水厂新浇构筑物在基坑爆破时的抗裂性能研究

The anti-cracking performance of new laid structure for the water works under the action of blasting seismic wave

山地水厂在节能减排方面具有显著的优势,但在山地水厂的建设过程中,交叉施工可能会导致边坡、基坑等爆破作业对前期工程的新浇早龄期混凝土产生影响,产生有害裂缝。为探讨山地水厂新浇混凝土构筑物的裂缝形成与龄期之间的关系,在现场实测爆破地震波的基础上,采用数值模拟的方法研究了不同龄期大体积底板的抗裂性能。计算结果显示,对于坚硬岩石场地,当径向振速小于规范规定的安全振速时,各龄期混凝土均不会产生裂缝;当径向最大振速大于13 cm/s时,龄期7 d以下的混凝土将产生受拉破坏;而当径向最大振速降至9 cm/s以下时,龄期3 d以上的混凝土将处于安全范围。故对山地水厂大体积底板构筑物而言,其安全振速可在规范针对新浇大体积混凝土的安全标准基础上适当放宽。

The mountain water works owns the obvious advantage in terms of energy conservation and emission reduction,yet during its construction,the cross execution will produce impact of the blasting of slope and foundation on the new laid concrete structure of the former project,and harmful cracks may grow.In order to discuss the relationship of crack formation of the new laid structure between its age,based on the measured blasting seismic wave,the article use the method of numerical simulation to study the anti-cracking performance of the mass baseplate concrete of different age.The results show that,for the hard rock ground,when the maximum radial velocity is less than the safety velocity specified by the code,there will be no crack for all of the age;when the maximum radial velocity is greater than 13 cm/s,there will be tensile failure for the ages under 7 d;when the maximum radial velocity is less than 9 cm/s,the concrete will be safe for the ages above 3 d.So for the mass baseplate concrete structure of the mountain water works,it should allow appropriate relaxation on the basis of safety velocity standard provided by the code for the new laid mass concrete.