Rock Support Research Articles

Study on Surrounding Rock Control of Withdrawal Space in Fully Mechanized Caving Mining of a 19 m Extra-Thick Coal Seam

The section span of the withdrawal space of fully mechanized top coal caving in an extra-thick coal seam is large, and with the gradual withdrawal of the hydraulic support, a series of strong dynamic pressure disasters occur in the withdrawal space, and the difficulty of surrounding rock support control increases sharply. In order to study the control mechanism of surrounding rock in the final mining withdrawal space in detail and put forward a reasonable support technology scheme, taking the large-section withdrawal space of an 8309 fully mechanized caving face in an extra-thick coal seam of a mine as the research object—through the theoretical investigation of whether the key blocks of the main roof are stably hinged under varied stopping coal caving distances and fracture locations of the main roof—the reasonable and optimal stopping coal caving distances and roadway formation time are determined. Using numerical simulation and similar simulation methods, the vertical stress and the maximum shear stress research indicators were introduced to verify the accuracy of the theoretical analysis results. The results show the following: (1) The reasonable stopping coal caving span is 1~2 times the cycle weighting interval, the best stopping coal caving distance in this geological condition is 30 m, and the best fracture position of the main roof is located above the goaf. (2) The migration of overlying strata in the withdrawal space has obvious zoning characteristics, and the zoning is as follows: a stopping coal caving area, support area of the hydraulic support, withdrawal channel area, and stopping coal pillar area. (3) According to the zoning characteristics of overlying strata movement, the asymmetric zoning support control scheme of the withdrawal space is proposed. The field monitoring results show that the maximum roof subsidence in the withdrawal space is 151 mm, the maximum internal squeezing amount of the stopping coal pillar is 82 mm, and the supporting and anchoring effect of each partition in the withdrawal space is good. The set of partition asymmetric support control schemes has been successfully applied to field practice.

Exploring the axial performance of protective sheathed rock bolts through large-scale testing

Understanding the axial load transfer mechanism of rock bolts under diverse conditions is essential for optimizing reinforcement in rock structures, advancing our comprehension of rock support, and facilitating the design of robust engineering solutions. This paper reports the outcomes of an extensive experimental investigation, focusing on the axial behavior of protective sheathed rock bolts employed in corrosive environments, assessed through pullout tests. Three distinct testing setups were designed to evaluate comprehensively the performance of these rock bolts in various scenarios. The results indicated that the failure characteristics and axial behaviors of sheathed rock bolts differ significantly from conventional counterparts. The findings revealed two primary failure modes in sheathed rock bolts: bolt rupture and slip at the grout-sheath interface, based on the testing arrangement and encapsulation length. The lack of adhesion and interlocking at the grout-sheath interface prevents shear stress at the bolt-grout interface from reaching its maximum potential strength, resulting in grout damage manifesting as circumferential cracks. This, in turn, initiates crack formation, reducing the system’s bond strength. Additionally, it causes slip at the grout-sheath interface to occur at lower pullout loads. It can be inferred that the inner surface of the plastic sheath lacks the necessary structural integrity to withstand high loads, significantly impacting bond stress distribution and failure modes. The results demonstrate that the protective sheath remains intact up to an axial displacement of 28 mm, irrespective of the testing configuration. Additionally, it was observed that the maximum bond stress at the bolt-grout interface falls within the range of 6–8.7 MPa, which is below the shear strength of the grout. Consequently, achieving failure at the bolt-grout interface is not feasible.

Fatigue mechanical properties and Kaiser effect characteristics of the saturated weakly cemented sandstone under different loading rate conditions

Weakly cemented sandstone (WCS) is a unique rock type widely distributed on the surface. Environmental factors such as groundwater and stress variations easily influence its fatigue mechanical properties and fracture characteristics. To design and evaluate the long-term stability of surrounding rock support in tunnel excavation and underground resource mining projects, investigating the fatigue mechanical properties and acoustic emission (AE) response characteristics of saturated WCS under different loading rates is of great practical and theoretical significance. This study employed experimental techniques such as X-ray diffraction (XRD), nuclear magnetic resonance (NMR), and natural water absorption tests to investigate the mineral composition, pore size, and connectivity characteristics of WCS. The multi-level cyclic loading-unloading tests (MCLU) combined with the AE system were conducted on dry and saturated WCS specimens at different loading rates. The results reveal that the deformation modulus of these specimens initially increases and then decreases under cyclic loading conditions. Water significantly influences the fatigue strength and deformation resistance of sandstone. As the loading rate increases, the range of RA values broadens, accompanied by a marked increase in the number of AE signals with high RA values. Saturated sandstone specimens are more prone to developing macroscopic shear fracture surfaces. Water has a more substantial effect on the stress distribution ranges corresponding to the response of the Kaiser effect in WCS than loading rates. The capacity of the Kaiser effect to indicate the extent of rock damage is intricately linked to the progression of internal micro-cracks. When internal damage surpasses the critical value of the Kaiser effect memory damage, the accelerated propagation of shear cracks becomes pivotal in the internal damage of the sandstone. It seems that the presence of water within the interior of the rock may facilitate the dissolution of K-feldspar in WCS, which could result in the formation of kaolinite, which will be further transformed into illite. The hydration expansion of illite may further exacerbate the deterioration effect of the mechanical properties of WCS.

