胶凝砂砾石坝坝坡比分析研究

Contrastive Analysis of the Cemented Sandy Gravel Dam Slope

胶凝砂砾石坝属于新型筑坝技术,坝坡比是胶凝砂砾石坝断面设计的重要参数,直接影响工程的安全性和经济性,应通过坝体抗滑稳定性和应力分析来确定最优坝坡比和坝体断面。通过和面板堆石坝、碾压混凝土重力坝坝坡比的对比,结合胶凝砂砾石坝坝体受力特征分析,对胶凝砂砾石坝在基本荷载组合条件下的坝坡比进行了理论分析和研究。胶凝砂砾石坝设计初期,类似Ⅳ类硬质岩的坝基地质条件,且材料设计抗压强度6.0 MPa、坝高小于70 m时,胶凝砂砾石坝综合坝坡比可在1.2~1.3之间初选;上游坝坡比宜大于1∶0.3、小于1∶1.0;下游坝坡比宜大于1∶0.5、小于1∶1.0。在综合坡比一定时,将坝体设计为对称梯形断面对坝体抗滑稳定有利;将坝体设计为上游坝坡比小、下游坝坡比大的非对称梯形坝对降低坝体主应力水平有利。

Dam slope is an important parameter to design the Cemented Sandy Gravel Dam. It directly affects the safety and economy of engineering. The optimal ratio of dam and dam section can be determined by the dam sliding stability and stress analysis. In this paper the dam slope is analyzed under the basic load combination through the dam slope contrast to the concrete face rock fill dam and the roller compacted concrete,combined with the stress features analysis of the Cemented Sandy Gravel Dam. The geological conditions is similar to type IV hard rock and the material＇s compressive strength is more than 6. 0 MPa,and the dam height is less than 70 m,the initial Cemented Sandy Gravel Dam slope ratio in comprehensive is 1. 2 to 1. 3. The upstream dam slope is larger than 1∶ 0.3 and less than 1∶ 1. 0,the downstream dam slope is larger than 1∶ 0. 5 and less than 1∶ 1. 0. In certain ratio the dam design for the symmetric trapezoidal cross section on the anti-slide stability is favorable. The dam design for the upstream and the downstream dam slope of non symmetrical trapezoid dam can reduce the dam stress level.