Ground Pressure Research Articles

A new experimental method of one single lining with airbag resistance limiter support for large deformation

Soft rock tunnels with high ground pressure will experience significant deformation of the surrounding rock. In order to improve the stability of soft rock tunnel excavation with significant ground stress, it is essential to study new high-performance tunnel lining materials. This research aims to introduce a new method of one single lining with airbag resistance limiter support to solve large deformation. For the first time, we used a novel energy-absorbing inflatable airbag resistance limiter. The composite structure of “rock + airbag resistance limiter + rigid support” is adopted in this study. In the experimental scheme circular tunnel lining model is divided into two cases: Case 1, rigid support, and Case 2, rigid support with a one-layer airbag resistance limiter. The test results indicate the following; (1) the rigid support with airbag limiter support effectively controls the large deformation of surrounding rock, and the deformation control ability of Case 2 is better than that of Case 1. (2) The contact pressure in both cases increases by imposing load, comparing with Case 2, surrounding rock pressure of Case 1 is greater. (3) The longitudinal strain of the three different sections in Case 2 was significantly reduced compared to the ordinary lining of Case 1. Additionally, the maximum lateral compression strain of Case 2 was significantly reduced to 23.3 % of Case 1. The test results indicate that the rigid support with an airbag resistance limiter support is better than the rigid support without an airbag in terms of crack resistance, stability, effectiveness, and deformation control capability. However, the study results indicate that the proposed method using the new support technology of an inflatable airbag resistance limiter is feasible and effective. The integrity and safety of the resistance limiter are guaranteed, the airbag is easy to obtain, the processing is convenient, and its structure is simple and user-friendly. The airbag resistance limiter is an economical, efficient, and safe supporting structure.

Numerical study on the dynamic pressure control for self-forming roadways using CHRCT in thin coal seams with thick and hard roofs

Close-hole roof-cutting technology (CHRCT, also called “dense drilling”) has been widely applied in coal mines due to its economic and safety benefits. Inappropriate cutting parameters and support schemes can lead to dynamic pressure disturbances in self-forming roadways with thick and hard roofs. Moreover, fully characterizing the procedure and process of self-forming roadways using CHRCT in the field is difficult, resulting in unconvincing results. Therefore, this study aims to fill the gaps in theoretical knowledge and methodology. First, the dynamic pressure characteristics of the self-forming roadway using CHRCT were investigated, and the dynamic pressure types of the roadway were classified. There are three main types: roof cut off along the coal wall side of, severe deformation, and overhanging roof of a roadway after the second working face mining. The effects of different hole parameters (inclination angle, depth and spacing) on the roof cutting to form a roadway were also investigated. The optimal hole inclination, depth and spacing of 15°, 8 m, and 200 mm were determined through a series of experiments. Then, three support schemes embedded in the roadway were compared in terms of stress evolution, bolt and cable axial forces, roof displacement, and structure. Finally, this study proposes a dynamic pressure mitigation strategy through the optimization of parameters for close-hole roof-cutting and support schemes, monitoring and controlling ground pressure in roadways, and taking auxiliary measures for pressure relief. The results show that this strategy can effectively eliminate the dynamic pressure of the roadway and meet the stability requirements of the full mining cycle. This paper presents a methodology for analysing CHRCT via numerical simulation. Moreover, this approach is of great theoretical and practical importance for dynamic pressure control for self-forming roadways using CHRCT in thin coal seams with thick and hard roofs.

Research on the Movement of Overlying Strata in Shallow Coal Seams with High Mining Heights and Ultralong Working Faces

To study the roof movement and ground pressure evolution characteristics of an ultralong working face in a shallow coal seam with a high mining height, the Shangwan Coal Mine in the Shendong mining area was used as the research background, and the physical and mechanical parameters of the surrounding rock were determined through rock mechanics experiments. A physical simulation model was built considering the 7 m mining height of the 12301 fully mechanized working face of the Shangwan Coal Mine to simulate and study the evolutions of the movement, fracture and collapse of the coal seam, direct roof, and basic roof and overlying strata during the mining process. The mechanical characteristics of the support, mechanism of roof collapse, and changes in the working resistance of the support were analysed and simulated. The research results indicate that when mining at a height of 7 m, the direct roof and basic roof strata collapse in layers; the basic roof strata collapse backwards, the rock block arrangement is more irregular, and the range of the basic roof that can form structural rock layers extends higher. After the basic roof rock fractures, it cannot form a masonry beam structure and can only form a cantilever beam structure. The periodic fracture of the cantilever beam causes periodic pressure on the working face. These research results are of great significance for planning the further mining of shallow coal seams with high mining heights and ultralong working faces in the Shendong mining area, as well as for improving the control of overlying strata.

