滑动层能够有效释放路面板温度应力,斜向交叉预应力筋能够有效抵抗路面板温度应力。

For the layered pavement system which composed of cross tensioned PC Pavement slab, gravel sliding layer, and semi-rigid base, the resistance action of step-type-temperature-field （STTF）, temperature stress, and prestressing tendon on the temperature stress is researched. First, the heat transfer equations of the STTF of separated prestressed pavement is established, and the STTF is solved by the principle of thermal resistance equivalence. Then, to reach the temperature stress of the prestress concrete pavement, the temperature stress shared by prestressing tendons are obtained by utilizing the theory of edge-free plate, and instance analysis is conducted by MAPLE software. It turns out that the contact thermal resistance of l cm thick gravel layer equals to that of 29 cm thick concrete pavement, gravel sliding layer can effectively release temperature stress of pavement slab, and cross tensioned prestressing tendons can effectively resist the temperature stress of the pavement slab.