Grouting Time Research Articles

The grouting plugging mechanism of layered jointed rock mass considering the time-varying yield stress of grout

Slurry retention in fractures decreases after grouting is completed and the pressure supply is stopped, which affects the grouting sealing effect and prevents or restrains the occurrence of such adverse conditions. Based on the time-varying yield stress of grout, a theoretical analysis model of grouting diffusion decay is established, the decay height variation function and the minimum pressure stabilisation time calculation formula are derived, and the sealing mechanism of a jointed rock mass with multiple joints is studied. Moreover, a 3D visualisation laboratory test device for grouting diffusion decay of a jointed rock mass with layers was developed to analyse the diffusion and decay process of grout with different water-cement (W/C) ratios visually, and the correctness of the theoretical model was verified. The results show that: (1) the W/C ratio of grout should not be greater than 2, otherwise it is difficult for grout to remain in the cracks; (2) a large fissure opening easily spreads grout but is not conducive to the retention of grout; and (3) the time of stable pressure determines the retention rate of the slurry in the crack. When the horizontal crack opening width is 3 mm and the W/C ratio of the slurry is 1, the minimum stable pressure time to achieve a better sealing effect is 810 s. The research results can be used to reasonably plan the grouting time and improve the grouting efficiency to ensure the grouting effect, which is crucial for improving the theoretical system of grouting technology.

Diffusion properties and cementitious characteristics of ultrafine cement slurry in coral sand

Investigating the infiltration, diffusion and permeation of cement grouting materials in coral sand and the effects of grouting reinforcement measures can provide scientific support for coral sand foundation treatment, building settlement adjustment, and coastal geological disaster prevention and control. Permeation grouting tests were conducted on coral sand, and the effects of the water–cement ratio (w/c), permeability coefficient of coral sand (PCCS), and grouting pressure on the diffusion distance of the slurry, uniaxial compressive strength (UCS), and relative permeability coefficient (RPC) of the grouting cementitious body were analysed. In addition, the change trends in the slurry diffusion distance and slurry pressure was described, and the characteristics of the grouting cementitious body were analysed from three perspectives: UCS, RPC, and microstructure. The results showed that the slurry pressure increases nonlinearly with increasing grouting time and decreases nonlinearly with increasing slurry diffusion distance; additionally, UCS decreases with increasing slurry diffusion distance, with an “S”-shaped curve that is first concave and then convex, with an inflection point near L = 50 cm.

Disturbance characteristics test about double-line shield tunnel excavation in grouting-reinforced water-rich sand stratum

To study the disturbance characteristics of double-line shield tunnel excavation on sand bodies in grouting-reinforced water-rich sand stratum, a similar model test was carried out. Firstly, the physical parameters and strength indexes of the overlying soil strata of the tunnel in the water-rich sand stratum were determined by laboratory tests. The similar soil and tunnel support structures of each stratum were prepared. Then, considering the different seepage modes of upper and lower soil strata under the influence range of tunnel excavation, the model test of double-line shield tunnel excavation in a grouting-reinforced water-rich sand stratum is conducted. The variation rules of sand deformation, surface settlement, and sand body stress during the excavation of a double-line shield tunnel are analyzed utilizing monitoring and analyzing systems such as a flowmeter, micro earth pressure sensors, and dial indicators. It is found that during the excavation of the double-line tunnel, the self-stabilization ability of the grouting reinforced sand bodies is strong under the action of stable seepage. Under the influence of grouting reinforcement, the seepage path around the tunnel structure will change, the fluid-solid coupling effect will decrease, and the sand stratum will be uplifted to varying degrees. The sand body will change its mechanical properties due to the influence of seepage. The fluid-solid interaction effect will be enhanced. The fluid-solid coupling effect of soil particles and water will be further enhanced when the excavation of the subsequent tunnel is carried out. The effect of unsaturated seepage in the overlying soil stratum leads to greater stress at the arch waist of the arch tunnel. In the actual construction process, the grouting amount and grouting time should be strictly controlled. The tunnel basement is supported by anchor spray support to prevent the tunnel structure and surface uplift.

