管幕预筑法中钢管顶进对地面沉降的影响

为了研究管幕预筑法中密集大直径钢管群顶进对地表沉降的影响，把平行顶管的顶管间距分为3类：大间距、中间距和小间距.明确指出了3类间距范围，总结分析了各种顶管间距情况下已建顶管对新建顶管地表沉降的影响.分析表明，大间距时已建顶管对地层的扰动影响可以忽略，中间距时主要是土体扰动的影响，小间距时既有土体扰动的影响，又有先建顶管管结构的支挡影响.分析Peck公式并对其进行修正，使之可用于预测各种间距下的地面沉降.结合沈阳地铁新乐遗址站施工监测结果，比较了地表沉降监测结果与Peck公式预测值，发现两条曲线吻合情况较好.

Influence of steel pipe jacking on earth surface settlement in pipe roof pre-construction method

In order to research the influence of jacking of dense steel pipe group with large diameter on earth surface settlement in pipe roof pre-construction method,the spacing of parallel jacking pipes was classified into such three kinds as large spacing,medium spacing and small spacing.The ranges of three kinds of spacing were clearly defined,and the effect of the existing pipes on the earth surface settlement of new pipes with various pipe spacing was summarized and analyzed.The analysis shows that the effect of the existing pipes on the soil disturbance can be ignored with large spacing,the effect is mainly soil disturbance with medium spacing,and the effect concerns both soil disturbance and support action of the existing jacking pipes with small spacing.In addition,Peck formula was analyzed and modified to predict the earth surface settlement with various spacing.In combination with the construction monitoring results of Xinle Ruins Station of Shenyang Metro,the monitoring results of earth surface settlement were compared with the values predicted by Peck formula.It is found that the two curves are in better agreement.