丹江口大坝加高对裂缝稳定性的影响研究

丹江口大坝初期工程存在裂缝，大坝加高会对裂缝性态产生影响。通过对丹江口大坝两个典型坝段的仿真分析，研究大坝加高过程、运行期及缝内进水情况下上游面水平裂缝、竖向裂缝、坝顶裂缝、下游面裂缝以及新老混凝土结合面的状态变化。结果显示:(1）加高过程不会引起初期大坝上游水平裂缝、大坝坝顶裂缝以及下游坝坡裂缝的扩展；(2）初期坝顶及坝坡的裂缝在加高后被新混凝土覆盖，原有裂缝在加高后运行期扩展的动因基本消失，但上游面竖向裂缝影响不明显；(3）裂缝进水后会使开度增加，有小幅度的扩展；(4）裂缝和结合面均进水后，143.0 m高程水平缝会有较大幅度扩展

Study on impact from heightening of Danjiangkou Dam on its crack stability

As cracks exist in the initial project of Danjiangkou Dam, the heightening of the dam is surely to impact the behaviors of them. Through a simulative analysis made on two typical sections of Danjiangkou Dam, the changes of the behaviors of the horizontal cracks of the upstream slope, the vertical cracks, the dam crest cracks, the cracks on the downstream face and the fresh-old concrete bonding interfaces during the periods of both the heightening construction and the operation of the dam and under condition that water intrudes into crack are studied. The results show that 1. the expansions of the horizontal cracks of the upstream slope, the dam crest cracks, the cracks on the downstream face of the initial dam body are not to be induced by the heightening; 2. as the initial dam crest cracks and the cracks on the slope are to be covered by the fresh concrete after the heightening, the motivation of the expansion of the initial crack during the operation is to be basically eliminated after the heightening, however, no obvious impact is there on the vertical crack on the upstream slope; 3. the opening of crack is to be increased with a less extent after water intruding; 4. after water intruding into both the cracks and the interfac