深厚覆盖层上沙坝泄洪洞沉降的有限元分析

Finite Element Analysis of Settlement of Spillway Tunnel of Sand Dam on Deep Overburden

由于缺少建筑材料,在陕北风沙区采用风积沙作为筑坝材料成为一种选择。但沙坝内修建泄洪洞等水工建筑物后,运行过程中存在沉降问题。根据已建工程,采用原型观测和数值模拟方法,分析深厚覆盖层上沙坝内修建泄洪洞的沉降规律。沙坝泄洪洞的沉降在施工过程中就已经发生,竣工期沉降值在坝轴线附近达到24.35cm;上游洞段接缝处出现了不均匀沉降,而且随荷载增加,不均匀沉降更加显著。蓄水到1064.00m时,实测和模拟计算得到的最大沉降值分别为16.00、22.80cm,相差6.80cm,在同一位置附近出现。

Due to the lack of building materials, using aeolian sand as dam filling material is an option in the sandy Region of North Shannxi. However, when the spillway tunnel and other hydraulic structures are constructed in the sand dam, the settlement issues arise in the course of daily operation. According to the project that has been built, using methods of prototype obser- vation and numerical simulation to analyze the settlement law of the spillway tunnel built in the sand dam on the deep overburden. The settlement o~ the spillway tunnel during construction has occurred, and the maximum settlement value is 24. 35cm in the vicinity of the dam axis. The seams of the upstream tunnel section generate uneven settlement, and the uneven settlement is more significant with increasing load. When the elevation of the water in the reservoir is 1064.00 m, the maximum settlement value of the prototype observation and simulation are 16.00 cm and 22.80 cm, respectively. The difference between the two methods is 6.80cm, and both of them appear near the same position.