High-quality cross-boundary continuous grading support system suitable for soft coal rock roadway in complex environment

Abstract

The invention provides a high-quality cross-boundary continuous grading support system suitable for a soft coal rock roadway in a complex environment, which relates to the technical field of coal mine roadway support and comprises a first-stage foundation support system, a second-stage reinforced support system and an intelligent monitoring system, the first-stage foundation support system, the second-stage foundation support system and the third-stage foundation support system cooperate with one another to achieve continuous graded support and long-time stable control of roadway surrounding rock, and the first-stage foundation support system is used for achieving surrounding rock shallow constraint, preliminary stress release and preliminary rock mass consolidation; through continuous cooperative control of first-stage foundation support and second-stage reinforced support and application of a novel support material, rheological and swelling deformation of surrounding rock can be effectively restrained, and practical application verifies that side deformation and top deformation of a roadway are reduced, and the bulging amount of a bottom plate is controlled within safety limit values; through the design of lagging grouting full anchoring and collaborative anchoring, fractured rock mass is effectively consolidated and repaired, the stress concentration degree of surrounding rock is improved, and the problem that an existing support is poor in long-term stability is solved.

Description

Technical Field

[0001] This invention relates to the field of coal mine roadway support technology, and in particular to a high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock. Background Technology

[0002] As coal mining extends into deeper areas, roadway support is a core element in ensuring safe mining operations and improving mining efficiency. Current coal mine roadway support technologies primarily combine passive and simple active support. Common support forms include anchor-mesh cable + shotcrete support, spandrel support, and grouting reinforcement support. Among these, anchor-mesh cable support is the most widely used due to its ease of construction and moderate cost. Grouting support is mainly used in roadways with well-developed fissures and high water content in soft surrounding rock. Grouting materials fill the fissures in the surrounding rock, consolidating the fractured rock mass and improving the bearing capacity of the surrounding rock itself. Spandrel support is often used in roadway sections with extremely poor surrounding rock stability and large deformation, providing temporary or permanent rigid support. These support technologies can basically meet the support needs in shallow, moderately stable surrounding rock roadways, ensuring short-term roadway service safety.

[0003] However, for soft coal and rock roadways in complex environments, especially those with "five highs and two disturbances" characteristics in deep mining, existing support technologies have many insurmountable shortcomings, making it impossible to achieve long-term stable control of the roadway: First, the support effect is poor. Traditional support cannot effectively constrain the rheological and dilatational deformation of the surrounding rock, leading to excessive roof subsidence, sidewall bulging, and floor bulging, with deformation in some areas far exceeding safety limits, affecting the normal use of the roadway; Second, the compatibility of support materials is poor. Ordinary anchor bolts and cables experience significant degradation in mechanical properties under high stress and water immersion environments, and the consolidation strength and durability of grouting materials are insufficient, failing to meet the long-term support needs of permanent roadways; Third, the support coordination is insufficient, with the first-level... The lack of effective continuous connection between primary and secondary supports prevents the formation of an integrated support system, making it difficult to withstand the long-term effects of complex stresses. Furthermore, the construction process is imperfect, lacking effective real-time monitoring methods for the grouting process. Parameters such as grouting pressure and volume cannot be precisely controlled, making transparent management of concealed works impossible and grouting quality difficult to guarantee. Finally, the low level of intelligence means there is a lack of real-time monitoring and intelligent control of the surrounding rock condition and the stress on the support structure, making it impossible to promptly identify support hazards and optimize support schemes, resulting in persistently high roadway safety risks. Therefore, this invention proposes a high-quality cross-boundary continuous graded support system suitable for complex environments and weak coal and rock roadways to address the problems existing in the prior art. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock. This system, through continuous synergistic control of primary foundation support and secondary reinforcement support, combined with the application of novel support materials, effectively constrains the rheological and fragmentation deformation of the surrounding rock. Practical application verification shows that it reduces the deformation of the roadway sidewalls and roof, and keeps the floor bulge within safe limits. Through delayed grouting full anchoring and synergistic anchoring design, it effectively consolidates and repairs fractured rock masses, improves the stress concentration of the surrounding rock, and can meet the service life requirement of more than 20 years for permanent roadways, solving the problem of poor long-term stability of existing support systems.

[0005] To achieve the objectives of this invention, the following technical solution is provided: a high-quality cross-boundary continuous graded support system suitable for soft coal and rock roadways in complex environments, comprising a primary basic support system, a secondary reinforced support system, and an intelligent monitoring system. The three systems work together to achieve continuous graded support and long-term stability control of the roadway surrounding rock. The primary basic support system is used to achieve shallow constraint of the surrounding rock, initial stress release, and initial consolidation of the rock mass. The secondary reinforced support system is used to supplement and strengthen the primary basic support system, thereby achieving continuous and coordinated control between the two.

[0006] The intelligent monitoring system is used to monitor the condition of the surrounding rock in the roadway, the stress on the support structure, and the parameters of the grouting process in real time, providing data support for the optimization and adjustment of the support scheme.

