一、坝下涵管断裂的原因据调查(1),我省坝下钢筋混凝土埋管大多出现横向断裂。根据我省具体情况,一般认为其原因可以归结为以下几方面: 1.有的涵管设计、施工未严格按照有关规范和常规处理。如纵向不设或很少设伸缩缝;在集中荷载或基础的物理力学性能急剧变化地段未设沉降缝,如闸门井段与管身未分开,岩基与软基间未分缝等;在管身混凝土浇筑后凝结和硬化初期未妥善养护,致使收缩很大;夏季施工等等。这些方面,有关方面已作了详细调查和分析,在此不再赘述。 2.过去在坝下埋管设计中,一般均不进 First, the cause of dam under the culvert rupture According to the survey (1), our province dam reinforced concrete buried pipe transverse rupture. According to the specific conditions of our province, generally think its reason can be attributed to the following aspects: 1. Some culvert design, construction is not strictly in accordance with the relevant norms and practices. Such as vertical or rarely set expansion joints; in the concentrated load or basic physical and mechanical properties of rapid changes in the lot did not set the settlement joints, such as the gate section and the pipe body is not divided, between the rockfill and soft foundation without seams; After the concrete pouring concrete condensation and hardening the initial failure to properly care, resulting in a large contraction; summer construction and so on. In these aspects, the relevant parties have conducted detailed investigations and analyzes and will not repeat them here. 2. In the past under the dam buried pipe design, generally do not enter