大坝空间变形监控指标的拟定

摘要

Regarding the lack of consideration about spatiality and fuzziness in the traditional methods in drawing out the dam safety monitoring index, this paper decreases dimensions of displacement sequence at different heights in a dam by projection pursuit ( PP ) method to generate the projection displacement value and the displacement weight, and then takes the forward and inverse cloud model to draw out the safety monitoring comprehensive index for dam displacement based on the calculated weighted displacement value. Taking Mianhuatan RCC gravity dam as an example, the safety monitoring comprehensive index of horizontal displacement for No.4 dam section is worked out by PP model and the cloud model. This paper analyses the correlations between the weighted displacement of the dam body and environmental variables, and for a super scalar value of displacement, it makes comparison with the results of the confidence interval method to demonstrate the rationality and feasibility of the projection pursuit method.%针对传统方法在拟定大坝安全监测指标时对空间性和模糊性考虑的不足，采用投影寻踪方法对大坝不同高程处位移序列进行降维处理，生成位移投影值及位移权重，计算出加权位移值并运用正逆向云模型拟定大坝位移安全监控综合指标。以棉花滩碾压混凝土重力坝为例，运用投影寻踪模型和云模型拟定了4＃坝段上下游方向位移安全监控综合指标，并分析了坝体加权位移值与环境量变化规律的相关性，针对某一位移超标值，通过与置信区间法拟定结果的对比分析，论证了该方法的合理性和可行性。