Liquid Grouting Research Articles

Experimental study on the performance of shield tunnel tail grout in ground

Shield tail grouting is an important measure to control tunnelling-induced ground deformation by injecting prepared grouting materials to fill the tail gap. The working performance of grout is usually invisible and hard to obtain in construction. This paper carries out an experimental study to investigate the tail grout behavior in ground. In the current research, a testing device is developed to explore the grout behavior in varying soils. The grout working performance is evaluated not only by the liquid grout properties such as fluidity, consistency, bleeding rate, stone rate and compressed deformation but also solid grout properties such as unconfined compressive strength and permeability. Three typical grouts are chosen and their behaviors in the various soils are observed. To take an insight on the behaviors, scanning electron microscopy and mercury intrusion porosimetry analysis are employed. The microstructure of solid grout is a sign of its working performance. The observation shows that the solid grout micro-structure is influenced by grout proportions, pressure, and ground permeabilities. The experimental results are applied in the case of Beijing Metro Line 12 for validation and as a result, the ground movement is inhibited due to high performance of tail grout.

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.

Analysis of Grouting Technology in Building Construction

The application of grouting technology in housing construction is to inject liquid grout into the cavities and cracks of housing construction. After it solidifies, the stability of housing construction can be improved. Grouting technology is not only very convenient but is also environmental-friendly, and it is relatively low-cost. Therefore, it is widely used in housing construction. In this paper, the types of grouting technology and its application advantages in housing construction are analyzed, and specific application strategies are put forward, in hopes of improving the quality of housing construction.

Preparation and Properties of Double Liquid Grouting Materials (DLGMs) Used for the Regenerated Roof of a Coal Mine

Double liquid grouting materials (DLGMs) are composed of slurry A and slurry B. In response to the need for sustainable development, there is currently a focus on improving the utilization rate of resources. In this paper, industrial solid waste fly ash, slag, and ordinary Portland cement were used to prepare slurry A, while sodium silicate was used as slurry B. Slurry C was made by adding slurry B to slurry A. The mix design parameters of the DLGMs, with large amounts of fly ash, were optimized based on the response surface method. The results showed that the relative content of cement and the reactivity and morphological effect of supplementary cementitious materials (fly ash and slag) were the main factors affecting the operable time, viscosity, and stability of slurry A. The relative content of cement and the sodium silicate modulus were the main factors affecting the operable time of the DLGMs. Compared to the C30F70S0-Z3.3 group (where C, F, S, and Z represented cement, fly ash, slag, and sodium silicate modulus, respectively), the operable time of the C0F70S30-Z3.3 group increased by approximately 36 min. As the sodium silicate modulus was lowered to 2.3, the operable time of the C0F70S30-Z2.3 group increased by about 32 min compared to that of the C30F70S0-Z2.3 group. The established model and response surface can well reflect the influence of multiple factors on the properties of the DLGMs. When the mass ratio of cement/fly ash/slag in slurry A was 7.5%: 70%: 22.5%, and the sodium silicate modulus and content of slurry B were 2.8 and 10%, respectively, the 28-day compressive strength of the DLGMs can reach up to 11.3 MPa. The content of fly ash was the most significant factor affecting the 28-day compressive strength of the DLGMs, followed by the sodium silicate content. The least influential factor was the sodium silicate modulus. The XRD and SEM results showed that a large amount of Ca2+ produced by cement hydration can quickly react with [SiO4]4- in sodium silicate to form C-S-H gel. Moreover, it also promoted the hydration of C3S and C2S in grouting to produce more C-S-H gel, which was conducive to the alkali activation of slag and fly ash, resulting in a denser microstructure and hence, yielded obvious increases in the compressive strengths of the DLGMs.

Effects of sodium sulfate and potassium sulfate on the properties of calcium sulfoaluminate (CSA) cement based grouting materials

CSA cement is usually used in grouting materials because of its fast setting and high early strength properties. This paper focuses on the effects of sodium sulfate and potassium sulfate on the hydration mechanism and properties of calcium sulfoaluminate (CSA) cement based double liquid grouting materials (DLGM). A comprehensive experimental program including XRD, TG-DTA, hydration heat, scanning electron microscope (SEM) and mechanical tests were performed. The results show that both sodium sulfate and potassium sulfate accelerated the hydration of CSA cement and the formation of ettringite from the very beginning and shortened the initial and final setting time of DLGM. The changing behaviors of setting time, hydration heat and strength of DLGM with sodium sulfate and potassium sulfate were found to be different and their optimum contents were also different. The microstructure observation shows that the addition of sodium sulfate made the ettringite merged as plate-like, and potassium sulfate generated longer ettringite strips stacked together in DLGM. By considering both setting time and compressive strength, the recommended adding amounts of sodium sulfate and potassium sulfate are 3% and 1.5%, respectively. These findings could contribute to the adjustment of physical properties of DLGM.

