隧道穿越富水断层破碎带掌子面失稳演化特性研究

STUDY ON INSTABILITY EVOLUTION CHARACTERISTICS OF TUNNEL FACE FOR TUNNEL CROSSING WATER-RICH FAULT FRACTURE ZONE

以某隧道穿越富水断层破碎带施工为工程背景,基于流–固耦合理论,建立了隧道穿越富水断层破碎带施工三维流–固耦合数值模型,研究隧道施工过程中掌子面失稳演化特性,分析了掌子面挤出位移、塑性区体积和掌子面涌水量的变化规律。结果表明:随着掌子面逐渐迫近断层破碎带,掌子面挤出位移、塑性区体积和涌水量呈现由“略微增加”到“明显增加”再到“急剧增大”的变化规律。防突体厚度越大,发生突水突泥灾害的概率越小,该隧道穿越F4断层施工的极限防突体厚度为5.2 m。

Taking the construction of a tunnel through a water-rich fault zone as the engineering background,based on the theory of fluid-solid coupling,a three-dimensional fluid-solid coupling calculation model for the dynamic construction of a tunnel through a water-rich fault zone is established,and the instability evolution characteristics of the palm face are investigated in the course of the tunnel construction,and the changing rules of the extruded displacement of the palm face,the volume of the plastic zone,and the amount of water inflow in the palm face are analysed.The results show that:with the palm face gradually approaching the fault fracture zone,the extrusion displacement of palm face,plastic zone volume and water influx show the change rule from"slightly increasing"to"obviously increasing"to"sharply increasing".The larger the thickness of the anti-surge body is,the smaller the probability of water and mud surges,and the ultimate thickness of the anti-surge body of the tunnel crossing the F4 fault is 5.2 m.