五、应用实例经结构设计计算的各类混凝土管作为产品进行生产后,由于混凝土材料本身特性及在生产工艺流程中某些环节的不完善或操作人员疏忽,有的产品虽经一般检测手段检验确证产品合格,但并未暴露管体结构的内在矛盾,留下隐患,给工程带来损失。如某工程的三阶段输水管线,每根管子出厂前均经内水压检查,但铺设后不到一年时间在第二次通水时,连续多处发生管体爆裂,致使管线不能按期使用,管线投资损失200余万元。经应变测试检查,发现管体环向钢筋多数出现超张拉,加之回填土压力的作用,致使 V. Application examples After concrete pipes calculated by structural design are used as products for production, due to the inherent characteristics of concrete materials and certain links in the production process, such as imperfections or operator negligence, some products are tested by ordinary inspection methods. Confirmed that the product is qualified, but did not reveal the inherent contradiction of the pipe structure, leaving hidden dangers and causing losses to the project. For example, for a three-stage water pipeline of a project, each pipe is checked by the internal water pressure before it leaves the factory, but when it is laid for the second time in less than a year after it is laid, bursts of pipe occur in multiple places in succession, resulting in the failure of the pipeline. On schedule, the pipeline investment lost more than 2 million yuan. After the strain test examination, it was found that most of the hoop reinforcement of the pipe body was super-tensioned, and the effect of backfill pressure was added.