盾构注浆荷载作用下带榫管片水平轴线偏移量计算方法研究

STUDY ON CALCULATION METHOD OF HORIZONTAL AXIS OFFSET OF MORTISE SEGMENT UNDER SHIELD GROUTING LOADING

为探明隧道盾构注浆荷载作用引起带榫管片水平轴线偏移规律,以小曲率半径盾构隧道为例,分析壁后注浆引起管片上浮的诱因,考虑管片环“椭圆化”变形、纵向连接螺栓预应力、环缝影响范围和横向刚度等综合因素的影响,建立榫杆连接条件下带榫环缝的管片单元纵向等效抗弯刚度有效率计算式,并通过计算盾构注浆荷载作用下带榫管片的静态和动态上浮力,构建盾构注浆荷载作用下带榫管片上浮力计算表达式,由此分析小曲率半径隧道盾构注浆荷载作用下带榫管片受力情况及其在文克尔弹性地基梁假定条件下受上浮力作用的挠曲变形规律,建立盾构注浆荷载作用下带榫管片水平轴线偏移量计算方法,并依托实际工程加以验证。结果表明:该文理论值与模拟值和监测值均拟合良好,该文计算方法具有良好的工程适用性,可为盾构隧道工程及其类似工程中注浆荷载作用下管片偏移及错台问题提供有效的理论指导。

In order to find out the horizontal axis offset law of mortise segments caused by grouting loading of tunnel shield,the causative factors of mortise segments uplift caused by back-filled grouting are analyzed by taking a small curvature radius shield tunnel as an example.Considering the deformation of"ellipticization"of segment rings,pre-stressing of longitudinal connecting bolts,the influence range of ring joints and transverse stiffness,established was the calculation formula for longitudinal equivalent bending stiffness of segment unit with mortise ring joints under mortise connection conditions.By calculating the static and dynamic uplift force of the mortise segments under the shield grouting loading,constructed was the expression for the uplift force of the mortise segments under the shield grouting loading.Based on this,analyzed were the force on the mortise segments under shield grouting loading in small curvature radius tunnels and its deflection and deformation law under the assumption of Winkel's elastic foundation beam,and established was the calculation approach for the horizontal axial offset of the mortise segments under the shield grouting loading.And it was verified upon the practical engineering.The results show that the theoretical values in this study fit well with the simulated values and monitoring values.The calculation approach of this study can be suitable for practical engineering well.It can provide an effective theoretical guidance for segments offset and misalignment under grouting loading in shield tunneling project and similar projects.