Deformation and Failure Evolution Law and Support Optimization of Gob-Side Entry in Weakly Cemented Soft Rock under the Influence of Fault

Under the condition of weakly cemented soft rock in Western China, the surrounding rock deformation of gob-side entry is obvious, especially under the influence of fault, and the problem of surrounding rock control becomes increasingly prominent. To solve this issue, this paper firstly studied and obtained the evolution law of the ground pressure appearance of the gob-side entry in the fault area, then put forward the concept of surrounding rock control in the fault area of the gob-side entry, put forward a targeted pressure relief + increase preload + passive reinforcement parallel to the roadway surrounding rock strengthening control scheme, and carried out field applications. The results show that the roof subsidence and mining side heave of the roadway in the fault area increase significantly, accompanied by the characteristics of broken cables, the length of the broken cable is 0.2 m–0.6 m, and the breaking process is divided into multiple breaks. The stress evolution of gob-side entry in fault area presents a stage characteristic of “rapid growth-stable.” The surrounding rock control effect is improved under the bolt cable high pre-tightening support, and the roadway deformation is effectively controlled under the pressure relief + active + passive support, with a good application effect.

Ground fracturing of multi-strata for strong ground pressure control in extra-thick coal seams with hard roofs: Numerical simulation and case study

Strong ground pressure in the mining field is the key factor restricting safe mining of hard-roof mining areas. A hard roof combines high strength with a large breakage step, and the large breakage area would easily cause ground pressure disasters in the working face with gradual breakage of multi-hard rock strata. The study investigated the characteristics of the dynamic hazards under multi-hard rock strata conditions. The method of graded ground fracturing of multi-hard rock strata was proposed to control the ground pressure, and the characteristics of the bending strain energy release of the rock strata breakage and instability under the condition of equivalently decreasing the thickness of the strata by ground fracturing were theoretically analyzed. A numerical simulation model of weakening in multi-strata rock formations by fracturing was established, and the structural characteristics of rock strata breakage under the ground fracturing effects were analyzed. The results showed that the breakage characteristics of the overlying hard roofs were altered by ground fracturing, the bearing properties of the fractured rock strata were drastically reduced, while the effect of the breakage and destabilization of the rock strata was subsequently weakened. The ground fracturing practice of the L1 and L2 hard rock strata in the Tashan Coal Mine, China, taken as a case study, revealed that the cracks extension length reached approximately 220 m, and the crack’s width was 30 ∼ 120 m. During the working face was mined in the area covered by the cracks, the average supports resistance was reduced by 21 %, the rate of rib spalling was reduced by 23 %, greatly alleviating the intensity of ground pressure in the working face. The application of ground fracturing technology to multi-hard rock strata effectively weakened the hard rock strata, improving the ability of ground pressure control.

Mechanical Behavior of a Double-Layer Supported Large-Span Tunnel Excavated in Squeezing Rocks Employing Stress Release Technology

When excavating a large-span tunnel in squeezing rock, the tunnel support is subjected to significant loads. Therefore, the support structure must have enough stiffness and strength to withstand the pressure exerted by the ground. Various stress relief techniques can be used to reduce the ground pressure acting on the support and utilize the bearing capacity of the surrounding rock. One such technique is Deformation Reserved (DR). It involves reserving space outside the excavation boundary or between the two support layers. The proposed solution for the interaction between the double-layer tunnel support and the surrounding rock takes into account the excavation process and stress relief. The expressions for stress and deformation of the tunnel support and surrounding rock are provided in an elastoplastic solution. Parametric studies were conducted to investigate the effectiveness of a double-layer support structure with stress relief techniques. The monitoring data from the Lianchengshan Tunnel were compared with the proposed analytical solution. The results indicate that a larger reserved deformation behind the outer layer support is much more beneficial to tunnel stability when the total reserved deformation is constant. The ground pressure will be significantly reduced, thereby decreasing the force on the inner layer support.

