111 / 2024-08-16 10:29:41

复合衬砌输水隧洞EVA防水卷材防水性能试验研究

输水隧洞；复合衬砌；双面自粘式EVA防水卷材；防水试验

针对复合衬砌输水隧洞结构特点及防水要求，提出一种采用双面自粘式EVA防水卷材的防水设计，通过开展防水性能试验验证防水卷材材料本体及搭接焊缝的不透水性能、研究防水卷材与初衬、二衬以及防水涂料喷涂层之间粘接面的防窜水性能。试验结果表明：EVA防水卷材材料本体以及搭接焊缝均能达到1.0MPa/24h的不透水性能；防水卷材的不同粘接面以及平整度均会对防水卷材的防窜水性能造成一定的影响：通过高分子自粘胶层与混凝土反应，二衬后浇混凝土与防水卷材粘接面的防窜水性能要优于初衬先浇混凝土与防水卷材之间的粘接面，但均能达到0.8MPa/24h的防窜水要求；对于在初衬与防水卷材之间增设防水涂料喷涂层，聚氨酯与防水卷材接触效果较差，在0.1MPa水压条件下即发生窜水，环氧树脂和丙烯酸盐这两种涂料与防水卷材之间形成的粘接面效果较好，防窜水性能均达到了1.0MPa/24h；当不平整度≥1/6时，防水卷材与混凝土之间粘接面的防窜水性能基本失效，在0.1MPa水压条件下即发生了窜水、渗漏水。

According to the structural characteristics and waterproof requirements of the composite lining water delivery tunnel, a waterproof design using double-sided self-adhesive EVA waterproof coil is proposed. The waterproof performance test is carried out to verify the impermeability of the waterproof coil material body and the lap weld, and to study the water-channeling resistance of the adhesive surface between the waterproof coil and the primary liner, the second liner and the waterproof coating spray layer. The test results show that both the body of EVA waterproof coil material and the lap weld can achieve 1.0MPa/24h impermeability. The different bonding surfaces and the levelness of the waterproof coil will have a certain impact on the anti-channeling performance of the waterproof coil: through the reaction of the polymer self-adhesive layer with the concrete, the anti-channeling performance of the second lined concrete and the waterproof coil bonding surface is better than the bonding surface between the first lined concrete and the waterproof coil, but can meet the anti-channeling requirements of 0.8MPa/24h; For the addition of waterproof coating coating between the primary lining and the waterproof coil, the contact effect of polyurethane and the waterproof coil is poor, and water breakthrough occurs under 0.1MPa water pressure. The bonding surface formed between the two coatings and the waterproof coil is better, and the anti-water breakthrough performance reaches 1.0MPa/24h. When the unevenness is ≥1/6, the anti-channeling performance of the bonding surface between the waterproof roll and the concrete is basically ineffective, and water channeling and leakage occur under the condition of 0.1MPa water pressure.