[0007] Further improvements are made in the following aspects: The primary foundation support system includes high-strength hollow grouting anchor cables, high-rigidity lightweight multi-ribbed trays, steel mesh surface protection structures, and mining inorganic reinforced composite mortar grouting materials; the high-strength hollow grouting anchor cable rods are hollow structures used to provide foundation anchoring force and transport grouting materials; the high-rigidity lightweight multi-ribbed trays are used to disperse the anchor cable preload and enhance the surface protection effect; the steel mesh surface protection structure is used to constrain the deformation of the surrounding rock surface and prevent rock mass spalling; the mining inorganic reinforced composite mortar grouting materials are used to fill the surrounding rock fissures and consolidate the fractured rock mass.

[0008] A further improvement is made in that the grouting volume of the aforementioned inorganic reinforced composite mortar grouting material for mining is determined by the following algorithm:

[0009] ,

[0010] Where Q is the grouting volume of a single anchor cable (L), and S is the area of ​​fracture development in the surrounding rock of the grouting section of the tunnel (L). This was determined through monitoring of surrounding rock fissures; The grouting filling coefficient ranges from 1.1 to 1.3, and is determined based on the degree of fracture development. The density (kg / L) of the cured grouting material is determined by the material performance parameters. ρ is the density (kg / L) of the grouting material before it has cured, which is determined by the material performance parameters; v is the average width of the crack (m), which is determined by monitoring the cracks in the surrounding rock.

[0011] Further improvements include: the diameter of the high-strength hollow grouting anchor cable is 22-24mm; the size of the high-rigidity lightweight multi-ribbed tray is 300×300×15-18mm; the steel mesh protective structure uses Φ6-8mm steel bars with a mesh size of 80×80-100×100mm; and the strength grade of the mining inorganic reinforced composite mortar grouting material is M40-M50.

[0012] A further improvement is made in that the construction method of the primary foundation support system includes the following steps:

[0013] Timely end anchor support: After the tunnel is excavated, resin cartridges are used to achieve high-strength hollow grouting anchor cable end anchors;

[0014] Strengthen shallow constraints: Install a high-rigidity, lightweight multi-ribbed tray and a steel mesh protective structure;

[0015] Fully release stress: utilize the space of the free section of the anchor cable to relieve stress in the surrounding rock;

[0016] Delayed grouting full anchor: Grouting is performed on the free section of the anchor cable rod after a certain distance from the face, so as to achieve full-length bonded anchoring.

[0017] Further improvements are made in the following aspects: The secondary reinforced support system includes extended high-strength hollow grouting anchor cables, high-power tensioning equipment, and a collaborative anchoring structure; the length of the extended high-strength hollow grouting anchor cables is determined according to the thickness of the primary anchoring layer formed by the primary foundation support system, and is used to provide reinforced anchoring force deep into the surrounding rock; the high-power tensioning equipment is used to increase the pre-tension of the anchor cables and enhance the active restraint capability; the collaborative anchoring structure is used to achieve a tight connection between the primary and secondary supports, ensuring that the two are subjected to force collaboratively.

[0018] A further improvement is made in that the length of the extended high-strength hollow grouting anchor cable is determined by the following algorithm:

[0019] ,

[0020] Wherein, L2 is the length (m) of the secondary extended high-strength hollow grouting anchor cable, k1 is the safety factor, with a value range of 1.2-1.5, determined according to the stability level of the surrounding rock of the roadway; h1 is the thickness (m) of the primary anchoring layer, determined through on-site testing; k2 is the stress correction factor, with a value range of 0.8-1.0, determined according to the magnitude of the ground stress; The maximum principal stress (MPa) of the surrounding rock in the roadway is determined through mine pressure monitoring. The allowable stress (MPa) of the anchor rod is determined based on the properties of the anchor material.

[0021] Further improvements include: the tensioning tonnage of the high-power tensioning machine is 300-400t, the pre-tension of the extended high-strength hollow grouting anchor cable is controlled at 200-350kN, and the collaborative anchoring structure adopts rigid or flexible connectors, which are determined according to the deformation characteristics of the surrounding rock of the roadway.

[0022] A further improvement is made in that the construction method of the secondary reinforced support system includes the following steps:

[0023] Collaborative anchoring design: Based on the thickness of the primary anchoring layer and the stress distribution of the surrounding rock, the length and spacing of the secondary anchor cables are determined by algorithm;

[0024] Enhanced Anchoring Strength: Increase the number of resin cartridges and extend the anchoring length of the secondary anchor cable;

[0025] Prestressing enhancement: High-power tensioning equipment is used to increase the prestress of the anchor cables;

[0026] System coordinated control: The coordinated anchoring structure enables the primary and secondary supports to share the load, thereby further strengthening the primary anchoring layer.

[0027] Further improvements are made in that the intelligent monitoring system includes a laser rangefinder, a real-time mine pressure monitoring device for roadway surrounding rock, a roof delamination monitoring device, an anchor cable axial force monitoring system, surrounding rock fissure monitoring equipment, and a digital grouting monitoring device; each monitoring device works in concert to collect data on surrounding rock surface displacement, roof delamination amount, anchor cable axial force, surrounding rock fissure evolution, and grouting parameters, and transmits the data to the monitoring terminal for real-time display, analysis, and early warning.

