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双模盾构土压模式下下穿珠江断裂带开挖面稳定性研究

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针对盾构下穿珠江断裂带开挖面的稳定性,该文依托广州地铁7号线二期工程洪圣沙站—裕丰围站区间项目,通过盾构下穿珠江断裂带全域及其局部高风险区域的数值模拟,探明盾构穿越过程施工风险,并分析不同支护应力及注浆压力对开挖面稳定性及地层变形的影响,最后通过掘进参数分析评价数值模拟的合理性.研究结果表明:① 隧道开挖面为上软下硬地层分布时,盾构施工容易出现较大的地层沉降,当上硬下软地层分布时则易产生较大隆起;②盾构穿越复合地层时,局部软弱地层易出现开挖面稳定性问题,当软弱地层受到的静止土压力大于支护应力时,软弱地层土体将朝隧道内变形,且变形量随支护应力比的减小而增大;③ 注浆压力对开挖面稳定性无影响,但与地层沉降成反比,注浆压力越大,地层沉降越小.盾构的顺利掘进验证了数值模拟的正确性.
Stability of Excavation Face of Double-Mode Shield in Earth Pressure Mode Crossing Fault Zone of Pearl River
In view of the stability of the excavation face of the double-mode shield crossing the fault zone of the Pearl River,the project of the section from Hongshengsha Station to Yufengwei Station of the second phase of Guangzhou Metro Line Seven was studied.Through numerical simulations conducted to analyze the whole area and the local high-risk area of the shield crossing the fault zone of the Pearl River,this paper explored the construction risk of the shield crossing process.Besides,this paper analyzed the influence of different support stresses and grouting pressures on the stability of the excavation face and ground deformation,and finally,the tunneling parameters analysis was used to evaluate the rationality of numerical simulation.The results show that ① when the tunnel excavation surface is distributed with soft soil above and hard soil below,large ground settlement is prone to occur during the shield tunneling process.When it is distributed with hard soil above and soft soil below,large ground uplift is prone to occur;② The excavation face is likely to become unstable in the weak local stratum when the shield passes through the composite stratum.The soil mass in the weak stratum deforms towards the inside of the tunnel when the support stress is less than the static earth pressure in the weak stratum,and the deformation increases with the reduction of the support stress ratio;③ The grouting pressure does not affect the stability of the excavation face but is inversely proportional to the ground settlement.Greater grouting pressure indicates lighter ground settlement,and the shield tunneling verifies the correctness of the numerical simulation results.

dual-mode shieldfault zoneexcavation face stabilitynumerical simulationsupport stressgrouting pressure

佟彬、张斌、朱汉标、王树英

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中铁一局集团有限公司,陕西 西安 710054

中南大学 土木工程学院,湖南 长沙 410075

中南大学 隧地工程研究中心,湖南 长沙 410075

中南大学 轨道交通工程结构防灾减灾湖南省重点实验室,湖南 长沙 410075

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双模盾构 断裂带 开挖面稳定性 数值模拟 支护应力 注浆压力

2022年度中南大学研究生自主探索创新项目

2022ZZTS0689

2024

中外公路
长沙理工大学

中外公路

CSTPCD
影响因子:0.626
ISSN:1671-2579
年,卷(期):2024.44(5)
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