复杂地质条件下竖井开挖稳定性及参数优化

Stability and Parameter Optimization of Vertical Shaft Excavation under Complex Geological Conditions

柴河水库输水工程出口竖井位于河滩地,地下水位高,且上覆第四纪土层厚度约为22.6m,为粉质粘土及粉质粘土夹碎石。因软弱土层厚,不具备常规井口固结灌浆和采用反井开挖的条件,井口开挖土体稳定性差,存在塌孔的风险。对此,以柴河水库输水工程竖井为例,采用高压旋喷墙加固井口土体,通过ANSYS有限元模拟竖井开挖过程,分析了开挖后井口土体稳定性,并对加固参数进行了优化,最终解决了柴河水库输水工程出口竖井在复杂地质条件下的开挖问题,使加固参数经济合理,对类似工程具有重要参考意义。

The outlet of vertical shaft of Chaihe reservoir water delivery project is located on the beach,where is 22.6 m quaternary layer thickness and is silty clay and silty clay with crushed stone.Because the weak soil is very thick,it is not equipped with conventional shaft mouth consolidation grouting and anti-well excavation conditions.The soil stability of shaft excavation is poor,there is a risk of collapse.For the above questions,a soft earth high pressure jet grouting wall was used to reinforce the shaft wall rock.The ANSYS finite element was adopted to simulate vertical shaft excavation process.And then,the stability of shaft wall rock was analyzed after excavation.The reinforcement parameters were optimized.The excavation problem of vertical shaft outlet of Chaihe reservoir water delivery project under complex geological conditions was solved,and reinforcement parameters were economical and reasonable,which is of great significance for similar projects.