An autonomous stair climbing method for the crawler robot based on a hybrid reinforcement learning controller

In response to problems in using deep reinforcement learning to perform the stair climbing task for the crawler robot, such as the lack of theoretical values for stair size range, the inaccurate force on the model using wheel to simulate track and difficulty in training, we propose an autonomous stair climbing method for the crawler robot based on a hybrid reinforcement learning controller. We propose a dynamics parameter settings method for fast simulation model by studying the distribution model of the ground pressure of the track, which improves the accuracy of the force on the fast simulation model in the stair climbing task. Our method calculates the climbing ability of the crawler robot by studying the kinematics and dynamics models of the real crawler robot in each stage of the stair climbing task, and combining with the control flow of the hybrid reinforcement learning controller. Further, we develop the training course of the hybrid reinforcement learning controller. The agent is trained in ROS-Gazebo. The course reduces the impact of poor trajectory on training, achieves higher success rates and faster convergence speed compared to random training, and effectively improves the generalization ability of the strategy.

Development and validation of sloped ground pressure prediction model for a tracked tractor in hilly and mountainous environments

Tracked tractors are better suited for agricultural production in hilly environments because of their excellent stability and flotation. The ground pressure in these environments is highly irregular owing to the ground slope, which has led to a lack of theoretical foundation and data support for the development of hillside tracked tractors (HTTs). Therefore, accurate prediction of the ground pressure at the track-soil interface on inclined terrain is important. In this study, sloped ground pressure prediction model composed of sloped terrain soil pressure-sinkage model was developed to analyse the distribution characteristics of the ground pressure of tracked tractors in agricultural operations on hillside slopes. Considering the influence of the slope angle, soil conditions, operating conditions, and important parameters of the tracked tractors (including mass, centre of gravity, and track gauge), the ground pressure prediction model used harmonic oscillator functions and peak-valley control primitive functions. To validate the proposed model, ground pressure tests of the experimental tracked tractor were conducted at different slope angles and operating conditions in an experimental platform integrating a "soil-machine-crop" system. The results showed that the maximum error between the predicted results and the test data under various slopes and operating conditions was approximately 6.3%, with an average error of approximately 4.7%; the consistency between the test results and the simulated results indicate that the model established in this study is accurate and credible. Based on the ground pressure model, the developed tractive performance prediction model for HTTs had high prediction accuracy for the slip rate and traction force in the climbing traction test. The developed theoretical model and results provide practical guidance for the structural design of advanced HTTs and manoeuvrability optimization.

Stability of longwall face adjacent to gateroads

Longwall is the widely used mining method in the word and in Vietnam due to the high production and high level of safety. To maintain production as scheduled, the stability of a longwall face is of great importance, especially at areas adjacent to gateroads where ground pressure is strongly concentrated. This paper presents a study on the stability of longwall faces adjacent to gateroads under medium and hard-to-cave roofs. By using theoretical and field measurement methods, the authors conclude that in such geological conditions, the ground pressure at face adjacent to gateroads increases and decreases cyclically. At the study site, the ground pressure fluctuates in the range of 20÷26 MPa, and the piston chainage changes in the range of 0.6÷0.9 m. The face stability is closely related to ground pressure and roof stability. The study demonstrates that the face area near tailgate appears to be less stable compared to that near maingate, and initial signs of roof weighting can occur. The paper’s results serve as fundamental science assisting mining engineers in better identifying longwall face stability, from which effective prevention and remedy measures can be developed.

Theoretical analysis and numerical simulation analysis of energy distribution characteristics of surrounding rocks of roadways

Energy is the driving force for the failure of rock materials, and the deformation and failure of the surrounding rock of the roadway is the result of energy accumulation, dissipation and release. Based on the theory of elastic-plastic mechanics and the law of energy conservation, the total energy, elastic strain energy, dissipation energy and release energy of the surrounding rock of the roadway are deduced and analyzed, and the relationship between the energy of all the components is revealed. The energy model is developed based on the Fish language embedded in FLAC3D, and the rationality and accuracy of the energy model are verified through elastic and elastic-plastic theoretical analysis; Through the practical engineering application of the energy model, the similarities and differences in the energy calculation results of the surrounding rock of the roadway through the Mohr Coulomb and Mohr-Coulomb strain softening constitutive models are revealed, and it is pointed out that it is more in line with engineering practices to consider the post-peak deterioration of the mechanical parameters of rock. The energy evolution model of the roadway is established, revealing the space-time effect of energy distribution of the surrounding rock of the roadway under different excavation speeds and conditions, and proposing the time lag of energy evolution and the peak circle effect of the elastic strain energy related to rock burst disaster. The research results can provide references for the research of disasters such as impact ground pressure and large deformation of soft rock, and provide some theoretical guidance for the supporting design of the roadway with large deformation of the surrounding rock and impact danger.

