In deep underground mining, achieving stable support for roadways along with long service life is critical and the complex geological environment at such depths frequently presents a major challenge. Owing to the coupling action of multiple factors such as deep high stress, adjacent faults, cross-layer design, weak lithology, broken surrounding rock, variable cross-sections, wide sections up to 9.9 m, and clusters of nearby chambers, there was severe deformation and breakdown in the No. 10 intersection of the roadway of large-scale variable cross-section at the − 760 m level in a coal mine. As there are insufficient examples in engineering methods pertaining to the geological environment described above, the numerical calculation model was oversimplified and support theory underdeveloped; therefore, it is imperative to develop an effective support system for the stability and sustenance of deep roadways. In this study, a quantitative analysis of the geological environment of the roadway through field observations, borehole-scoping, and ground stress testing is carried out to establish the FLAC 3D variable cross-section crossing roadway model. This model is combined with the strain softening constitutive (surrounding rock) and Mohr–Coulomb constitutive (other deep rock formations) models to construct a compression arch mechanical model for deep soft rock, based on the quadratic parabolic Mohr criterion. An integrated control technology of bolting and grouting that is mainly composed of a high-strength hollow grouting cable bolt equipped with modified cement grouting materials and a high-elongation cable bolt is developed by analyzing the strengthening properties of the surrounding rock before and after bolting, based on the Heok-Brown criterion. As a result of on-site practice, the following conclusions are drawn: (1) The plastic zone of the roof of the cross roadway is approximately 6 m deep in this environment, the tectonic stress is nearly 30 MPa, and the surrounding rock is severely fractured. (2) The deformation of the roadway progressively increases from small to large cross-sections, almost doubling at the largest cross-section. The plastic zone is concentrated at the top plate and shoulder and decreases progressively from the two sides to the bottom corner. The range of stress concentration at the sides of the intersection roadway close to the passageway is wider and higher. (3) The 7 m-thick reinforced compression arch constructed under the strengthening support scheme has a bearing capacity enhanced by 1.8 to 2.3 times and increase in thickness of the bearing structure by 1.76 times as compared to the original scheme. (4) The increase in the mechanical parameters c and φ of the surrounding rock after anchoring causes a significant increase in σ_t; the pulling force of the cable bolt beneath the new grouting material is more than twice that of ordinary cement grout, and according to the test, the supporting stress field shows that the 7.24 m surrounding rock is compacted and strengthened in addition to providing a strong foundation for the bolt (cable). On-site monitoring shows that the 60-days convergence is less than 30 mm, indicating that the stability control of the roadway is successful.

在深部地下开采中，实现巷道的稳定支护和长使用寿命至关重要，而该深度复杂的地质环境往往是一项重大挑战。由于深部高应力、相邻断层、跨层设计、岩性薄弱、围岩破碎、断面变化、断面宽达9.9 m、近室成簇等多重因素的耦合作用，严重某煤矿-760m水平大变断面巷道10号交叉口变形破坏. 由于上述地质环境工程方法实例不足，数值计算模型过于简单，支撑理论欠发达；所以，必须为深部道路的稳定性和维持建立有效的支持系统。本研究通过现场观测、钻孔范围和地应力测试对巷道地质环境进行定量分析，建立FLAC 3D可变断面穿越巷道模型。该模型结合应变软化本构（围岩）和Mohr-Coulomb本构（其他深部岩层）模型，基于二次抛物线莫尔准则构建深部软岩压缩拱力学模型。通过分析锚固前后围岩的加固性能，开发了以高强度空心注浆锚杆配用改性水泥灌浆材料和高伸长锚杆为主体的锚杆注浆一体化控制技术。基于 Heok-Brown 准则。通过现场实践，得出以下结论：（1）该环境下横巷顶板塑性区深约6 m，构造应力近30 MPa，围岩为严重断裂。(2) 巷道变形由小断面向大断面逐渐增大，在最大断面处几乎翻倍。塑性区集中在顶板和肩部，从两侧到底角逐渐减小。靠近通道的交叉路口两侧的应力集中范围越来越大。(3) 加固支护方案下建造的7m厚加筋受压拱，比原方案承载力提高1.8～2.3倍，承载结构厚度增加1.76倍。(4)机械参数的增加 与原方案相比，承载结构厚度增加3倍，增加1.76倍。(4)机械参数的增加 与原方案相比，承载结构厚度增加3倍，增加1.76倍。(4)机械参数的增加锚固后围岩的c和φ导致σ _t显着增加；新型注浆材料下方的索锚拉力是普通水泥浆的2倍以上，经测试，支护应力场表明，7.24 m围岩除提供了坚固的基础外，还得到了压实和加固。用于螺栓（电缆）。现场监测显示，60天收敛小于30毫米，表明巷道稳定控制成功。