三峡永久船闸人字门背拉杆预应力调试计算

Calculation for Adjustment of Diagonal Prestress of Miter Gate in Three Georges Project Permanent Lock

三峡永久船闸人字闸门通过设置背拉杆并对其施加一定大小的预应力来提高门体的抗扭性能。按三维有限元计算了单项荷载作用下人字门的应力与位移,建立了14根背拉杆预应力优化模型和简化的4根背拉杆预应力优化模型。根据优化模型得到预应力调试规律:①上层杆受拉,对上层杆应力影响大,对下层杆应力的影响量几乎可以忽略不计;反之,下层杆受拉,对下层杆应力影响大,对上层杆应力的影响量几乎可以忽略不计。②上主杆应力同时达到σ=1MPa,上副杆自动产生拉力σ=0.7MPa;下主杆应力同时达到σ=1MPa,下副杆自动产生拉力σ=0.5MPa。通过计算优化模型还确定了几组背拉杆预应力值,可供施加预应力值时参考。

By setting up diagonals applied with prestress, the miter gate in Three Georges Project permanent lock can raise the torsion rigidity. Based on three dimensional finite element method, the stresses and displacements of the miter gate applied by every single load are calculated. The 14-bar optimization model and a simplified 4-bar optimization model for calculating the diagonal prestress are established. It is deduced from the optimization models： ① When one upper diagonal is tensioned, only the stresses of the upper diagonals are changed, and those of the lower diagonals not changed almost; When one lower diagonal is tensioned , only the stresses of the lower diagonals are changed, and those of the upper diagonals not changed almost. ② As the stresses of the upper primary diagonals σ = 1 MPa simultaneously, then the stresses of the upper secondary diagonals σ =0. 7 MPa; As the stresses of the lower primary diagonals σ = 1 MPa simultaneously, then the stresses of the lower secondary diagonals σ = 0. 5 MPa. Some groups of prestress are calculated, it can be used for the adjustment of the diagonal prestress.