盾构开挖面极限支护力的简化计算公式

盾构开挖面极限支护力的确定是盾构法施工中一个需要解决的重要问题,基于楔形体模型对盾构开挖面极限支护力的简化计算研究,提出了极限支护力可以通过线性拟合得到。该方法将极限支护力简化为砂土内摩擦角φ的线性公式。通过对地面附加应力P₀=0,砂土的重度γ=18 kN/m³,开挖面直径D=6 m,埋深H=10 m时的lnσ_T与φ的关系曲线的线性拟合得到该条件下的盾构开挖面的极限支护力的简化计算的线性公式,又通过引入砂土的重度影响系数a、盾构的开挖面直径影响系数b和埋深的影响系数c,得出了在一定范围内适用的考虑砂土的重度、盾构的开挖面直径和埋深等影响因素的盾构开挖面的极限支护力的简化计算的线性公式,简化了盾构开挖面极限支护力的求解过程。

The Simplified Calculation Formula of Shield Tunnel Excavation Surface Limit Supporting Pressure

It is an important problem to determine the shield excavation surface limit supporting pressure in shield construction. Through the study on the calculated value from the formula of limit supporting pressure in wedge calculation model, we can find that the formula can be simplified to linear formula of internal friction angle φ of sandy soil by using the method of linear fitting. We can get the linear formula of simplified calculation of the limit supporting force of shield excavation in the condition through linear fitting of relation curve between lnσ_Tand φ when the ground additional stress P₀=0, sandy soil severe γ=18 kN/m³, excavation surface diameter D=6m, buried depth H=10m. By the introduction of influence coefficient a of sandy soil density, influence coefficient b of shield tunnel excavation face diameter and influence coefficient c of buried depth, we can get the linear formula of simplified calculation of the limit supporting force of shield excavation within a certain range applicable to consider heavy of sandy soil, shield tunnel excavation face diameter and buried depth and other factors and simplify the solving process of limit support force of shield excavation face.