一种新型闸门力学性能的理论和试验研究

THEORETICAL AND EXPERIMENTAL STUDY ON MECHANICAL PROPERTY OF A NEW DOUBLE-ARCH GATE

新型双拱钢管结构闸门是大跨空间结构在水工闸门中一个新的应用,将在被誉为"中国河口第一水闸"的曹娥江大闸作为挡潮泄洪闸门首次使用。该文以曹娥江挡潮泄洪闸门为原型对这种闸门进行了力学性能的试验和理论研究,首先进行了缩尺模型试验,试验结果分析表明双拱钢管结构闸门的主要受力构件为正拱、反拱和弦杆,它们组成了共同受力系统,以承受轴向应力为主,沿跨度方向受力均匀,材料的利用率高,这说明其形体是合理和优化的。进一步分析其承载特性,发现承载特性可以分为三个阶段:弹性、局部塑性和破坏阶段,拱脚和正拱、反拱交叉节点是薄弱之处,最先破坏。接着对闸门主要受力构件进行了简化理论分析,得出了理论计算公式,并和有限元计算做了比较,验证其精度满足工程要求。

The double-arch gate is a new application for space structure to the hydraulic gate; it will be used as both tidal barrage and flood gate in the Caoe River Sluice which is so-called ＂the first estuary sluice＂ in china. Theoretical and experimental study on the gate was thusly conducted. First, a scale-model experiment of the gate was made. The data show that the main-arch, the chords and invert-arch together form mainly bearing members. The dominant stress is the axial stress and is evenly distributed along the span. In this way, the material has been put into full usage, so the designing of the gate proves to be appropriate. The load-deflection curve indicates that the load-deflection curve of the new double-arch gate consists of three stages： the elastic stage, the local plastic stage and the failure stage. The joints between the arch and springings, and the joints between the main and minor arches are the weakest parts of the gate and are destroyed first. The theoretical formula on main members is deduced as well. The results from the formula are compared with that from FEM, and it is found that the formula is accurate enough to be used in projects.