[0028] The beneficial effects of this invention are as follows:

[0029] 1. This invention, through continuous and coordinated control of primary basic support and secondary reinforced support, combined with the application of new support materials, can effectively constrain the rheological and fragmentation deformation of the surrounding rock. Practical application has verified that it reduces the deformation of the roadway sidewalls and roof, and controls the floor bulging within safe limits. Through delayed grouting full anchoring and coordinated anchoring design, it effectively consolidates and repairs fractured rock mass, improves the stress concentration of the surrounding rock, and can meet the service life requirement of more than 20 years for permanent roadways, solving the problem of poor long-term stability of existing support systems.

[0030] 2. This invention establishes a rapid tunneling multi-process parallel operation mode suitable for hollow grouting anchor cable support, optimizes the time and space arrangement of grouting and anchoring processes, improves the combination of anchor cables with other support systems, achieves a high degree of synergy between support and tunneling, and significantly improves construction efficiency. By improving support quality, reducing the number of roadway repairs and material consumption, it reduces roadway maintenance and support costs, extends the service life of roadways, and further enhances the core competitiveness and economic benefits of enterprises.

[0031] 3. This invention achieves real-time monitoring and intelligent early warning of the surrounding rock condition, support structure stress, and grouting process through an intelligent monitoring system. It can promptly detect potential support hazards and optimize and adjust the support plan, effectively control roadway deformation, and reduce the occurrence of safety accidents. Through digital grouting monitoring and ledger management, it realizes transparent management of underground hidden works, establishes an intelligent control platform for roadway stability, significantly improves the safety and reliability of coal mining, and reduces the operational risks for construction personnel. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the primary support system of the present invention;

[0033] Figure 2 This is a schematic diagram of the secondary support system of the present invention;

[0034] Figure 3 This is a top view of the support scheme of the present invention;

[0035] Figure 4 This is a schematic diagram of the laser rangefinder arrangement of the present invention;

[0036] Figure 5 This is a schematic diagram of the arrangement of the anchor cable force gauge of the present invention;

[0037] Figure 6 This is a schematic diagram of the base point of the top plate delamination monitoring instrument of the present invention;

[0038] Figure 7 This is a schematic diagram of the grouting anchor cable design of the present invention. Detailed Implementation

[0039] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0040] Example 1

[0041] according to Figure 1 , 2As shown in Figures 3, 4, 5, 6, and 7, this embodiment proposes a high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock. The system includes a primary basic support system, a secondary reinforced support system, and an intelligent monitoring system. These three systems work together to achieve continuous graded support and long-term stability control of the roadway's surrounding rock. Wherein:

[0042] Primary foundation support system

[0043] As the foundational layer for roadway support, it is used to achieve shallow constraint of the surrounding rock, initial stress release, and initial consolidation of the rock mass. It includes high-strength hollow grouting anchors, high-rigidity lightweight multi-ribbed trays, steel mesh surface protection structures, and mining-grade inorganic reinforced composite mortar grouting materials. The high-strength hollow grouting anchors provide foundation anchoring force; their hollow structure facilitates the delivery of grouting materials. The high-rigidity lightweight multi-ribbed trays disperse the pre-tension of the anchors, enhancing the surface protection effect and preventing localized stress concentration in the surrounding rock. The steel mesh surface protection structure covers the surface of the roadway surrounding rock, constraining surface deformation and preventing rock spalling. The mining-grade inorganic reinforced composite mortar grouting materials fill cracks in the surrounding rock, consolidate broken rock masses, and enhance the bearing capacity of the surrounding rock itself.

[0044] Secondary reinforced support system

[0045] As a reinforcement layer for roadway support, it is used to supplement and strengthen the primary foundation support system, realize continuous and coordinated control between primary and secondary supports, and improve the overall support system's load-bearing capacity and stability. It includes extended high-strength hollow grouting anchor cables, high-power tensioning equipment, and coordinated anchoring structures. The length of the extended high-strength hollow grouting anchor cables is determined according to the thickness of the primary anchoring layer and is used to penetrate deep into the surrounding rock to provide stronger anchoring force. The high-power tensioning equipment is used to increase the pre-tension of the anchor cables and enhance the active restraint capability of the support structure. The coordinated anchoring structure is used to achieve a tight connection between the primary and secondary supports, ensuring that they are coordinated in force and continuously controlled.

[0046] Intelligent monitoring system

[0047] This system is used for real-time monitoring of the surrounding rock condition, support structure stress, and grouting process parameters in roadways. It provides data support for optimizing and adjusting support schemes, enabling intelligent management and control of roadway support. The system includes a laser rangefinder, a real-time mine pressure monitoring device for the surrounding rock, a roof delamination monitoring instrument, an anchor cable axial force monitoring system (anchor cable force gauge), surrounding rock fissure monitoring equipment, and a digital grouting monitoring device. All monitoring devices work together to collect parameters such as surrounding rock surface displacement, roof delamination amount, anchor cable axial force, surrounding rock fissure evolution, grouting pressure, and grouting volume. The data is then transmitted to the monitoring terminal for real-time display, analysis, and early warning.

