钻井法深大直径立井悬浮下沉研究

Research on Suspension Subsidence of Deep and Large Diameter Vertical Shaft by Drilling Method

针对新街能源钻井法深井井壁悬浮下沉设计问题,基于阿基米德浮体悬浮原理,建立了同一断面和分段变断面的井壁结构形式在泥浆中悬浮平衡表达式,探讨了井壁混凝土重量、泥浆容重、井壁厚度对辅助钢梁支撑力和辅助钢梁施加高度的影响。并分析了泥浆容重与井壁许用临界厚度相关关系,最后验算了新街台格庙风井是否满足悬浮下沉要求。研究成果表明:(1)通过井壁混凝土减重、增加泥浆容重和减小井壁厚度,可以有效减小辅助钢梁在悬浮下沉中承受的荷载,同时显著降低辅助钢梁施加高度;(2)井壁厚度过高、泥浆容重过小将导致辅助钢梁支撑力在井壁下沉过程逐渐增大,无法实现悬浮下沉工艺;(3)泥浆容重的增大可使井壁许用临界厚度增大,同时泥浆容重一定时,井壁厚度是受限制的,实际工程中应通过增大井壁材料强度来满足施加荷载需要。研究成果可为类似钻井法凿井设计及施工提供参考。

Based on the Archimedean floating body suspension principle,the suspension balance expression of shaft wall structure with same section and subsection variable section in mud is established.The influence of shaft wall concrete weight,slurry volume weight and shaft wall thickness on supporting force and height of auxiliary steel beam is discussed.The correlation between slurry volume weight and allowable critical thickness of shaft wall is analyzed.Finally,whether Xinjie Taigemiao air shaft meets the requirements of suspension subsidence is checked.The research results show that:(1)The load of the auxiliary steel beam in suspension subsidence can be effectively reduced by reducing the weight of the wall concrete,increasing the slurry bulk weight and reducing the wall thickness,and at the same time the application height of the auxiliary steel beam can be significantly reduced;(2)Too high wall thickness and too small mud bulk weight will cause the supporting force of the auxiliary steel beam to gradually increase in the sinking process of the shaft wall,and the suspension sinking process cannot be realized;(3)The allowable critical thickness of borehole wall can be increased with the increase of slurry bulk weight.At the same time,the thickness of borehole wall is limited when the slurry bulk weight is constant.In actual engineering,the strength of borehole wall material should be increased to meet the needs of applying load.The research results can provide reference for the design and construction of similar drilling methods.