Probabilistic Approach for Q-based Ground Support Design

For tunnel, cavern, and shaft design, the inherent variability in a given rock mass domain makes accurately estimating rock mass quality and support requirements difficult. To capture the variability in rock mass properties when using the Q system, a methodology incorporating a statistical analysis of measured Q input parameters and Monte Carlo Simulation was developed to perform a probabilistic ground support design approach. Probability and cumulative density function curves were then developed using the mathematical program MATLAB to guide in estimating ground support based on all potential rock mass conditions. To illustrate the proposed approach, two hypothetical tunnels were designed based on real data from two previous projects. Finite Element Modelling was used to evaluate the suggested Q rock support performance in a range of rock conditions for one of the hypothetical excavations to validate the proposed approach. This method demonstrated that associating a range of potential ground conditions instead of a single deterministic value for each input parameter can provide a quantifiable measurement of uncertainty within a given rock mass domain. Additionally, the approach provides insight into the design criteria for ground support in underground excavations to potentially reduce overly conservative and costly recommendations.

Study on Influencing Factors and Prediction of Tunnel Floor Heave in Gently Inclined Thin-Layered Rock Mass

In recent years, the construction of new railway tunnels worldwide has become increasingly challenging due to larger cross-sections, deeper burial depths, higher in situ stress, and more complex geological conditions. During both construction and operation, some tunnels have encountered significant issues with floor heave. This paper begins by identifying the primary causes of deformation and instability in tunnel floor structures through an investigation and statistical analysis. It then examines floor heave across more than 20 railway lines, summarizing the types, generation mechanisms, and mechanical models associated with this issue. Additionally, extensive survey data indicate that tunnel floor heave is most likely to occur in gently inclined thin-layered rock masses. Therefore, using a tunnel passing through the plate suture zone in such a rock mass as a case study, numerical simulations, theoretical analyses, and on-site monitoring were conducted. This study systematically analyzed the influence of single and multiple factors, as well as the mechanical behavior of the support system, on tunnel floor heave in gently inclined thin-layered surrounding rock. Furthermore, several key models were proposed: a tunnel floor heave estimation and load formula based on a mechanical model, a dynamic relationship between surrounding rock support force and tunnel floor heave using the Nishihara model, a tunnel floor settlement estimation formula based on deformation statistics, and a tunnel floor heave energy prediction model utilizing the B-P neural network algorithm. These conclusions have been validated and widely applied in practical engineering, providing a robust theoretical foundation and technical support for future tunnel construction.

Design of Rock Support in Low Overburden and Hard Rock Conditions with the use of Rock Mass Classification Systems and Numerical Analyses: a Study Based on the Construction of the Hestnes Railway Tunnel, Norway

AbstractEngineering rock mass classifications are used to describe rock masses and to assist in the design of rock support in hard rock tunneling. In most of the encountered geological- and rock mechanical conditions, from hard and competent rock to poor and fractured rock masses, the application of classification systems has normally resulted in successful and economic designs. However, complex ground conditions as these derived from tunneling in low rock overburden pose several challenges to rock mass classification and support design. In the present study, an analysis of the ground behavior and tunnel stability in a portion with very low rock overburden during the construction of the Hestnes railway tunnel (Norway) was conducted to investigate the performance of the current classification practice for tunnel rock support design. The results have revealed several challenges, which are related to conservative rock mass and rock support assessments due to the lack of consideration of the important stabilizing effect that rock arching has on tunnel stability. It was also found that with the application of an integrated methodology able to combine classification methods with numerical simulations and detailed information of the ground properties and behavior, more optimal designs in the form of rock reinforcement with bolts and shotcrete can be achieved when rock mass quality Q < 1. On this basis, a set of design recommendations was developed for the integration of classification systems with more elaborated engineering design analyses to provide guidance in design optimization for hard rock tunnels subject to low overburden.