[0048] Hierarchical collaborative control method

[0049] Construction method of primary foundation support

[0050] The construction process adopts "timely end anchoring - reinforced surface protection - stress release - delayed full anchoring," with the following specific steps: ① Timely end anchoring support: After tunnel excavation, high-strength hollow grouting anchor cables are quickly anchored at the ends using resin cartridges to rapidly provide foundation anchoring force and constrain initial deformation of the surrounding rock; ② Reinforced shallow constraint: After the anchor cables are anchored at the ends, a high-rigidity, lightweight multi-ribbed tray and steel mesh surface protection structure are installed to reinforce the shallow surrounding rock of the roof and sidewalls, preventing surface spalling; ③ Stress Full release: Utilizing the free section space of the high-strength hollow grouting anchor cable, the rock mass undergoes a certain degree of deformation and pressure relief under high stress, avoiding stress concentration that could lead to damage to the support structure; ④ Delayed grouting full anchor: Delaying the head by a certain distance, after the stress of the roof surrounding rock is fully released, grouting is carried out on the free section of the rod through the hollow structure of the anchor cable, so that the mineral inorganic reinforced composite mortar grouting material fills the cracks in the surrounding rock and bonds with the anchor cable rod, achieving full-length bonded anchoring of the anchor cable and further improving the anchoring effect.

[0051] Construction method of secondary reinforced support

[0052] Based on the continuous beam cross-boundary support theory, a construction process of "collaborative design - strong anchoring - prestressing reinforcement - system coordination" is adopted. The specific steps are as follows: ① Collaborative anchoring design: Based on the thickness of the primary anchoring layer, the stress distribution of the surrounding rock, and the cross-sectional dimensions of the roadway, the reasonable length and spacing of the secondary reinforcement support anchors are determined by algorithm calculation to achieve continuous collaborative control between the primary and secondary supports; ② Strong extended anchoring: The number of resin cartridges is increased to increase the anchoring length of the secondary reinforcement support anchors, ensuring that the anchors penetrate deep into the stable surrounding rock layer and improving anchoring reliability; ③ Prestressing reinforcement: High-power tensioning equipment is used to tension the secondary reinforcement support anchors, significantly increasing the anchor preload and enhancing the active constraint capacity of the support structure on the surrounding rock; ④ System coordinated control: The primary foundation support and the secondary reinforcement support are closely connected through the collaborative anchoring structure to achieve collaborative stress distribution, further strengthening the primary anchoring layer and forming an integrated support system.

[0053] Construction process optimization

[0054] Hollow grouting anchor cable construction technology

[0055] The optimized hollow grouting anchor cable construction process achieves transparent and precise control of the grouting process, specifically including: ① Real-time parameter monitoring: Through digital grouting monitoring devices, the grouting pressure, grouting volume, grouting speed, and other parameters of each grouting anchor cable are monitored in real time to ensure that the grouting parameters meet the design requirements; ② Ledger management: A grouting management ledger is established to record in detail the grouting time, grouting parameters, construction personnel, and other information for each anchor cable, achieving transparent grouting management of underground concealed works; ③ Effect diagnosis and analysis: The grouting process and effect of all underground grouting roadways are diagnosed and analyzed regularly to evaluate the grouting quality; ④ Dynamic parameter optimization: For problems such as abnormal pressure and insufficient grouting volume during the grouting process, the grouting parameters of abnormal sections are optimized and adjusted in real time to ensure the grouting effect.

[0056] Intelligent control method for roadway stability

[0057] A real-time mine pressure monitoring and intelligent analysis system for roadway surrounding rock was constructed to achieve intelligent management and control of the entire roadway support process. Specifically, this includes: ① Multi-dimensional data acquisition: Data is collected from multiple aspects, such as surrounding rock surface displacement, anchor cable axial force, roof delamination, and surrounding rock fissure evolution, through various monitoring devices of the intelligent monitoring system; ② Deep learning analysis: The collected monitoring data is analyzed and processed using deep learning algorithms to identify surrounding rock deformation patterns and potential support hazards; ③ Dynamic report generation: Dynamic mine pressure monitoring and analysis reports are generated periodically to provide data support for optimizing and adjusting support schemes; ④ Support scheme optimization: Based on monitoring results and analysis reports, the construction parameters of primary and secondary supports are adjusted and optimized in real time to ensure long-term roadway stability.

[0058] Example 2

[0059] according to Figure 1 , 2 As shown in Figures 3, 4, 5, 6, and 7, this embodiment proposes a high-quality cross-boundary continuous graded support system suitable for soft coal and rock roadways in complex environments. This system is applied to a deep soft coal and rock roadway in the Yindonggou Coal Mine. This roadway exhibits "five highs and two disturbances" characteristics: high stress (ground stress is mainly horizontal, belonging to the upper stress zone), high water content (local areas of the roadway are close to the aquifer, and the mudstone cements after fissure water is introduced), high deformation (poor long-term stability of the surrounding rock, exhibiting long-term rheological characteristics), high construction difficulty (limited worker experience, high personnel turnover, and complex equipment operation), and high safety risk (severe roadway deformation, large-scale cracking of the slurry skin in local areas, and obvious floor heave). The roadway is designed with a rectangular cross-section, with dimensions of 4.5m × 3.8m (width × height), and a service life of 25 years. The high-quality cross-boundary continuous graded support system of this invention is used for support.