Development of transparent soil grouting test system and its application in grouted gravel pile

To visualize the grouting process of grouted gravel piles, a transparent soil model test system was developed. This system allows for the study of soil movement around the piles during grouting reinforcement and enables load-bearing capacity testing after grout solidification into piles. The experimental system comprises a grouting system, a vertical load-bearing capacity testing system, a continuous physical field measurement system, and a model box. The grouting system facilitates sequential processes: pre-consolidation, constant-pressure grouting, and vertical loading. In transparent clay with a pre-consolidation pressure of 60 kPa, constant-pressure grouting and vertical load-bearing tests for grouted gravel piles were conducted. The results captured the disturbance deformation of the soil around the pile during both grouting and vertical loading. The study indicates that disturbance deformation of the soil surrounding the pile increases with prolonged grouting time. Soil beneath the pile end predominantly undergoes vertical compression, while soil at the pile sides experiences horizontal compression. The mid-section of the soil adjacent to the pile displays oblique upward bulging and vertical deformation. Under constant-pressure grouting, the filling rate of gravel voids in the pile hole by epoxy resin chemical grout with strong time-dependent viscosity shows a decreasing trend. During vertical loading, the displacement of the soil around the pile is significantly greater than that at the pile end. Consequently, this test system facilitates the visualization and simulation of grouting and vertical load-bearing tests for grouted gravel piles.

Numerical analysis of MICP treated sand based on bio-chemo-hydro model.

Microbially Induced Calcite Precipitation (MICP) represents an environmentally friendly and innovative soil grouting technology. Involving intricate biochemical processes, it poses challenges for a thorough investigation of factors influencing microbial grouting effectiveness through experimentation alone. Consequently, A three-dimensional numerical model was developed to predict the permeability of bio-grouting in porous media. The numerical model is validated by comparing its results with test results available in the literature. The validated model is then used to investigate the effects of variation bacterial solution concentration, cementation solution concentration, grouting rate and grouting time on grouting effectiveness. It was founded that the remediation effect was positively correlated with the bacterial solution concentration and the number of grouting. An increased grouting rate enhanced the transport efficiency of reactants. Additionally, the concentration of cementation solution exhibited no significant effect on the reduction of calcium carbonate yield and permeability.

Study on key grouting blocking parameters of gas drainage boreholes in soft coal seams

The construction of gas extraction boreholes in soft coal seams is prone to collapse and deformation, and grouting reinforcement is one of the main methods to solve the problem of efficient sealing. However, the reasonable selection of key grouting parameters still needs further research. In response to the problem of selecting grouting sealing parameters for gas drainage drilling in soft coal seams, based on the “concentric ring” reinforcement sealing technology obtained in previous research, the key parameters and sealing technology of the “concentric ring” reinforcement were studied through theoretical calculation and numerical simulation experiments. The slurry diffusion morphology and range under different grouting pressures and grouting time slurry viscosity were obtained. Finally, in order to explore the application effect of key grouting parameters, on-site industrial tests were conducted in a soft and high gas coal seam. The research results indicate that the optimal grouting pressure for the “retaining wall rock hole ring” should not be less than 3 MPa, the reasonable grouting time should be 10–15 min, and the water material ratio of the grouting material should be greater than 1:1; The use of new reinforcement sealing and grouting technology can ensure long-term good extraction effect. Compared to the testing of drilling sealing effect using ordinary cloth bags with two plugs and one injection, The adoption of new reinforcement sealing technology can effectively prevent the deformation and collapse of the borehole before sealing, and due to two rounds of grouting and pre reinforcement of fractured coal, the sealing effect of the borehole is also relatively good. The research results have important theoretical value for guiding the drilling and sealing grouting engineering of gas extraction in soft coal seams.

Study on instability mechanism of soft rock roadway and pressure-relief bolt-grouting support technology

Aiming at the engineering problem of roadway deformation and instability of swelling soft rock widely existed in Kailuan mining area, the mineral composition and microstructure of such soft rock were obtained by conducting scanning electron microscopy, X-ray diffraction experiments, uniaxial and conventional triaxial tests, and the law of softening and expanding of such soft rock and the failure mechanism of surrounding rock were identified. The combined support scheme of multi-level anchor bolt, bottom corner pressure relief and fractional grouting is proposed. The roadway supporting parameters are adjusted and optimized by FLAC3D numerical simulation, and three supporting methods of multi-layer anchor bolt, bottom corner pressure relief and fractional grouting are determined and their parameters are optimized. The study results show that: the total amount of clay minerals is 53–75%, pores, fissures, nanoscale and micron layer gaps are developed, providing a penetrating channel for water infiltration to soften the surrounding rock; the three-level anchor pressure-relief and grouting support technology can control the sinking amount of the roof within 170 mm, the bottom drum amount within 210 mm, the bolts of each level is evenly distributed in tension, and the maximum stress and bottom drum displacement in the pressure relief area are significantly reduced; the pressure-relief groove promotes the development of bottom corner cracks, accelerates the secondary distribution of peripheral stress, and weakens the effect of high stress on the shallow area. Using time or displacement as the index, optimizing the grouting time, filling the primary and excavation cracks, blocking the expansion and softening effect of water on the rock mass, realizing the dynamic unity of structural yielding pressure and surrounding rock modification, has guiding significance for the support control of soft rock roadway.

