超长基坑开挖的空间效应

为了研究超长基坑开挖的空间效应,对盘锦某地下商业街基坑工程开挖过程进行了数值模拟,主要对基坑工程中分段、分块开挖等问题进行了计算分析。结果表明:随着基坑开挖分段长度的增加,支护桩水平位移的最大值呈先减小后增大的趋势,基底隆起量最大值呈增大的趋势;随着基坑开挖分块长度的增加,受保护侧支护桩的水平位移呈先减小后增大的趋势。超长基坑开挖时考虑空间效应可有效地减小支护结构、周围地层的变形;在基坑分段、分块开挖过程中,要考虑未开挖土体是否具有足够的强度限制支护结构及地层的变形,使得空间效应得以发挥。

Research on Construction Spatial Effects in Long Foundation Pit

Using the numerical simulation,we calculated and analyzed the process of excavation by section and block of foundation pit at Panjin underground commercial street.The results show that with the increase of the excavation section length,the maximum lateral displacement of supporting piles shows the tendency of reduction at first and increase afterwards;while the basement uplift shows the tendency of inereasing.With the increase of the excavation block length,the lateral displacement of supporting piles on protected sides shows the same tendency of reducing at first and increasing afterwards.Taking into account the spatial effect in the excavation,the long foundation pits can mitigate the deformation of supporting structure and formation effectively.Considering whether the excavated soil has enough strength to limit the deformation of supporting structure and formation in the process of foundation pit excavation with different section and block could make spatial effect significantly.