圆形基坑排桩环梁内撑弹性支点刚度系数算法

当采用二维弹性支点法对圆形基坑排桩+环形梁内支撑支护结构进行简化设计计算时,环形梁内支撑需等效为弹簧,作为弹性支撑处理,故其刚度系数的确定至关重要。采用弹性力学的方法,对圆形基坑中的排桩环形梁内支撑结构整体进行弹性结构分析,得出环形梁内支撑与排桩支点处的水平径向位移。运用广义胡克定律,通过支点处支点力与水平径向位移的关系,确定其弹性支点刚度系数的计算公式,并参考《建筑基坑支护技术规程》,引入两个影响因素对计算公式进行修正。最后结合某提升泵站圆形深基坑实例,根据上述公式得出各道环撑的弹性支点刚度系数,利用规程规定的二维弹性支点法对该支护结构的设计思路及分析方法进行阐述,该基坑从开挖至基坑回填期间运营良好。

Calculation Method of Retaining Piles with Annular Beams Elastic Support Stiffness Coefficient Forcircular Foundation Pit

When the two dimensional elastic fulcrum method is used to simplify the design and calculation of retaining piles with annular beams strut for circular foundation pit,annular beams has to be strut equivalent to springs and elastic support,the determination of the stiffness coefficient is very important.Through elastic mechanics method,retaining piles with annular beams strut for circular foundation pit was analyzed with elastic structure,and the horizontal radial displacement of annular beams strut and retaining piles support was obtained.Using the generalized Hooke's law,through the relationship between pivot force and horizontal radial displacement,the stiffness coefficient calculating formula of the elastic support was determined.For the reference Technical specification for retaining and protection of building foundation excavations,two factors are introduced to modify the formula.Combined with an example of circular deep excavations for lifting Pump Station,according to the above formula,the elastic support stiffness coefficient of each annular beam strut was obtained.The design and analysis method of retaining and protection structure was presented by using two dimensional elastic support method.The excavation operates well during excavation and backfilling.