Diffusion mechanism of solid waste product utilization pulping and fracture network grouting

China's commitment to achieving carbon neutrality by 2060 has highlighted the pressing need for effective solid waste recycling. The reinforcement of mine water hazards has led to increased production costs due to the significant consumption of slurry. This study focuses on the development of mine crack grouting sealing and reinforcement materials using mine slag powder and waste rubber particles, along with cement reinforcement and alkali slag stimulation. The impact of water-cement ratio, rubber particle content, and slag mass fraction on slurry performance is analyzed, and the optimal values for these parameters are determined. A two-phase seepage simulation using COMSOL is conducted to investigate the flow and diffusion of slurry in a fractured network rock mass. The findings indicate that a water-cement ratio of 0.7 and a slag and rubber particle mass fraction of 70% and 30% respectively result in the slurry with favorable fluidity and mechanical properties. The diffusion pattern of the slurry in the fractured rock mass is characterized by vortex-like diffusion. The stability of the fractured rock mass is influenced by both grouting time and pressure, which should be carefully considered during on-site operations. This research has significant implications for the integrated prevention and control of mine water hazards and the large-scale utilization of high-dosage solid waste, thereby ensuring production safety, ecological environment safety, and sustainable development in mining areas.

Grouting anchor cable active advanced support technology for mining roadways

Because of the deficiencies in safety and economy of the single hydraulic prop passive advanced support, the grouting anchor cable active advanced support technology is proposed with the Changping Coal Mine 53,081 roadway as the engineering background. By using a combination of theoretical analysis, laboratory tests, numerical simulation, and field tests, the influence of different grouting parameters on the diffusion law of grout is studied. Considering the effect of the stress field on grout migration, a grout seepage-stress coupling model is established. Grouting material ratio tests are carried out and grout parameters are tested. The grouting part of the advanced grouting anchor cable is modeled and solved using the COMSOL Multiphysics numerical software. The results show that the grouting material selected is Portland cement 42.5 and water glass double liquid grout, with a slurry ratio of 15% ACZ-1 type additive and 4% water glass content, and a water–cement ratio of 0.6. The grouting pressure for the 53,081 roadway grouting anchor cable advanced support is 5 MPa, the grouting time is 6 min, and the grouting anchor cable spacing is 2000 mm × 1000 mm. The engineering application shows that the maximum roof subsidence is 180 mm, the maximum separation value at a depth of 9 m is 24 mm, and the maximum separation value at a depth of 3 m is 90 mm. The research results have achieved effective advanced support for the 53,081 roadway, replacing the single hydraulic prop, and provided a theoretical basis for the subsequent design of advanced support parameters for mining roadways.

Study on the mechanism and simulation of slurry diffusion in fractured rock mass based on detour effect

The grout diffusion law and grouting effect of fractured rock mass are affected by the roundabout effect. In this paper, based on the power law fluid theory, the formula of slurry diffusion mechanism in fractured rock mass considering the circuitous effect is derived; Further, based on COMSOL numerical simulation software, the influence of grouting pressure and grouting time on the slurry diffusion range is studied; Finally, through comparative analysis, the correctness and feasibility of the theoretical analysis are verified based on the numerical simulation results. The research results can provide theoretical reference and technical support for the design and construction of grouting engineering.