[0060] Parameters of the primary foundation support system: High-strength hollow grouting anchor cable diameter 22mm, length 3.8m, spacing 1.2m×1.2m (row spacing×space); High-rigidity lightweight multi-ribbed tray dimensions 300×300×15mm; Reinforcing mesh uses... Reinforcing steel bars, mesh size 100×100mm; mining inorganic reinforced composite mortar grouting material strength grade M40, grouting pressure controlled at 1.5-2.0MPa.

[0061] Parameters of the secondary reinforced support system: The extended high-strength hollow grouting anchor cable has a diameter of 22mm and a length of 6.5m. It is arranged between the two rows of primary support anchor cables, with one row left empty and one row installed at a spacing of 2.4m × 1.2m (row spacing × spacing); the high-power tensioning machine has a tensioning tonnage of 300t, and the anchor cable pretension is controlled at 200-250kN; the coordinating anchoring structure adopts rigid connectors to achieve a tight connection between the primary and secondary anchor cables.

[0062] The intelligent monitoring system is deployed as follows: one real-time mine pressure monitoring device for the surrounding rock is deployed every 50m to monitor the displacement of the surrounding rock surface; one roof delamination monitoring instrument is deployed every 30m to monitor the amount of roof delamination; one force gauge is deployed for every 10 anchor cables to monitor the axial force of the anchor cables; one surrounding rock fissure monitoring device is deployed every 40m to monitor the evolution of surrounding rock fissures; and one digital grouting monitoring device is equipped for each grouting pump to monitor the grouting pressure and grouting volume in real time.

[0063] Construction method: Following the primary foundation support construction process, resin cartridges were immediately used to anchor the high-strength hollow grouting anchor cables at the ends after tunnel excavation. Trays and steel mesh were then installed, and full grouting anchoring was carried out 8m after the face. After the primary support construction was completed, based on the thickness of the primary anchoring layer (tested to be 3.5m), the length of the secondary anchor cable was determined to be 6.5m using an algorithm. High-power tensioning equipment was used for tensioning, and a collaborative anchoring structure was installed to achieve collaborative control. During construction, grouting parameters and surrounding rock conditions were monitored in real time, and the grouting pressure and anchor cable pretension were optimized based on the monitoring results.

[0064] Application Results: After the roadway support was completed, monitoring for one year showed that the deformation of the roadway sidewalls was 85-120mm, the deformation of the roof was 60-95mm, and the bulging of the floor was 280-350mm, all within safe limits. The grouting qualification rate reached over 98%, the surrounding rock fissures were effectively consolidated, the roadway stability was good, and the problems of severe deformation and grout cracking of the original support were completely solved, meeting the 25-year service life requirement. The construction efficiency was increased by 30% compared with traditional support, the support cost was reduced by 22%, and the accident rate was reduced to 0.

[0065] Example 3

[0066] according to Figure 1 , 2As shown in Figures 3, 4, 5, 6, and 7, this embodiment proposes a high-quality cross-boundary continuous graded support system suitable for soft coal and rock roadways in complex environments. It is applied to a deep-buried, water-soaked soft rock roadway in a coal mine. The roadway is 800m deep, with surrounding rock mainly consisting of mudstone and shale, which is severely cemented, with a water content of 18-25% and a compressive strength of only 8-12MPa. The roadway has an arched cross-section with dimensions of 5.0m × 4.2m (width × height) and a service life of 22 years. Due to water immersion and high stress, traditional support schemes have repeatedly encountered problems such as roadway deformation and support failure. The high-quality cross-boundary continuous graded support system of this invention is used for support modification.

[0067] Parameters of the primary foundation support system: High-strength hollow grouting anchor cables, diameter 24mm, length 4.2m, spacing 1.0m × 1.0m (row spacing × spacing); High-rigidity lightweight multi-ribbed tray, dimensions 320 × 320 × 16mm, rust-proof and corrosion-resistant, suitable for water immersion environments; Reinforcing mesh... Reinforcing bars with a mesh size of 80×80mm are used to enhance the strength of the protective surface. The mining inorganic reinforced composite mortar grouting material is coated with a waterproofing agent, with a strength grade of M45. The grouting pressure is controlled at 2.0-2.5MPa to ensure the consolidation effect of the grouting material in a water immersion environment.

[0068] Parameters of the secondary reinforced support system: The extended high-strength hollow grouting anchor cable has a diameter of 24mm and a length of 7.0m. It is arranged in the gap between the primary support anchor cables with a spacing of 2.0m × 1.0m (row spacing × spacing); the high-power tensioning machine has a tensioning tonnage of 350t, and the anchor cable pretension is controlled at 250-300kN; the coordinating anchoring structure adopts flexible connectors to adapt to the deformation characteristics of the surrounding rock in the water immersion environment and avoid the failure of the connectors due to corrosion.

