摘要
广州市轨道交通6#线东山口站左线站台隧道采用盾构先行过站后扩挖方案修建,地面环境复杂,且建筑物桩基所处地层含水量高、孔隙比大,盾构隧道扩挖施工易引起较大地面沉降。应用数值模拟方法对扩挖施工诱发地层失水引起的地表沉降以及现场扩挖施工变形控制措施的实施效果进行预测,并且运用叠加原理将得到的最终地表沉降与实测数据进行对比分析。结果显示:地层失水沉降及扩挖施工沉降比例为2∶3;盾构隧道台阶法扩挖上台阶施工地表沉降量较大,两台阶两部与两台阶四部扩挖法地表沉降差别不大,盾构扩挖法修建左线站台隧道最大地表沉降为右线CRD法站台隧道的65%;拱部大管棚、袖阀管注浆复合超前预支护增加了地表沉降槽宽度,减小了地表沉降量及倾斜;盾构轴线偏移方案减小了围岩塑形区范围,更好地发挥拱部超前预支护的效果。
Dongsharlkou station of Guangzhou metro line #6 is constructed by expanding shield driven tunnel. The ground building＇s piles are in the strata of high moisture content and void ratio, so the new station construction is easy to cause large surface settlement. Taking into account the influence of construction on the groundwater level, the application effect of in-situ deformation control measure is predicted by numerical simulation method, which is compared with the measurement data. The results show that： （1） The ratio of water loss settlement to expanding excavation settlement is 2 ＂ 3. （2） Settlement during upper-bench excavation is large, and there is little difference between two-step and four-step excavation scheme. The maximum surface settlement of shield tunnel expanding method accounts for 65% of CRD construction method. （3） the advance pre-support in the arch increases the width of the settlement trough and decreases the surface settlement and inclination. The axis deviation scheme of shield machine reduces the area of plastic zone, making the effect of the advance pre-support more obvious.
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2013年第A01期2883-2890,共8页
Chinese Journal of Rock Mechanics and Engineering
关键词
隧道工程
盾构隧道扩建
地表沉降
变形控制
沉降监测
地层失水
tunnelling engineering
shield tunnel expanding
surface settlement
deformation control
settlement measurements
water loss