Experimental study on bio-treatment effect of the dredged Yellow River silt based on soybean urease induced calcium carbonate precipitation

As the river with highest silt content in the world, the Yellow River is dredged annually to relieve the pressure of flood control. Prior studies indicated that the dredged Yellow River silt cannot be directly utilized as construction filling material because of the deficiency in strength and stability. In this study, soybean urease induced calcium carbonate precipitation (SICP) method was proposed to solidify the Yellow River silt for the purpose of promoting its mechanical properties. The influences of soybean powder concentration and pH value on the soybean urease activity were investigated. By estimating the urease activity of per unit mass, the soybean powder concentration with highest extraction efficiency were determined. The optimum bio-treatment recipe including cement solution concentration and grouting time of the biological solidification agent suitable for the Yellow River silt was characterized through unconfined compressive strength (UCS) test and CaCO3 content test. Meanwhile, scanning electron microscope (SEM) and X-ray diffraction (XRD) analysis of the bio-treated Yellow River silt sample verified the effectiveness of solidification from microscopic viewpoint. The findings of this study suggest that soybean urease induced calcium carbonate precipitation (SICP) method can effectively improve the geotechnical engineering properties of Yellow River silt and provide a technical approach for the resource utilization of the Yellow River silt.

Tidal Effect on Grouting and Blocking of Flowing Water in Karst Fractures: Numerical Implementation and Its Application

The issue of water blocking by grouting in coastal areas has engendered the need for a novel numerical simulation method for grouting with a flowing water under tidal action, two-fluid tracking (TFT). This paper proposes such a method. First, based on the material derivative, the transport model of the residence time of injected slurry was derived. In addition, the residence time of injected slurry microgroups at any grouting time was obtained by solving the transport model. Further, the numerical characterization of slurry viscosity during grouting in flowing water was realized by introducing a time-varying viscosity function obtained from previous experiments. Then, based on the generalized tidal action model, the diffusion behavior and blocking mechanism of slurry under tidal effects were studied. The results show that: (1) under tidal action, the water velocity fluctuates and decreases, whereas the grouting pressure fluctuates and increases; (2) at the early stage of grouting, the diffusion pattern of slurry appears as a droplet, and the tailing phenomenon becomes more serious with an increase of tidal intensity; with the progress of grouting, the diffusion pattern gradually changes to U-shaped or elliptical; (3) the strong tidal action will reduce the retention rate of slurry, which is not conducive to the grouting blocking. The research results have been applied to the grouting treatment of a China Resources Cement (Hepu) limestone mine. This research can provide some useful guidance for grouting treatment engineering of water inflow in coastal areas.

Research on spatiotemporal evolution law of surrounding rock fractures and hierarchical collaborative control technology in high-stress soft rock roadway: A case study

Safe and efficient coal mining has always been restrained in high-stress roadways due to their highly rheological property and large-scale deformation, which are key technical problems to be solved in this industry. In this work, the high-stress roadway of Wuju Coal Mine in Gansu, China is taken as the engineering background. First, long-term field tracking survey was conducted on the cracks of the surrounding rock during excavation to quantitatively analyze the spatial-temporal evolution law. Meanwhile, using the principle of simplicity, the variation trends of radial and axial permeability were revealed and the optimal grouting time in this roadway was determined. We proposed the theory of anchor grouting support with fixed anchor length, as well as hierarchical collaborative control technology (HCCT). The high-strength hollow grouting cables and corresponding anchor-grouting methods were also investigated and identified, which addresses the long-standing technical contradiction between grouting support and pressure deformation. Engineering test proves that this new technology can realize the safe and efficient control of high-stress rock roadway, with the maximum crack depth on the roof reduced from 7.65 m to 3.10 m and the surrounding rock deformation decreased by more than 56%. This paper provides new ideas for the maintenance and control of rock roadways or tunneling projects in similar conditions.

Study on the Parameters of Strengthening Soft Surrounding Rock by Electric Pulse Grouting in the Mining Face

As an effective measure for the rapid fracturing of coal and rock, electric pulse fracture technology has been successfully applied in oil extraction and natural gas discharge. Using the electric pulse fracture mechanism, this technology can be applied to grouting reinforcement to improve the infiltration efficiency of grouting. In this study, we used a numerical simulation method to establish numerical models with different electric pulse peak pressures, different grouting times and different drilling spacing conditions Through numerical simulation studies, we found that the influence range of grouting reinforcement grows with the increased maximum pressure generated by the electrical pulse. The most economical and reasonable electric pulse parameter setting is 5 MPa for static grouting pressure and 100 MPa for peak electric pulse pressure. The best grouting time to keep pressure in the borehole is determined as 9 h, and the best borehole interval is 10 m. In addition, through the treatment of the soft roof of the Caojiashan coal mine, we also found that the reinforcement sample within the grouting reinforcement range had a compressive strength of more than 1.1 MPa; after each grouting reinforcement was completed, the hydraulic bracket could advance 12 m each time, which shows that the electric pulse grouting reinforcement technology has an obvious effect on the treatment of soft roof slab.