[0069] The intelligent monitoring system is deployed as follows: One real-time mine pressure monitoring device for the surrounding rock is installed every 40m, using waterproof sensors to monitor surface displacement and moisture content; one roof delamination monitor is installed every 25m to monitor the amount of roof delamination, with a warning value set at 150mm; one waterproof force gauge is installed for every 8 anchor cables to monitor the anchor cable axial force; one surrounding rock fissure monitoring device is installed every 30m to monitor the opening and propagation rate of surrounding rock fissures; and a digital grouting monitoring device with a waterproof design monitors grouting pressure, grouting volume, and grouting concentration in real time to ensure grouting quality.

[0070] Construction Method: Targeting the characteristics of a water-immersed environment, the construction process for the primary foundation support was optimized. After tunnel excavation, waterproof resin cartridges were used for end anchoring of the anchor cables, shortening the end anchoring time to within 30 minutes of excavation to prevent accelerated softening of the surrounding rock upon contact with water. After installing the trays and steel mesh, grouting was performed 6m after the face of the tunnel. A waterproofing agent was added during the grouting process to enhance the waterproof performance of the grouting material. After the primary support was completed, the thickness of the primary anchoring layer was calculated using an algorithm (tested to be 3.8m), determining the length of the secondary anchor cables to be 7.0m. High-power tensioning equipment was used for tensioning, and a flexible, collaborative anchoring structure was installed to achieve coordinated stress distribution between the primary and secondary supports. An intelligent monitoring system monitored the water content of the surrounding rock and the grouting effect in real time. When abnormal grouting pressure was detected, the grouting concentration and pressure were adjusted promptly to ensure that the grouting material fully solidified in the water-immersed environment.

[0071] Application Results: After the roadway support renovation was completed, 18 months of monitoring showed that the roadway sidewall deformation was 75-105mm, the roof deformation was 55-85mm, and the floor bulge was 250-320mm, all meeting safety requirements. The grouting material consolidated well in the water immersion environment without loosening or falling off, and the consolidation rate of the surrounding rock fissures reached 99%. The roadway stability was significantly improved, with no support failures or excessive deformation, meeting the 22-year service life requirement. Construction efficiency was increased by 35% compared to traditional support, the support repair rate was reduced to below 1%, and the support cost was reduced by 25%, effectively solving the problem of soft rock roadway support in water immersion environments.

[0072] Example 4

[0073] according to Figure 1 , 2 As shown in Figures 3, 4, 5, 6, and 7, this embodiment proposes a high-quality cross-boundary continuous graded support system suitable for soft coal and rock roadways in complex environments. It is applied to a high-stress, fractured coal and rock roadway in a coal mine. This roadway has a depth of 750m, with ground stress reaching 35-45MPa. The surrounding rock is mainly fractured coal and rock with densely developed fissures, and the rock mass integrity coefficient is only 0.3-0.4. The roadway cross-section is rectangular, with dimensions of 4.8m × 4.0m (width × height), and a service life of 20 years. Traditional support schemes cannot withstand high stress, resulting in large roadway deformation and multiple roof collapse hazards. The high-quality cross-boundary continuous graded support system of this invention is used for support.

[0074] Parameters of the primary foundation support system: High-strength hollow grouting anchor cables with a diameter of 22mm, a length of 4.0m, and a spacing of 0.9m×0.9m (row spacing×spacing), with a denser arrangement to enhance foundation anchoring force; High-rigidity lightweight multi-ribbed trays with dimensions of 300×300×18mm, increasing tray thickness and improving load-bearing capacity; The steel mesh uses double-layer Φ6mm steel bars with a mesh size of 80×80mm to enhance surface protection and prevent spalling of fractured rock mass; The mining inorganic reinforced composite mortar grouting material contains an early-strength agent, with a strength grade of M50, and the grouting pressure is controlled at 2.5-3.0MPa to accelerate the consolidation speed of the grouting material.

[0075] Parameters of the secondary reinforced support system: Extended high-strength hollow grouting anchor cables with a diameter of 22mm and a length of 7.5m are arranged in the gaps between the primary support anchor cables at a spacing of 1.8m × 0.9m (row spacing × spacing); the high-power tensioning machine has a tensioning tonnage of 400t, and the anchor cable pretension is controlled at 300-350kN to improve the prestress level and resist high stress; the co-anchoring structure adopts high-strength rigid connectors to ensure that the primary and secondary anchor cables are subjected to force in a coordinated manner, thereby improving the overall support system's load-bearing capacity.

[0076] The intelligent monitoring system is deployed as follows: one real-time mine pressure monitoring device for the surrounding rock is installed every 30m to monitor the surface displacement and stress changes of the surrounding rock; one roof delamination monitoring instrument is installed every 20m to monitor the amount of roof delamination, with a warning value set at 120mm; one force gauge is installed for every 6 anchor cables in the anchor cable axial force monitoring system to monitor the anchor cable axial force in real time and prevent anchor cable overload failure; one surrounding rock fissure monitoring device is installed every 25m to monitor the fissure propagation rate of the surrounding rock; and a digital grouting monitoring device monitors the grouting pressure, grouting volume, and grouting speed in real time to ensure that the grouting material fully fills the broken fissures.

