伴随着公路改扩建工程的增多，大量混凝土管涵需要加固、改造和接长． 为了研 究内衬加固混凝土管涵的力学性能，采用室内两点加载实验对高密度聚氯乙烯(HDPE) 管和型钢支架加固钢筋混凝土管涵(内径为 1． 2 m)的力学性能进行研究，获得了荷载 － 位移曲线． 通过对荷载 － 位移曲线的分析，内衬加固均不同程度的提高了混凝土管涵的承 载能力，内衬 HDPE 管提高 1． 50 倍，内衬型钢支架提高 1． 31 倍，相应的刚度则没有较大 的改变，加固后构件的延性比较好． 根据实验现象的推测，以及承载力理论计算的证实，加 固后的复合管为“套管体系”，荷载根据各个管体的刚度系数来分配，在此基础上推导的 理论公式可以用来计算加固后复合管体的极限承载力，误差小于 5%． 计算钢筋混凝土管 的刚度系数应根据受力状态采用短期或长期刚度． 当钢筋混凝土管涵损坏时，填充层在分 配荷载方面起着重要作用，而内衬管仅分担一小部分荷载． 如果复合管仅包含钢筋混凝土 管和内衬管，荷载在钢筋混凝土管和内衬管之间分担载荷，当钢筋混凝土管完全损坏时， 内衬管承载大部分荷载．

With the increase of highway extension and expansion project，a large number of concrete pipe culverts need to be reinforced，rebuilt and extended． In order to study the mechanical properties of the reinforced concrete (RC) pipes with slip-liners，the RC pipes (inner diameter of 1. 2 m) reinforced by HDPE pipe and shape steel bracket were studied by two-point loading experiments，and the load versus diameter change curve was obtained． Through analyzing the load-diameter change curve，it finds that the load-carrying capacity of the pipe is improved after reinforcement，the HDPE pipe increases 1. 50 times and the shape steel bracket pipe increases 1. 31 times， whereas the corresponding stiffness and the ductility of the rehabilitated pipes are markedly unchanged． It is proved that，according to the experimental phenomenon and the calculation results，the rehabilitated pipe is a“pipe with- in a pipe system”，so the load sharing depends on the stiffness coefficient of the pipe． The formula proposed in this study can be used to calculate the ultimate load-carrying capacity of the rehabilitated pipes，and the error is less than 5%． The short-term or long-term stiffness should be used to calculate the stiffness factor of the RC pipe． when the RC pipe is damaged，the grout plays an important role in distributing loads，and the liner shares only a small part of the load． If the rehabilitated pipe contains only the RC pipe and the liner，the load is shared between the RC pipe and the liner，and when the RC pipe is completely damaged，the liner carries most of the load．