二坝蓄滞洪区分洪口门裹头工程稳定性研究

蓄滞洪区是调节河道超标准洪水的重要区域,建设蓄滞洪区对于保障区域防洪安全十分重要。为了研究长江芜湖河段二坝蓄滞洪区分洪口门裹头在扒口分洪工况条件下的稳定性,本文依据分洪口门设计资料构建了分洪口门裹头工程的三维数值分析模型,模型重点考虑了高压旋喷桩的三维加固效果以及地层的实际特征。采用强度折减法研究了裹头工程的稳定性状况,并且分析了分洪口门的变形规律。在蓄滞洪区扒口分洪工况,强度折减法计算的结果显示,相比背水侧堤身的变形,分洪口门裹头的变形量很小。堤防背水侧堤身首先出现塑性贯通区,口门稳定性最薄弱的部位在背水侧堤身,采用强度折减法计算的安全系数为2.05,大于规范要求值。说明裹头工程设计安全可靠,采用高压旋喷桩加固分洪口门十分有效,该研究成果可为类似工程设计提供参考。

Study on the stability of flood diversion gates in Erba flood detention basin

The construction of flood detention basin，which is an important area for regulating exceeding standard flood，plays a critical role in ensuring flood control safety． To study the stability of flood diversion gate of Erba flood detention basin in Wuhu under the condition of blasting flood diversion，a three dimensional ( 3D) numerical model of flood diversion gate has been established based on design data． In this model，the cement impact reinforcement effects and strata feature are mainly considered． The stability of the flood diversion gate is studied by using the finite element strength reduction method，and the deformation characteristic of the gate is also analysed． The results show that the deformation of the flood diversion gate is small compared to the back of levee in which the plastic penetrating zone first appeared． The calculated safety factor is 2. 05，which meets the requirements of the specification． It shows that the overall stability of the flood gate is good and the design is reasonable． The results can direct such engineering designs in future．