广州机场南航停机坪液化砂土强夯处理施工

Treatment of liquefying sandy soil under aircraft parking area for South Airline Company of Guangzhou airport by dynamic compaction

南方航空公司停机坪位于广州新白云国际机场东北角 ,占地面积 47万m2 。在停机坪范围内发现约有 3 .6万m2 大范围的粉细砂土层 ,埋置深度 3 .5m ,厚度 0 .8～ 1.4m ,上覆层为淤泥质软土。取样试验结果显示 ,当地震烈度达到 7°时 ,该粉细砂土层将产生液化 ,失去承载力 ,导致停机坪破坏。共提出 3种处理方案 ,经综合考虑经济、工期等因素 ,最终选用方案 2 ,即强夯法来处理此液化砂土层。根据拟定的强夯施工参数及技术要求 ,首先进行试夯 ,并进行参数调整 ,然后采用两台 70t履带吊机进行强夯施工 ,实际工期为 14 7d ,强夯施工结束后进行了压实度检测、标准贯入试验、静力触探及载荷试验 ,各项指标均达到设计要求 。

The aircraft park of South Airline Company is in the north-east area of New Guangzhou Baiyun International Air Port, with a area of 470 000 m\+2. Within the aircraft park, there is about 36 000 m\+2 of fine silty sand layer, 3.5 m underground and 0.8～1.4 m thick, covered by silty soft soil. The sampling test results demonstrated that the impact of earthquake intensity of Ⅶ would liquefy the fine silty sand layer and make it lose supporting capacity, resulting in damage of aircraft park. 3 treating schemes were suggested and through comparison of economy, construction period etc., the dynamic compaction method was determined to treat the liquefying silty soil layer. Based on selected parameters and technologic requirement of dynamic compaction, the trial dynamic compaction was carried out. After parameter adjustment, the dynamic compaction was carried out by 2 crawler cranes of 70 t. The practical construction period was 147 days. After the construction, the compactness check, standard penetration test, static pressure penetration test and loading test were carried out, the test results showed that various indexes met the design requirement.