Design of Rock Support in Hard and Layered Rock Masses Using a Hybrid Method: A Study Based on the Construction of the New Skarvberg Tunnel, Norway

AbstractHard rock formations with layered, anisotropic geological structures are rather common in Norway. The design of tunnel rock support under such ground conditions has been traditionally done with an empirical approach and assisted with engineering rock mass classification. In most cases, rock stability has been achieved with the use of fiber-reinforced sprayed concrete combined with rock bolts, sometimes supplemented with ribs of reinforced sprayed concrete (RRS) and bolt spiling. However, the discontinuous character and more complex ground behavior of layered rock can lead to design challenges as experienced during the construction of the new Skarvberg highway tunnel in Northern Norway. A significant portion of the tunnel exhibited consistent overbreak, delamination problems and a tunnel failure. In this article, the ground behavior and rock support performance at different locations of the tunnel are investigated to find a basis for design optimization of rock support under similar ground conditions. For this purpose, a thorough site investigation program was carried out, which formed the basis for further assessments and analyses with a hybrid design methodology and the numerical code UDEC (Itasca). As a result, the main challenges of classification systems to capture ground behavior and derive optimal support design in layered rocks were identified. As such, this study has investigated design optimization possibilities, which resulted in the development of, among others, a specific ground behavior classification for layered grounds and a new, optimized RRS-support concept for layered rock masses of very poor quality (e.g., Q ~ 0.1–1).

Research on Rock Support Technology of Railway Tunnels Based on Geomechanical Model Tests

Research on Rock Support Technology of Railway Tunnels Based on Geomechanical Model Tests

Mechanical Tests and Theoretical Research on Fracture Grouting Reinforcement of Soft and Weak Coal Rock

Mechanical Tests and Theoretical Research on Fracture Grouting Reinforcement of Soft and Weak Coal Rock

Разработка технологии проведения и крепления горной выработки в зоне тектонически-ослабленных пород

Presence of tectonically weakened and disturbed zones leads to decreased underground excavation rates and reduced safety of the mining operations. As a rule, such zones are bounded by vertical and subvertical disturbances that contribute to weakening and loss of stability of the rock and ore mass. Disturbance of the natural state, in particular driving of a mine workings, provokes irreversible deformations due to redistribution and concentration of stresses within the boundary rock mass, which is more rigid. At the same time no significant stresses are formed within the rock mass of the tectonic zone due to its caving. Therefore, when developing solutions for driving and supporting mining excavations within the tectonic zone, the rock mass should be considered as weakened and highly fragmented with unbonded structural blocks. The particle-size distribution within the rock mass of the tectonic zone varies in a wide range of sized from several to tens of centimetres. In this context, the mining and rock reinforcement technology presented in this paper accounts for the possible free caving of the non-bonded host rock mass made up of small-sized blocks. The paper discusses physical and mechanical characteristics and the stress-and-strain state of the rock mass within the tectonically weakened zone and the boundary host rocks, and a technology of driving and supporting underground mine workings is proposed on this basis.

Stability Evaluation of Lanedada Twin Tunnel in KTFT

The construction of underground tunnels, particularly in roadway systems, is a highly complicated and demanding process, necessitating careful consideration of geological variability, environmental impact, and safety concerns. This thesis emphasizes the critical importance of determining the optimal separation between twin tunnels, balancing the need for environmental conservation, economic efficiency, and structural stability. The study particularly focuses on the Kathmandu Terai/Madhesh Fasttrack (KTFT), a major expressway project in Nepal, which includes twin tunnels at three different sites under varying geological conditions. A detailed case study is conducted on the Lanedada Twin Tunnel, spanning 1.430 kilometers through the Siwalik Hill. Various methodologies, including empirical, analytical, and numerical approaches, are employed to assess tunnel stability. The findings reveal discrepancies in predictions of tunnel squeezing, with Singh et al.'s method indicating no squeezing potential, while Goel et al.'s method identifies squeezing in half of the evaluated sections. Additionally, the approaches by Hoek and Marino (2000) and Shrestha and Panthi (2015) are applied to estimate tunnel deformation at six specific locations. An analysis of rock support systems using the Rock Massm Rating (RMR) classification and the Q system is presented. Special attention is given to the section at 34+160, where the RS2 software is utilized to simulate varying pillar widths between the twin tunnels, allowing for a comparative analysis of different scenarios. This research aims to contribute to the understanding and implementation of safer, more feasible twin tunnel constructions, thereby enhancing the effectiveness of large-scale infrastructure projects.

