摘要
2018年5月28日松原市宁江区发生M_w5.2级地震,场地效应突出,尤以液化最为显著。本文通过调查研究,指出了该次地震液化特点。分析表明:该次地震是历史上具有显著液化现象的震级最低的一次地震,发现液化场地超过200个,最大喷砂喷水砂坑直径3 m,坑深超过2 m;Ⅶ度烈度区液化场地地下水位接近7 m,超出常规认识;Ⅵ度烈度区分布10余个液化场地,喷砂冒水明显;扶余-肇东断裂、第二松花江断裂附近液化带分布明显,液化场地分布北-东方向分布明显;与地震烈度图长轴方向大体一致,液化场地条带状分布明显,以南北向分布突出。本次地震液化的特殊现象,丰富了认识,为未来规范修订和深入研究提供了线索。
The M_w5.2 earthquake occurred in Ningjiang District of Songyuan City on May 28, 2018, along prominent site effect, especially liquefaction. Through field investigation, statistics and analysis, the characteristics of the earthquake liquefaction are pointed out. In this paper the analysis indicates that this is the lowest magnitude earthquake with significant liquefaction phenomena in history. It is found that there are more than 200 liquefied sites, the maximum sand blasting pit diameter is 3 m, and the pit depth is more than 2 m. The groundwater level of liquefied sites is close to 7 m in the Ⅶ intensity region, which is beyond the conventional knowledge. More than 10 liquefied sites are distributed in the VI intensity region, and have obvious sandblasting. The liquefaction zones are obviously distributed near the Fuyu-Zhaodong fault and the second Songhuajiang fault, and the distribution of liquefaction sites is obvious in the north-east direction. The special phenomena of liquefaction in this earthquake have enriched our understanding and provided clues for future revision and in-depth study of the code.
引文
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