施工扰动下含水锚固围岩分区破裂演化规律研究

STUDY ON THE LAW OF ZONAL DISINTEGRATION EVOLUTION OF WATER-BEARING ANCHORED SURROUNDING ROCK ZONE UNDER CONSTRUCTION DISTURBANCE

  • 摘要: 深埋硐室围岩分区破裂是一个涉及扰动损伤、浸水劣化及锚固强化的复杂力学过程,为了探求施工扰动和地下水对锚固围岩分区破裂的影响规律,该文以深埋硐室锚固围岩为研究对象,考虑扰动损伤及孔隙水压对围岩强度参数的影响,建立杆岩协调变形的力学分析模型,基于锚固围岩分区破裂过程中锚杆中性点的分布特征,对不同扰动损伤和孔隙水压条件下锚固围岩的分区厚度、破裂区厚度、破裂区数量及其破裂时刻进行了反演分析。结果表明:深埋硐室锚固围岩分区破裂过程中沿杆体长度方向存在多个中性点,各中性点的位置与施工扰动损伤和孔隙水压的大小密切相关;施工扰动和孔隙水压会加剧锚固围岩的分区破裂化程度,具体表现为分区破裂级数和各破裂区厚度随扰动程度和孔隙水压的增大而增加;施工扰动和孔隙水在一定程度上会导致锚杆预紧力的损失,进而加剧锚固围岩的分区破裂程度。通过算例分析验证了上述认识的合理性,研究结果可为深埋硐室围岩的支护设计及优化提供参考。

     

    Abstract: In order to explore the influence of construction disturbance and groundwater on the zonal disintegration of anchored surrounding rock, it takes the anchored surrounding rock in deep buried chamber as the research object, considers the influence of disturbance damage and pore water pressure on the strength parameters in the surrounding rock, establishes a coordinated deformation mechanical analysis model for the bolt and the rock, based on the neutral point of the anchor during the zonal disintegration phenomenon in anchored surrounding rock. Inverted and analyzed are the partition thickness, zonal disintegration width, number of fracture zones and fracture moments of anchored surrounding rock under different disturbance damage and pore water pressure conditions. The results show that: There are multiple neutral points along the bolt during the fracture of anchored surrounding rock zone in deep buried chamber, and the position of each neutral point is closely related to the construction disturbance damage and pore water pressure; Construction disturbance and pore water pressure will aggravate the zonal disintegration phenomenon of anchored surrounding rock, which is manifested as the number of the zonal disintegration and, the width in each fracture zone increases with the increase of disturbance degree and pore water pressure; Construction disturbances and pore water will lead to the loss of the anchor preload, thereby aggravating the zonal disintegration phenomenon of anchored surrounding rock. Finally, the understanding is justified by case analysis, and the research results can provide a reference for the support design and optimization of the surrounding rock in deep buried chamber.

     

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