A novel cement-based interface functional material for application onto shotcrete-rock interface of tunnel in cold regions

In cold regions, the “natural weak zone”+“frost heave cracking” problems at the interface between shotcrete and rock will superimpose damage to the shotcrete-surrounding rock support system structure. However, there is no direct and effective technique to improve the bond strength and frost resistance of shotcrete for infrastructure such as tunnels in cold regions. Based on this, this study innovatively proposes the pretreatment technology of the interface between shotcrete and surrounding rock in tunnels in cold regions, and tries to investigate the fracture evolution of the binary and the distribution characteristics of the interface transition zone (ITZ) in cold regions under the action of interface functional material (IFM) by relying on the techniques of mechanical strength test, morphology analysis, and microstructure test. The study showed that: (1) the optimal mix ratio of IFM was designed as cement (10)+water (4)+calcium acrylate(1.5 %)+bamboo liquefied binder (4 %)+acrylate laminating adhesive (8 %)+ICA (2 %). At room temperature, the shear strength of the binary sample pretreated with the IFM was elevated by 1.56 MPa compared with that of the normal sample, and this increase could be raised to 1.64 MPa under freeze-thaw cycles (FTC). (2) As the freeze-thaw effect intensifies, the number of sandstone particles adhering to the failure surface of the binary increases correspondingly, and the morphology of the failure surface also becomes more undulating. This is due to the fact that after a certain FTC, more cracks are deflected towards the sandstone side due to the higher degradation of the sandstone compared to the ITZ. (3) Under FTC, the application of IFM will lead to an increase in the proportion of sandstone adhering to the failure surface and the fractal dimension of the failure surface, and this phenomenon becomes more pronounced with the intensification of FTC. (4) In the ITZ space, the hydration products and pore structure of the area closer to the sandstone are worse, the use of IFM can optimize this phenomenon. The new idea of utilizing the surrounding rock surface pretreatment technology to improve the bond strength and frost resistance of shotcrete proposed in this study has good application prospects in the construction of tunnels and other infrastructures in cold regions.

Stability control of goaf‐driven roadway surrounding rock under interchange remaining coal pillar in close distance coal seams

AbstractThe roadway surrounding rock stability under the influence of interchange remaining coal pillar in close distance coal seams is one of the key factors affecting the coal mines safe and efficient mining. To reduce the roadway deformation, theoretical analysis, numerical simulation, and on‐site verification were used to study the influence of geological, mining, and support factors on the stability of the floor roadway surrounding rock. A design method for strengthening the roadway surrounding rock support was proposed. The results showed that the coal seam depth, the distribution characteristics of the remaining coal pillar load, the starting point position of stress recovery in the upper coal seam goaf and the lower coal seam goaf lateral load had a significant influence on the lower coal seam stress. The peak stress in the lower coal seam increased linearly with the increase of the coal seam depth, the remaining coal pillar, and the lower coal seam goaf lateral peak stress. The remaining coal pillar influence area width increased linearly and exponentially with the increase of the remaining coal pillar width and the distance between the starting point of stress recovery in goaf and the coal pillar edge, respectively. The peak stress and shear strength of the narrow coal pillar decreased exponentially with the increase of the spacing between bolts or cables. The roadway surrounding rock deformation decreased exponentially with the increase of the distance between the strengthening support area and the remaining coal pillar edge. For the Baigou coalmine, a design scheme for bolt strengthening support parameters has been proposed. The roadway surrounding rock deformation tended to stabilize after 21 days, with deformation values of 264 and 488 mm for the roof and floor, and two sides, respectively.

The last cave lion of the late Upper Palaeolithic: The engraved feline of Grotta Romanelli (southern Italy)

On the occasion of the review of the portable art of Grotta Romanelli, a decorated stone with a feline figure was object of an interdisciplinary study. The analysis considered different approaches so to: characterise the stratigraphic setting of the finding, the rock support, look into the techniques used to decorate the stone, elaborate a graphic documentation (photographs, 3D models and tracings), relate the symbolic production with the environmental context, and consider the motifs into the wider late Upper Palaeolithic (LUP) art production.The work allows confirming that the represented subject corresponds to a Panthera spelaea, and fixing some issues concerning the variability of the decorating activity, which is in line with the graphic tradition of the European LUP. Style and formal variable features of the figure might have responded to specific social conventions or to single author's skills, tracing new investigation lines about the cultural behaviour and the decorating activity: from the collection of the raw material and the preliminary modelling of the support, to the different artistic techniques (engraving and painting), from the use of the object to the definition of possible local artistic variations and/or inspiration at large scale. Moreover, it questions the thematic aspect in relation to the local fauna and its influence in the symbolic production, highlighting the importance of this stone in the wider debate about the extinction of the cave lions. Indeed, the Romanelli lion may represent the last evidence of this animal in Europe.