Analysis of the diffusion range of the sleeve valve pipe permeation grouting column-hemispheric under the variation of the permeability of porous media

<abstract> <p>Grouting is widely used to solve problems such as water inrush and collapse in tunnels and subways, with permeation grouting being the most common method. This study explores the influence of fluid flow resistance on the permeability of porous media and derives an analytic expression for the variation of permeability in porous media based on the diffusion law of cement-based grout columns-hemispherical diffusion. Based on this, a Newtonian fluid permeation grouting column-hemispherical diffusion model considering the variation of permeability in porous media is established, combining the rheological equation and the equilibrium equation of the Newtonian fluid. The theoretical results considering the influence of fluid flow resistance on the permeability of porous media are consistent with the results of existing laboratory tests and numerical simulations, which are closer to the experimental results, thus verifying the effectiveness of the proposed theoretical mechanism. Parameter analysis shows that with the increase of grouting pressure and grouting time, the diffusion radius of the Newtonian fluid infiltration grouting, considering the variation of permeability in porous media, increases rapidly and then increases slowly, and with the increase of porous media porosity, its radius decreases gradually. The research results can provide theoretical support for selecting grouting parameters and quality control in porous media infiltration grouting engineering practice.</p> </abstract>

Research on reuse of silty fine sand in backfill grouting material and optimization of backfill grouting material proportions

Silty fine sand is a common muck in shallow urban tunnels, and the reuse of on-site muck resources is an urgent need in the field of shield tunneling. A shield tunneling section of Nanjing Metro Line 7 in a silty fine sand formation was analyzed in this paper. Combined with SPSS multiple regression analysis and MATLAB multiobjective planning tools, X-ray diffraction technology and laboratory tests were used to optimize the ratio of muck grouting liquid. The feasibility of silty fine sand as a substitute sand source for backfill grouting liquid was discussed. Based on actual conditions, the influences of grout performance and grouting parameters on the diffusion of the grouting liquid in the seepage stage were studied. The effectiveness of the muck grout was verified by monitoring values such as surface settlement and segment uplift in the field test. The results showed that silty fine sand can be used as the sand source for preparing grouting liquid that meets the requirements of on-site construction through the addition of a water-reducing agent and by optimizing the ratio. The grouting liquid with the best performance has advantages in terms of 7 d and 28 d strength, bleeding rate, and cementation strength. The stability of this grouting liquid is good, and 44.6% of costs can be saved; the cost-optimized ratio grouting liquid has advantages in 7 d strength and economic benefit, and 74.6% of costs can be saved. However, the stability of this grouting liquid is poor. Under the same grouting time, the pressure generated by the muck grouting liquid and the field grouting liquid on the unit area of the segment is close.

Study on the Influence of Back-fill Grouting Parameters in Unsaturated Strata on the Seismic Performance of Shield Tunnels

In this study, based on unsaturated soil theory, the diffusion behavior of shield tunnel back-fill grouting in unsaturated strata was considered, and Van Genuchten equation was introduced for deriving calculation formula for grouting diffusion radius. Then, an analysis flow for the influence of back-fill grouting parameters on seismic performance of shield tunnel was proposed, and the analysis was carried out with an actual project example. The results show that, compared to the saturated state, owing to the existence of matrix suction in the unsaturated soil, the permeability of the stratum is reduced, resulting in a slower increase in the grouting diffusion radius and smaller ultimate grouting distance. In this project, after using asphalt-cement grouting material, increasing the grouting time and grouting pressure, as well as reducing the elastic modulus of the material can decrease the seismic response of the tunnel. When the grouting time t = 60 min, grouting pressure P0 = 0.5 MPa, elastic modulus E = 49.1 MPa, the seismic-reduction rate of the structure can reach 25.65%. Finally, the fitted equations for the grouting time, pressure, and elastic modulus of the grouting material with the relative displacement and seismic-reduction rate of the tunnel were obtained.