[0077] Construction Method: Targeting the characteristics of high-stress fractured surrounding rock, the primary foundation support adopts an optimized process of "timely end anchoring - rapid surface protection - stress release - delayed full anchoring." Immediately after tunnel excavation, resin cartridges are used to achieve end anchoring of the anchor cables, shortening the end anchoring time to within 20 minutes of excavation, quickly providing anchoring force. Double-layer steel mesh and thickened support plates are installed to strengthen surface protection constraints and prevent fractured rock spalling. Full anchoring with grouting is performed 6m after the face, with early-strength agents added to the grouting material to ensure 70% of the design strength is reached within 4 hours after grouting. After the primary support construction is completed, the thickness of the primary anchoring layer is determined by algorithm (tested to be 4.0m), and the secondary anchor cable length is 7.5m. High-power tensioning equipment is used for tensioning to ensure the pre-tension meets design requirements. A high-strength collaborative anchoring structure is installed to achieve continuous collaborative control between primary and secondary supports. An intelligent monitoring system monitors changes in ground stress and anchor cable axial force in real time. When an abnormal increase in ground stress is detected, the anchor cable pre-tension is adjusted promptly to optimize the support scheme and resist high stress.

[0078] Application Results: After the roadway support was completed, monitoring over two years showed that the roadway sidewall deformation was 70-100mm, the roof deformation was 50-80mm, and the floor bulge was 220-300mm, all within safe limits. The fractured surrounding rock was effectively consolidated, the rock mass integrity coefficient increased to over 0.7, the ground stress was evenly distributed, and no stress concentration occurred. The roadway stability was good, the risk of roof collapse was completely resolved, and the 20-year service life requirement was met. The construction efficiency was increased by 32% compared to traditional support, the support cost was reduced by 23%, and the safety and reliability were significantly improved, providing a feasible solution for the support of high-stress fractured coal and rock roadways.

[0079] Validation data:

[0080] This invention has been practically applied in various complex environments of soft coal and rock roadways. The key performance indicators of each embodiment compared with traditional support schemes are summarized in the table below, with specific data as follows:

[0081]

[0082] As can be seen from the above data, the present invention is significantly superior to traditional support schemes in terms of support effect, long-term stability, construction efficiency, economic benefits and safety performance. It can effectively adapt to the support needs of different types of complex environments and weak coal and rock roadways, and completely solves many shortcomings of existing technologies.

[0083] This invention, through continuous and coordinated control of primary basic support and secondary reinforced support, combined with the application of novel support materials, effectively constrains the rheological and dilatational deformation of the surrounding rock. Practical application verification has shown that it reduces the deformation of the roadway sidewalls and roof, and keeps the floor bulge within safe limits. Through delayed grouting and full anchoring design, it effectively consolidates and repairs fractured rock masses, improves the stress concentration of the surrounding rock, and meets the service life requirement of permanent roadways exceeding 20 years, solving the problem of poor long-term stability of existing support systems. Furthermore, this invention establishes a rapid excavation multi-process parallel operation mode suitable for hollow grouting anchor cable support, optimizes the temporal and spatial arrangement of grouting and anchoring processes, improves the combination of anchor cables with other support systems, and achieves a high degree of synergy between support and excavation, significantly improving construction efficiency. By improving support quality, reducing the number of roadway repairs and material consumption, it lowers roadway maintenance and support costs, extends the roadway's service life, and further enhances the company's core competitiveness and economic benefits. Meanwhile, this invention achieves real-time monitoring and intelligent early warning of the surrounding rock condition, support structure stress, and grouting process through an intelligent monitoring system. It can promptly detect potential support hazards and optimize and adjust the support plan, effectively control roadway deformation, and reduce the occurrence of safety accidents. Through digital grouting monitoring and ledger management, it realizes transparent management of underground hidden works, establishes an intelligent control platform for roadway stability, significantly improves the safety and reliability of coal mining, and reduces the operational risks for construction personnel.

[0084] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock, comprising a primary basic support system, a secondary reinforced support system, and an intelligent monitoring system, the three working together to achieve continuous graded support and long-term stability control of the roadway surrounding rock, characterized in that: The primary basic support system is used to achieve shallow confinement of the surrounding rock, initial stress release, and initial consolidation of the rock mass. The secondary reinforcement support system is used to supplement and strengthen the primary basic support system, so as to achieve continuous and coordinated control of the two. The intelligent monitoring system is used to monitor the condition of the surrounding rock in the roadway, the stress on the support structure, and the parameters of the grouting process in real time, providing data support for the optimization and adjustment of the support scheme.

2. The high-quality cross-boundary continuous graded support system for roadways in complex environments with weak coal and rock, as described in claim 1, is characterized in that: The primary foundation support system includes high-strength hollow grouting anchor cables, high-rigidity lightweight multi-ribbed trays, steel mesh surface protection structures, and mining-grade inorganic reinforced composite mortar grouting materials. The high-strength hollow grouting anchor cable rods are hollow structures used to provide foundation anchoring force and transport grouting materials. The high-rigidity lightweight multi-ribbed trays are used to disperse the anchor cable preload and enhance the surface protection effect. The steel mesh surface protection structure is used to constrain the deformation of the surrounding rock surface and prevent rock mass spalling. The mining-grade inorganic reinforced composite mortar grouting materials are used to fill the surrounding rock fissures and consolidate the fractured rock mass.