The Distribution Law of Ground Stress Field in Yingcheng Coal Mine Based on Rhino Surface Modeling

The distribution law of the ground stress field is of great significance in guiding the design of coal mine roadway alignment, determining the parameters of roadway support, and preventing and controlling the impact of ground pressure in coal mines. A geostress inversion method combining Rhino surface modeling and FLAC3D 6.0 numerical simulation software is proposed. Based on the geological data of the coal mine and the results of on-site measurements, a three-dimensional geological model of Yingcheng Coal Mine is established for the geostress inversion, and the distribution law of the geostress field in Yingcheng Coal Mine is obtained. Research shows the following: (1) The horizontal maximum principal stress values of the Yingcheng Mine are between 33.9 and 35.3 MPa, the horizontal minimum principal stress values are between 23.6 and 25.4 MPa, and the direction of the horizontal maximum principal stress is roughly in the southwest to west direction; (2) the three-way principal stress magnitude relationship is σH > σv > σh, indicating that the horizontal stress dominates in the study area, which belongs to the slip-type stress state; (3) The maximum principal stress of No. 3 coal seam is 33.1–34.8 MPa, the middle principal stress is 27.5–29.2 MPa, and the minimum principal stress is 17.3–22.9 MPa. Due to the influence of topography and burial depth, there is a phenomenon of stress concentration in some areas. By comparing the inversion values with the measured values, the accuracy of the geostress inversion is high, and the initial geostress inversion method based on Rhino surface modeling accurately inverts the geostress distribution pattern of the Yingcheng coal mine.

Experimental study on the impact of “IDS + JFCS” complex wetting agent on the characteristics of coal bodies

As China's coal mines have transitioned to deep mining, the ground stress within the coal seams has progressively increased, resulting in reduced permeability and poor wetting ability of conventional wetting agents. Consequently, these agents have become inadequate in fulfilling the requirements for preventing washouts during deep mining operations. In response to the aforementioned challenges, a solution was proposed to address the issues by formulating a composite wetting agent. This composite wetting agent combines a conventional surfactant with a chelating agent called tetrasodium iminodisuccinate (IDS). By conducting a meticulous screening of surfactant monomer solutions, the ideal formulation for the composite wetting agent was determined by combining the monomer surfactant with IDS. Extensive testing, encompassing evaluations of the composite solution's apparent strain, contact angle measurements, and alterations in the oxygenated functional groups on the coal surface, led to the identification of the optimal composition. This composition consisted of IDS serving as the chelating agent and fatty alcohol polyoxyethylene ether (JFCS).Subsequent assessment of the physical and mechanical performance of the coal briquettes treated with the composite wetting agent revealed notable enhancements. These findings signify significant advancements in the field and hold promising implications. Following the application of the composite wetting agent, notable reductions were observed in the dry basis ash and dry basis full sulfur of coal. Additionally, the water content within the coal mass increased significantly, leading to a substantial enhancement in the wetting effect of the coal body. This enhanced wetting effect effectively mitigated the coal body’s inclination towards impact, thereby offering technical support for optimizing water injection into coal seams and preventing as well as treating impact ground pressure.

Advantages of aluminum as a structural material for an agricultural robotic truck

With the development of the trend towards robot facilitation of farmers’ work, the need for their most effective implementation in the agricultural sector (including horticulture) becomes more urgent. In materials science and agricultural freight robotics, there is still no univocal opinion on what structural materials are most preferable based on technical, economic, and environmental criteria. Authors rarely relate the capabilities of structural materials for robots to a decrease in specific ground pressure. Engineering needs studies comparing different structural materials most suitable to produce agricultural load-carrying robots. This article aims to conduct a comparative investigation of three variants for an agricultural robotic truck with a steel, aluminum, or fiberglass body to justify the most acceptable material. Aluminum was hypothesized to be superior to steel and fiberglass as an agricultural freight robot material. Three robot versions were constructed using steel, aluminum, or fiberglass. They were then tested under field conditions, and the obtained results were recorded. In economic terms, using fi berglass is more justifi ed than aluminum. This is explained by the reduction in robot operating costs due to the lower density of fiberglass (1,900 versus 2,700 kg/m3). However, in terms of the environmental criterion, fiberglass loses because it contains formaldehyde and is difficult to recycle.

