基于有限差分方法的双腔橡胶坝设计计算

Design of Double-Tube Rubber Dam Based on Finite Difference Method

橡胶坝是一种应用广泛的挡水建筑物.针对传统橡胶坝的挡水水位有限、对坝袋材料要求较高且坝袋易振动磨损等不足,提出了采用平行并排锚固方式的双腔橡胶坝结构.基于有限差分方法建立了双腔橡胶坝的二维结构-流体数值计算模型,利用已有理论和试验结果验证了该模型的准确性.系统分析了双腔橡胶坝的受力变形规律,得到双腔橡胶坝截面形状及张拉力变化特点.结果表明:上游水位增加,上游坝袋坝高先增加后降低,坝宽先降低后增加,下游坝袋坝高持续降低,坝宽持续增加;基于节约材料和有效提高临界挡水水位,确定了上、下游坝袋锚固间距最佳值为D=0.08L1,周长的最佳比为L_(2)=0.8L1;基于最佳锚固间距和周长比得到了不同压力水头下双腔橡胶坝变形规律及张拉力分布规律.本研究成果有望为新型双腔橡胶坝的设计计算和工程应用提供理论依据.

Rubber dam is widely used for water retaining;however,traditional rubber dams have the disadvantages of limited water retaining ability,high requirements on dam material,and easy vibration.For these disadvantages,a double-tube rubber dam with parallel and side-by-side anchorages was proposed.A two-dimensional structure-fluid numerical calculation model was established based on the finite difference method.The accuracy of the model was verified using the existing theory and experimental results.The deformation law of the proposed double-tube rubber dam was systematically analyzed,and its cross-section shape and tension variation characteristics were obtained.It is found that with an increase in upstream water level,the upstream dam’s height first increases and then decreases,whereas the width shows an opposite trend;the downstream dam’s height reduces continuously,whereas the width increases continuously.Considering saving material and effectively raising the critical water level,the optimal anchorage distance between upstream and downstream dams was D=0.08L1 and the optimal ratio of the perimeter was L_(2)=0.8L1.Based on the optimal anchorage spacing and perimeter ratio,the deformation law and tension distribution law of the proposed double-tube rubber dam at different internal water pressures were obtained.The results of this study would provide a theoretical basis for the design calculation and engineering application of novel double-tube rubber dams.