地铁车站附属工程高程爬升段受施工工期、地面空间不足、既有接驳等条件制约需采用仰挖法施工。通过数据统计分析仰挖施工沉降规律及影响因素，通过实际案例进行仰挖与俯挖实测分析和数值分析对比研究探索沉降规律。研究表明：1）拱部为砂性土时87.3%的测点沉降量在3 mm~60 mm之间，拱部为粘性土时59.2%的测点沉降量在3~30mm，拱部为卵石层时测点分布离散。2）沉降槽宽度粘性土≈砂性土＞卵石，粘性土与砂性土沉降槽宽度约为出入口或通道宽度的3倍，卵石沉降槽宽度约为出入口或通道宽度的1倍。3）仰挖施工最大沉降比俯挖施工大约75%，仰挖施工最大沉降发生于爬坡段约1/2处，而俯挖施工最大沉降更接近于埋深最小处。研究结论可用于初步判断仰挖施工沉降量范围、沉降控制最不利部位。

The down-top excavation method is used for elevation climbing section of the metro station ancillary project ,due to the restricted by the construction duration, the lack of ground space, the existing connection and other conditions.Through the statistic analysis of the down-top excavation construction settlement rule and influencing factors, and the settlement law was explored by comparing the measured analysis and numerical analysis of the down-top and dig-down two excavation cases. The results show that: 1) The arch is sandy soil ,87.3% of the measurement point settlement amount is between 3~ 60mm.The arch is clay soil ,59.2% of the measurement point settlement is between 3~ 30mm. The arch is pebble layer ,the measurement point distribution is dispersed.2) The arch is the relationship between the amount of sedimentation and the buried depth when the clay soil is clay and sandy soil, and the relation is basically proportional linear when the arch is pebble. 4) The maximum settlement of the down-top excavation construction is about 75% of the dig-down construction, it occurs in about 1/2 of the climbing section, and the maximum settlement of the dig-down construction is closer to the lowest depth. The conclusion of the study can be used to make a preliminary judgment on the range of subsidence and the most unfavourable part of settlement control.

U455

企业双创基金（SCJJ2021005）