阿尔塔什水电站厂房半岩半土地基设计
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摘要
阿尔塔什水电站厂址所在位置阶地较为狭窄,而厂房尺寸较大,机组段和尾水闸墩分别置于岩、土地基上。机组段地基为砂质泥岩和泥质砂岩;尾水闸墩地基为冲积砂砾石层。岩、土地层地质特性差异大,使尾水闸墩和机组段之间易产生不均匀沉降影响厂房安全运行。面对不良的地基条件,采用何种地基处理方案是设计亟待解决的难题。本工程地基设计首先运用三维有限元计算方法对厂房地基沉降和地基应力进行计算分析,为厂房基础处理设计提供依据;其次针对特殊的地基条件,在机组段与尾水闸墩之间设结构缝,并对尾水闸墩土质地基采用桩基础的加固处理方案。不良岩、土地基设计攻克了技术难题,保证了厂房运行安全。
The terrace for the location of the site for the powerhouse of Altash Hydropower Station is narrow,but the size of thepowerhouse is larger,of which the section of power generating unit and the tailrace pier are located on rock and earth foundationsrespectively. The foundation for the section of power generating unit is sandy mudstone and shaly sandstone,while the foundationfor the tailrace pier is alluvial sandy gravel stratum. A great difference is there between the geological properties of both the rockand the earth strata,which is prone to make an uneven settlement occur between the tailrace pier and the section of power gener-ating unit,and thus impact the operation safety of the powerhouse. Facing with the poor condition for the foundation,what kindof foundation treatment scheme can be adopted is just the problem to be urgently solved during the design. In the design of thefoundation of this project,the settlement and stress of the foundation of the powerhouse are calculated and analyzed with 3-D fi-nite element method at first,so as to provide a basis for the design of the foundation treatment;and then the structural joint is ar-ranged between the tailrace pier and the section of power generating unit and a pile-foundation strengthening scheme is adoptedfor the earth foundation of the tailrace pier for the special condition of the foundation. Finally,the technical problem is overcomethrough the design of the poor rock-earth foundation,thus the operation safety of the powerhouse is ensured as well.
The terrace for the location of the site for the powerhouse of Altash Hydropower Station is narrow,but the size of thepowerhouse is larger,of which the section of power generating unit and the tailrace pier are located on rock and earth foundationsrespectively. The foundation for the section of power generating unit is sandy mudstone and shaly sandstone,while the foundationfor the tailrace pier is alluvial sandy gravel stratum. A great difference is there between the geological properties of both the rockand the earth strata,which is prone to make an uneven settlement occur between the tailrace pier and the section of power gener-ating unit,and thus impact the operation safety of the powerhouse. Facing with the poor condition for the foundation,what kindof foundation treatment scheme can be adopted is just the problem to be urgently solved during the design. In the design of thefoundation of this project,the settlement and stress of the foundation of the powerhouse are calculated and analyzed with 3-D fi-nite element method at first,so as to provide a basis for the design of the foundation treatment;and then the structural joint is ar-ranged between the tailrace pier and the section of power generating unit and a pile-foundation strengthening scheme is adoptedfor the earth foundation of the tailrace pier for the special condition of the foundation. Finally,the technical problem is overcomethrough the design of the poor rock-earth foundation,thus the operation safety of the powerhouse is ensured as well.
引文