Evaluation of Ground Pressure, Bearing Capacity, and Sinkage in Rigid-Flexible Tracked Vehicles on Characterized Terrain in Laboratory Conditions.

Trafficability gives tracked vehicles adaptability, stability, and propulsion for various purposes, including deep-sea research in rough terrain. Terrain characteristics affect tracked vehicle mobility. This paper investigates the soil mechanical interaction dynamics between rubber-tracked vehicles and sedimental soils through controlled laboratory-simulated experiments. Focusing on Bentonite and Diatom sedimental soils, which possess distinct shear properties from typical land soils, the study employs innovative user-written subroutines to characterize mechanical models linked to the RecurDyn simulation environment. The experiment is centered around a dual-tracked crawler, which in itself represents a fully independent vehicle. A new three-dimensional multi-body dynamic simulation model of the tracked vehicle is developed, integrating the moist terrain's mechanical model. Simulations assess the vehicle's trafficability and performance, revealing optimal slip ratios for maximum traction force. Additionally, a mathematical model evaluates the vehicle's tractive trafficability based on slip ratio and primary design parameters. The study offers valuable insights and a practical simulation modeling approach for assessing trafficability, predicting locomotion, optimizing design, and controlling the motion of tracked vehicles across diverse moist terrain conditions. The focus is on the critical factors influencing the mobility of tracked vehicles, precisely the sinkage speed and its relationship with pressure. The study introduces a rubber-tracked vehicle, pressure, and moisture sensors to monitor pressure sinkage and moisture, evaluating cohesive soils (Bentonite/Diatom) in combination with sand and gravel mixtures. Findings reveal that higher moisture content in Bentonite correlates with increased track slippage and sinkage, contrasting with Diatom's notable compaction and sinkage characteristics. This research enhances precision in terrain assessment, improves tracked vehicle design, and advances terrain mechanics comprehension for off-road exploration, offering valuable insights for vehicle design practices and exploration endeavors.

Principle and practice of hydraulic softening top-cutting and pressure relief technology in weakly cemented strata

Extremely thick and hard roofs are difficult to break in the mining of a working face, and the large area of the suspended roof easily induces a strong ground pressure or dynamic impact disasters. The roof control of a coal mining face in a mine in western China was taken as a case study. The mineral composition, microstructure, and hydrophysical properties of the hard roof overlying the coal seam were analyzed. The characteristics of the weak-cementation strata that are prone to mud and collapse when encountering water were targeted to investigate the hydraulic softening roof-cutting and pressure relief technology. It was found that the clay mineral composition in the roof plate accounts for 60.6%. After 24 h of natural immersion, the rock strength decreased by approximately 10.3%–49%, and further immersion caused disintegration. By arranging high and low double-row water injection softening drilling holes in the cutting hole and roadway of the working face, the strength of roof rock strata in the target area was reduced, and the initial weighting step distance and weighting strength of the working face were reduced. The hydraulic softening roof-cutting pressure relief technology effectively regulated the weighting step distance of the hard roof and the peak weighting of the working face.

Finite strain elastic visco-plastic consolidation model for layered soils with vertical drain considering self-weight loading and nonlinear creep

Prefabricated vertical drains (PVDs) combined with vacuum and/or surcharge loading have been widely adopted to improve the strength of soft soils. Precise consolidation analysis is the theoretical basis for the design of preloading method with PVD. Current consolidation theories for layered soils with PVD seldom consider the influence of large strain, nonlinear creep, and self-weight loading simultaneously. This paper, thus, presents a finite strain elastic visco-plastic consolidation model, called RCS-EVP, for radial consolidation of layered soils with PVD. RCS-EVP is developed based on the piecewise-linear method. It takes into account nonlinear creep with limit creep strain, variable boundary conditions, anisotropy of soil hydraulic conductivity, and variable compressibility and hydraulic conductivity during the consolidation under self-weight, time-dependent surcharge and/or vacuum loading. The performance of RCS-EVP is evaluated by comparing with the results from finite element simulations and a laboratory physical model test. The variations of settlement and pore pressure of a soft soil ground improved by vacuum preloading with PVD are estimated using RCS-EVP. The results indicate that RCS-EVP provides good estimates of long-term consolidation of layered soils with PVD under both laboratory and in-situ conditions.