Comparative analysis of polyacrylate latex modified cement grout for water blocking and rock reinforcement with six alternative materials

Grouting plays a crucial role in mitigating water inrush disasters and reinforcing weak surrounding rock formations, and the effectiveness of grouting operations is heavily dependent on the choice of grouting materials. This study undertakes an assessment of the feasibility of deploying polyacrylate latex modified cement grouting material (PLMC) for the purposes of water obstruction and surrounding rock reinforcement, achieved through a comparative analysis against six alternative grouting materials, each of which has been applied in practical engineering. The experimental results demonstrate that the initial setting time and fluidity of PLMC fall within the range of other grouting materials, meeting the project requirements. PLMC achieves the highest filling rate at 77.42%, while the filling rates of other grouting materials range from 39.69% to 74.13%. PLMC exhibits good performance in bleeding ratio (2.77%) and resilience against dynamic scouring (retention rate is 72.95%), ranking as the third highest among the seven compared materials for both indexes. Additionally, the uniaxial compressive strengths of PLMC grout stone body and grouting-reinforced body reached 11.94 MPa and 22.74 MPa, respectively, representing the best performances. In comparison, the highest levels of these two indexes for other grouting materials are 8.78 MPa and 21.46 MPa, respectively. Compared with other grouting materials, the porosity of PLMC grout stone body is the lowest, and the interface between rock and grout in PLMC-reinforced body exhibits no significant gaps. The findings suggest that polyacrylate latex modified cement grouting material exhibits exceptional workability characteristics, positioning it as a promising candidate for practical applications.

Damage characteristics of rock induced by unloading in hole under true triaxial boundary stresses: Experimental study

In order to study the effect of unloading of underground rock excavation on the stability of surrounding rock, the true triaxial compression (TTC) and coupled true triaxial compression and in-hole loading-unloading tests (TTC-HU) were conducted on hollow cubic rock (100mm × 100mm × 100mm). The experimental results indicate that the compressive strengths of the specimens increase as confining pressure increases in the equal biaxial stressand increase with increasing intermediate principal stresses in the unequal biaxial stress. At low confining pressure (σ < 30 MPa), the internal stress at unloading damage in the hole of hollow cubic specimen increases with the increase of the three-directional boundary stresses. At high confining pressure (σ ⩾ 30 MPa), the specimen will not be damaged during the entire unloading process in the hole. The damage mode of the specimen is dominated by tensile damage. The shape of the holes in the specimens did not significant change, and hole wall of specimen have layered destruction along the circumference in low confining pressure. In high confining pressure, the hole area of the specimen undergoes significant deformation damage, forming a V-groove along the direction of the minimum principal stress, and the wall of the hole is completely peeled off. This study can reasonably predict the actual engineering damage patterns and guide the optimization of surrounding rock support.

A novel constitutive law of confined grouted rock bolt under pull-out load based on a fully nonlinear bond-slip model

Rock bolts are widely applied in deep underground excavations for rock reinforcement. Here, a constitutive model that quantifies the pull-out load-displacement relationship of the grouted rock bolt has been developed though theoretically analyzing the load transfer behaviour along the bolt-grout interface. An improved nonlinear continuously yielding criteria was employed as a bond-slip model where the role of confining pressure playing in slip was accounted. The performance of the proposed constitutive model was demonstrated by comparing with three sets of laboratory pull-out tests on the fully grouted rock bolts under different confining pressure levels (including a short-encapsulated pull-out test designed in our laboratory). The input parameters in the model were determinable within the laboratory environment. The analytical simulation results of pull-out load-displacement performance, the axial stress in the rock bolt and shear stress along the bolt-grout interface agreed well with the laboratory data. We also found that the confining pressure significantly affects the critical embedment length and the higher the confining pressure, the shorter the critical embedment length. The findings enrich the understanding on the mechanical properties of grouted rock bolts and hence aid the rock engineers in rock reinforcement design in underground excavations.

