分区破裂是深部岩体在众多敏感因素综合作用下发生的复杂时空演化过程。以深埋洞室围岩初期支护后的预应力全长锚固锚杆为研究对象，考虑不同大小托板反力作用对洞室围岩强度参数的影响，基于分区破裂条件下锚杆所呈现的拉-压交替受力特征，建立了杆体与围岩协调变形的力学分析模型，推导了围岩分区破裂后锚杆中性点位置的计算公式，进而对不同托板反力作用下的围岩分区厚度、破裂范围及数量进行了反演分析;根据围岩弹塑性界面上岩体的非线性流变模型及其在切向与径向所受的最大偏应力，提出了弹塑性界面岩体破裂发生时刻的理论公式。结果表明:① 在分区破裂条件下，深埋洞室围岩与预应力锚杆产生协调变形，沿杆体长度方向存在多个处于拉-压受力平衡的中性点，在各中性点附近的弹塑性界面上岩体具有显著的流变特性。当该界面岩体所受最大偏应力超过其长期强度时即发生脆性拉裂;② 预应力全长锚固锚杆对围岩强度参数具有重要影响，预应力的增加能够有效改善围岩的承载特性，围岩分区厚度、破裂区宽度与数量以及弹塑性界面上岩体破裂发生时刻随锚杆预应力的变化而变化;③ 在锚杆预应力作用下围岩强度的提高对洞壁岩体破裂具有一定的抑制作用。随着锚杆预应力的逐渐增大，靠近洞壁处的第1个锚杆中性点逐步向洞壁表面移动，洞壁岩体破裂区厚度也逐渐减小直至不再破裂;④ 通过算例分析对上述认识的合理性进行了验证。

Zonal disintegration is a complex spatiotemporal evolution process of deep rock mass under the com-prehen- sive action of many sensitive factors. The pre-stressed full-length anchoring bolts which were adopted for the initial support of the surrounding rock of the deep underground cavern were taken as the study object. The study considered the influence of supporting plate under different reacting forces on the strength parameters of the surrounding rock and established a mechanical analysis model about the coordinated deformation occurred between the bolt body and sur- rounding rock. A calculation formula for determining the position of neutral points along bolt body on the condition of zonal disintegration was deduced. Furthermore,the inversion analysis for the zonal thicknesses,broken ranges as well as quantities under different support plate reaction forces was carried out. According to the non-linear rheological mod- el and the maximum deviatoric stress along the tangential and radial directions of the rock mass at the elastic-plastic interface,a theoretical formula used to determine the fracture occurrence moment of the rock mass was proposed. The results show that ① under the condition of zonal disintegration,the coordinated deformation occurs between the sur- rounding rock of deep buried cavern and the pre-stressed anchor body. There are several neutral points appeared in the state of tension-compression equilibrium along the length direction of the anchor body,near which the rock mass on the elasto-plastic interface has significant rheological properties. Brittle fracture occurs while the maximum deviatoric stress from tangential to radial acted on the interfacial rock mass exceeds its long-term strength;② Pre-stressed full-length anchor bolts have an important influence on the strength parameters of the surrounding rock,and the bearing character- istics of the surrounding rock can effectively be improved with the increase of anchor pre-stress. Furthermore,the zonal thickness of surrounding rock,the width and number of fractured zone as well as the occurrence moment of sur-roun- ding rock begin to fracture change with anchor pre-stress;③ Under the action of anchor pre-stress,the strength in- crease of surrounding rock has some inhibitory effect on the fracture of the rock mass near the surface of the deep bur- ied cavern. With the gradual increase of the anchor pre-stress,the first neutral point of the anchor body is gradually moving to the surface of the cavern wall and the range of the first fracture zone gradually decreases until it reaches to zero;and finally ④ the rationality of the above conclusions is verified by a case study.