Parameter optimization and tractive performance evaluation of tracked miner

Enhancing the traction performance of the tracked miner is crucial for ensuring smooth seabed operation. In this study, an experimental device for the interaction between track and deep-sea sediments was designed, aligning with the walking process of the tracked miner. The primary and secondary order of the influence of the driving parameters on the mechanical properties of the undisturbed deep-sea sediments was determined by an orthogonal test, and the pressure-sinkage model and shear stress–displacement model were constructed. Building upon the shear model and the vehicle ground mechanics theory, the driving mechanics model of the tracked miner in the seabed environment was derived, and the track structure and parameter optimization method were proposed. The results show that the experimental factors significantly influence the mechanical properties of undisturbed deep-sea sediments, with the order of influence being grounding pressure > grouser height > shear rate > track shoe length > track shoe width; By optimizing the structural parameters of the “Kunlong 500” tracked miner, the drawbar pull increased by 29.1%, and the sinkage depth reduced by 12.8%. This study quantitatively analyzes the influence of structural parameters in driving performance on the sinkage and shear characteristics of deep-sea sediments, and proposes a new method for optimizing the tractive parameters. It provides new insights for achieving efficient and environmentally friendly movement of tracked miner on the seabed.

Element-scale pullout test study on the mechanical behavior of grouted anchor–soil interface subjected to ground pressure

Element-scale pullout test study on the mechanical behavior of grouted anchor–soil interface subjected to ground pressure

Investigating the Mechanism of Strong Roof Weighting and Support Resistance Near Main Withdrawal Roadway in Large-Height Mining Face

Abstract Aiming at investigating the strong roof weighting when the large height mining face is nearing the main withdrawal roadway, the 52,304 working face (WF) nearly through the main withdrawal roadway mining in a colliery of Shendong coalfield was taken as the research background. The ground pressure, roof structure, and superposition effect of stress in the last mining stage were studied by field measurement, physical simulation, and numerical calculations. The obtained results demonstrated that the main roof formed the “long step voussoir beam” structure under the influence of the main withdrawal roadway. The superposition effect of the front abutment pressure of the WF and the concentrated stress of the main withdrawal roadway caused the stress asymmetrical distribution on the two sides -level hard rock straof the main withdrawal roadway, and the stability of the pillar on the mining side decreases. The initial average periodic weighting interval was 20.7 m. While the WF approaches the main withdrawal roadway, the pillar near the WF of the main withdrawal roadway collapsed, the main roof was broken ahead of the WF, and the actual roof control distance of support and the periodic weighting interval increased by 2.56 and 1.26 times the normal state, respectively. Consequently, the “static load” of the immediate roof and the “dynamic load” of the sliding unsteadiness of the long step voussoir beam increased. The structural model of the “long step voussoir beam” under the superposition of “static and dynamic load” was established concerning those results, and an expression was proposed to compute the support resistance. Meanwhile, the mechanism of strong roof weighting was revealed when the WF was nearly through the main withdrawal roadway. The research conclusion is expected to provide a guideline for the safe withdrawal of the large-height mining faces under similar conditions.

Influence of Hydraulic Distribution Pattern on the Rock Slope Stability under Block Toppling Failure

In this paper, an analytical model for the stability analysis of rock slope subjected to block toppling pertaining to different hydraulic forms has been developed. In the traditional analytical model, ground water pressure is considered to be varied hydrostatically. To better reflect the physical situation, three different hydraulics forms have been considered in developing a stability model for a rock slope susceptible to block toppling. It is well known fact that presence of ground water causes the instability in a rock slope. The present study observes that hydraulic distribution forms also significantly influence the stability of the rock slope. Ground water pressure markedly increases the toppling forces on the blocks and reduces the normal and shear force at the base of block along failure plane, thereby causing instability. The increase in toppling force and reduction in the factor of safety on the blocks are more prominent when the flow slit is blocked, indicating a condition of permanent or seasonal frozen strata. The study highlights that adopting the traditional hydraulic form to analyse block toppling stability, considering presence of ground water would not be suitable for all field conditions. This necessitates the selection of an appropriate hydraulic distribution form based on the encountered field conditions.