Influence of component parameters on propagation characteristics of foaming polyurethane grout in rock fractures

Polyurethane grouting is an important technical solution used for seepage prevention and mechanical reinforcement of fractured rock. Various components of polyurethane grout significantly affect the grout properties and propagation behavior. The present study focuses on the crucial role of component parameters in controlling the propagation process and designing grouting parameters for foaming polyurethane grout. A coupled modeling approach combining chemical reactions and flow field analysis is developed to investigate the polyurethane foaming process. The proposed modeling approach is validated by comparing simulation results with experimental data from the literature. The influence of key component parameters: isocyanate index, initial water concentration and physical blowing agent, on the propagation characteristics (including propagation distance, maximum pressure, final density, reaction time and maximum temperature) of foaming polyurethane grout in rock fractures are further analyzed. The results reveal two distinct types of effects caused by the components, i.e., a monotonic relationship and a parabolic trend. Critical values are identified for the impact of isocyanate index on maximum propagation distance, final density and characteristic time, as well as for the influence of physical blowing agent on maximum propagation distance, final density and maximum pressure. Other parameters demonstrated a monotonic relationship. Additionally, a quantitative assessment is conducted to evaluate the impact of multiple components on propagation characteristics. The finding indicates that the initial water concentration has a significant effect on all properties, while isocyanate index exerts a more pronounced impact on reaction time and maximum temperature. The effect of the physical blowing agent is relatively minor compared to other factors. This study is helpful for material selection and proportioning of polyurethane grout in practical engineering applications.

Rockburst risk control and mitigation in deep mining

It is important to understand and manage rockburst challenges in deep mining operations. This paper presents a systematic study of rockburst risk in underground mining, offering a detailed examination of influencing factors, risk assessment, and various control and mitigation methods. The complexities of rockburst phenomena are explained by examining factors that lead to the occurrence of rockbursts. A rockburst risk assessment using a bow-tie analysis is conducted, which provides insights into both risk evaluation and proactive control and mitigation systems.The core of the paper presents a comprehensive array of rockburst risk control and mitigation methods, which range from controls to reduce rockburst hazard, and excavation vulnerability, to controls and mitigations to reduce exposure. Strategic engineering control methods, including mine design and mining sequencing, are discussed. Tactical engineering control measures, such as ground pre-conditioning and rock support, are scrutinized, along with administrative controls like evacuation and re-entry protocols and the use of mechanized equipment. A multiple-line defense system is advocated for rockburst risk management to address the uncertainties involved in the process.Finally, emerging technologies and innovations as well as challenges are discussed, providing a roadmap for continued advancements in rockburst risk management in the future. This work serves as a valuable resource for mining professionals, researchers, and policymakers seeking a comprehensive understanding of rockburst risk management in deep mining.

Influence of advance direction on surrounding rock stability of main ramp under deep high ground stress

Due to the widespread use of trackless equipment in metal mines, the main ramp has become a major development roadway in large mines. Under deep high ground stress condition, the stability of the surrounding rock of the main ramp is subject to significant variability due to the change in the advance direction, leading to structural failure in different areas of the roadway. Because the support design scheme of surrounding rock of main ramp will not pay attention to the advance direction of roadway, leading to the key support area of the surrounding rock is not clear, resulting failure of the local supporting form occur frequently. Therefore, this paper adopts the combination of on-site investigation and numerical simulation to carry out the stability analysis of the surrounding rock under different advance directions of the roadway. Through on-site investigation, various failure modes of surrounding rock induced by the change of the advance direction of the roadway are summarized, and the key supporting area of surrounding rock of main ramp is determined according to the angle change between the roadway advance direction and the intermediate principal stress. The extent of the risk zone of the roadway surrounding rock is defined based on the Drucker-Prager criterion, which can be used as the new basis for the design of roadway support parameters. The results show that: As the angle between the advance direction and the intermediate principal stress increases, the degree of deformation of the surrounding rock decreases linearly, and the volume of the plastic and risk zones of the surrounding rock decreases nonlinearly. Based on the distribution of the strain energy density of the roadway surrounding rock, when the angle between the advance direction and the intermediate principal stress is small, the roadway surrounding rock is more prone to the floor heave phenomenon. When the angle between the advance direction and the intermediate principal stress is larger, the roadway surrounding rock is prone to the full-section failure phenomenon. Based on the block theory, when the advance direction is changed, the location and production of key blocks have significant variability, leading to the need for reasonable adjustment of the support parameters for the surrounding rock. The research results of this paper are of guiding significance for the optimization of the surrounding rock support scheme of the main ramp.