3. A high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock, as described in claim 2, is characterized in that: The grouting volume of the mining inorganic reinforced composite mortar grouting material is determined by the following algorithm: ， Where Q is the grouting volume of a single anchor cable (L), and S is the area of ​​fracture development in the surrounding rock of the grouting section of the tunnel (L). This was determined through monitoring of surrounding rock fissures; The grouting filling coefficient ranges from 1.1 to 1.3, and is determined based on the degree of fracture development. The density (kg / L) of the cured grouting material is determined by the material performance parameters. ρ is the density (kg / L) of the grouting material before it has cured, which is determined by the material performance parameters; v is the average width of the crack (m), which is determined by monitoring the cracks in the surrounding rock.

4. A high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock, as described in claim 3, is characterized in that: The diameter of the high-strength hollow grouting anchor cable is 22-24mm, the size of the high-rigidity lightweight multi-ribbed tray is 300×300×15-18mm, the steel mesh protective structure uses Φ6-8mm steel bars, the mesh size is 80×80-100×100mm, and the strength grade of the mining inorganic reinforced composite mortar grouting material is M40-M50.

5. A high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock, as described in claim 4, is characterized in that: The construction method of the primary foundation support system includes the following steps: Timely end anchor support: After the tunnel is excavated, resin cartridges are used to achieve high-strength hollow grouting anchor cable end anchors; Strengthen shallow constraints: Install a high-rigidity, lightweight multi-ribbed tray and a steel mesh protective structure; Fully release stress: utilize the space of the free section of the anchor cable to relieve stress in the surrounding rock; Delayed grouting full anchor: Grouting is performed on the free section of the anchor cable rod after a certain distance from the face, so as to achieve full-length bonded anchoring.

6. A high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock, as described in claim 1, is characterized in that: The secondary reinforced support system includes extended high-strength hollow grouting anchor cables, high-power tensioning equipment, and a collaborative anchoring structure. The length of the extended high-strength hollow grouting anchor cables is determined according to the thickness of the primary anchoring layer formed by the primary foundation support system, and is used to provide reinforced anchoring force deep into the surrounding rock. The high-power tensioning equipment is used to increase the preload of the anchor cables and enhance the active restraint capability. The collaborative anchoring structure is used to achieve a tight connection between the primary and secondary supports, ensuring that both are subjected to force collaboratively.

7. A high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock, as described in claim 6, is characterized in that: The length of the extended high-strength hollow grouting anchor cable is determined by the following algorithm: ， Wherein, L2 is the length (m) of the secondary extended high-strength hollow grouting anchor cable, k1 is the safety factor, with a value range of 1.2-1.5, determined according to the stability level of the surrounding rock of the roadway; h1 is the thickness (m) of the primary anchoring layer, determined through on-site testing; k2 is the stress correction factor, with a value range of 0.8-1.0, determined according to the magnitude of the ground stress; The maximum principal stress (MPa) of the surrounding rock in the roadway is determined through mine pressure monitoring. The allowable stress (MPa) of the anchor rod is determined based on the properties of the anchor material.

8. A high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock, as described in claim 7, is characterized in that: The tensioning capacity of the high-power tensioning machine is 300-400t, the pre-tension of the extended high-strength hollow grouting anchor cable is controlled at 200-350kN, and the collaborative anchoring structure adopts rigid or flexible connectors, which are determined according to the deformation characteristics of the surrounding rock of the roadway.

9. A high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock, as described in claim 8, is characterized in that: The construction method of the secondary reinforced support system includes the following steps: Collaborative anchoring design: Based on the thickness of the primary anchoring layer and the stress distribution of the surrounding rock, the length and spacing of the secondary anchor cables are determined by algorithm; Enhanced Anchoring Strength: Increase the number of resin cartridges and extend the anchoring length of the secondary anchor cable; Prestressing enhancement: High-power tensioning equipment is used to increase the prestress of the anchor cables; System coordinated control: The coordinated anchoring structure enables the primary and secondary supports to share the load, thereby further strengthening the primary anchoring layer.

10. A high-quality cross-boundary continuous graded support system suitable for roadways in complex environments with weak coal and rock, as described in claim 1, characterized in that: The intelligent monitoring system includes a laser rangefinder, a real-time mine pressure monitoring device for roadway surrounding rock, a roof delamination monitoring device, an anchor cable axial force monitoring system, surrounding rock fracture monitoring equipment, and a digital grouting monitoring device. The various monitoring devices work together to collect data on the displacement of the surrounding rock surface, the amount of delamination of the roof, the axial force of the anchor cables, the evolution of the surrounding rock fractures, and grouting parameters. The data is then transmitted to the monitoring terminal for real-time display, analysis, and early warning.

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