Numerical Study on Seepage of Chemical Grout Flow in Rock Fracture under Temperature Field

Grouting technology is widely used to improve the mechanical properties and reduce the permeability of the rock in underground engineering. Fluidity is important to promote the grout to be injected into longer fractures, so chemical grouts with low viscosity and adjustable gel time are usually chosen to increase this property. However, the high temperature in some deep engineering leads to a faster hydration rate of the chemical grout than that in the room temperature environment, resulting in the decrease of fluidity. The heat exchange between the grout and the environment is usually ignored in the existing researches, so the aim of the numerical study is therefore to analyse the seepage process of chemical grout in the temperature field, where heat exchange between the grout and environment is considered. A sandstone model with a fracture is established in COMSOL, which is validated using laboratory experiments to confirm the accuracy of the results. The grouting time rises exponentially with the increasing of the flow distance in a single fracture, and a higher environmental temperature leads to a larger grouting time because the gap in the viscosity of the grout at different temperatures enlarges with the increasing hydration time. The effect of the temperature field on the grouting time becomes more significant when the temperature is higher and the hydration time is longer because the viscosity of the grout rises more slowly. The grouting time reduces dramatically when injection pressure is raised because an increasing pressure results in a larger aperture and less hydration time, which is one of the best ways to improve the efficiency of the grouting. The findings of this study can help for better understanding of the seepage process of chemical grout in fractures under high temperature and provide guidance for the selection of chemical grout in grouting engineering.

A Case Study on Surrounding Rock Deformation Control Technology of Gob-Side Coal-Rock Roadway in Inclined Coal Seam of a Mine in Guizhou, China

Surrounding rock deformation control of gob-side coal-rock roadway in inclined coal seams (GCRICS) is a major problem in gob-side entry technology application practice. This paper describes a case study of the surrounding rock deformation characteristics and control technology of a typical GCRICS in Guizhou, China. As according to data obtained during a field investigation, the reasons for the deformation and failure of 151509 tailentry and the shortcomings of the original support scheme were analyzed. In combination with existing theory and field experience, the “anchor cable + U-shaped steel + shotcreting + grouting” (CUSG) support method was proposed. The plastic zone distribution, displacement, and stress evolution law of the roadway-surrounding rock under the four support modes were analyzed and compared by numerical simulation. The results show that the supporting effects of several support methods varied from good to poor; CUSG was the best, followed by anchor cable support, U-shaped steel support, and then no support. Based on the previous seepage grouting theory, a slurry diffusion model of hollow grouted anchor cable (HGC) was established and the calculation formulas of slurry diffusion radius and grouting time were deduced, which provided guidance for field construction. Finally, the CUSG surrounding rock control technology was applied to 151509 tailentry subsequent roadway support. Through drill holes, analysis of the surrounding rock of the non-grouting area and the grouting area was conducted. It was found that the surrounding rock of the grouting area was high in integrity and strong in bearing capacity. Throughout the excavation period to the end of roadway mining, the roadway did not have to be repaired. This case study has high practicability, high popularization value, and provides a useful reference for the engineering support design of the GCRICS.

Real-time characterization of the grouting diffusion process in fractured sandstone based on the low-field nuclear magnetic resonance technique

Investigations of the flow and diffusion mechanism of grout slurry in underground fractured rock mass are of critical significance to guarantee the grouting reinforcement of deep soft rock tunnel and to ensure the construction safety. This paper reports a series of permeation grouting tests in fractured sandstone samples based on the low-field nuclear magnetic resonance (LF-NMR) technique. During the grouting process, the NMR signal characteristics of the grout were monitored in real-time, and the parameters such as the slurry injection volume, effective grouting time and grout filling speed were comprehensively analyzed under various temperatures, confining pressures, flow velocities and numbers of fractures. The results show that the final injection amount of the grout decreases with increasing temperature and confining pressure. The effective grouting time is inversely proportional to the flow velocity, while it is positively related to the temperature. The filling speed decreases with increasing the temperature and confining pressure, while it increases with increasing the grout flow velocity. Compared to the single fractured sample, the sample with more fractures is injected with more grout slurry in a shorter effective grouting time and a higher filling speed. Under the conditions of high confining pressure (e.g., 15 MPa) or high flow velocity (e.g., ≥5 ml/min), the grout slurry preferentially transports into the micropores, and then the mesopores and macropores. However, the temperature and number of fractures have equal effects on the grout flow and diffusion in the three types of pores. The grouting filling performance becomes worse when the temperature and confining pressure are higher. The findings in this study provide meaningful guidance for the grouting reinforcement of deep soft rock tunnel.