ANALYSIS OF THE FILTRATION PROBLEM BY BITWISE SEARCH METHOD

During the construction of ground and underground structures, filtration of a liquid grout in loose soil makes it possible to strengthen the foundation and create underground waterproof partitions. A one-dimensional problem of filtering a bidisperse suspension in a homogeneous porous medium with size-exclusion particle capture mechanism is considered. The article is devoted to the calculation of the exact solution of the problem given as the upper limit of the integral with a singularity. The proposed bitwise search method for calculating integrals makes it possible to smooth out fluctuations of the solution near the singularity. Partial and total retention profiles are analyzed.

FILTRATION PROBLEM WITH NONLINEAR FILTRATION AND CONCENTRATION FUNCTIONS

ncient architectural buildings are of great value for all modern humanity. Over time, under the influence of vibrations, water and other man-made and natural factors, the foundations of such buildings are destroyed, the soil structure changes. Currently, one of the most popular methods of strengthening soils and strengthening foundations is the jet grouting technology. When the liquid grout passes through the porous rock, the suspended particles of the grout form a deposit. In this paper, we study a one-dimensional model of suspension deep bed filtration in a porous medium with different particle capture mechanisms. The considered filtration model consists of the balance equation for the masses of suspended and retained particles and the kinetic equation for deposit growth. In this case, the deposit growth rate is determined by the concentration function of suspended particles, which, in turn, depends on the properties of the suspension and the geometry of the porous medium. The solution to the problem is obtained for linear and non-linear concentration functions. An asymptotic solution of the problem is constructed for both types of functions near the concentration front of suspended and retained particles. It is shown that the asymptotic and numerical solutions are close over a long time interval.

ASYMPTOTICS OF THE FILTRATION PROBLEM WITH ALMOST CONSTANT COEFFICIENTS

During the construction of hydraulic and underground structures, a grout solution is pumped into the ground to create waterproof partitions. The liquid grout is filtered in the porous rock and clogs the pores when hardened. The mathematical model of deep bed filtration describes the transfer of suspension particles and colloids by a fluid flow through the pores of a rock. For a one-dimensional filtration problem in a homogeneous porous medium with almost constant coefficients, an asymptotic solution is constructed. The asymptotics is compared with the numerical solution.

Global asymptotics of particle transport in porous medium

Particle transport in a porous medium occurs in environmental, chemical and industrial technologies. The transport of suspended concrete grains in a liquid grout through porous soil is used in construction industry to strengthen foundations. When particles are transported by a fluid flow in a porous medium, some particles are retained in the pores and form a deposit. The aim of the work is the construction and study of a one-dimensional mathematical model of particle transport and retention in the porous medium, taking into account the simultaneous action of several particle capture mechanisms. The model consists of mass balance equation and the kinetic equation of deposit growth. The deposit growth rate is proportional to the filtration function of the retained particles concentration, and the nonlinear concentration function, which depends on the concentration of suspended particles. The use of a new parameter, depending on the distance to the porous medium inlet allows to construct a global asymptotic solution in the entire area of the mathematical model. Asymptotics is obtained as a series in two small parameters. The global asymptotics is close to the numerical solution at all points of the porous medium at any time.

Effects of Aluminum Sulfate and Quicklime/Fluorgypsum Ratio on the Properties of Calcium Sulfoaluminate (CSA) Cement-Based Double Liquid Grouting Materials.

Grouting materials are used frequently in grouting reinforcement projects, such as mining and coastal engineering. Double liquid grouting materials are mostly used because of the fast setting and high early strength properties when the two slurries are mixed together but high fluidity when the two slurries are separated. In our study, double liquid grouting materials were developed from CSA cement (slurry A), quicklime and fluorgypsum (slurry B). Aluminum sulfate was added in slurry B in order to counteract any adverse effects caused by the fluorgypsum, such as the decreased early compressive strength and the prolonged setting time. The effects of aluminum sulfate content and the quicklime/fluorgypsum ratio on the setting time, hydration heat, and compressive strength of the double liquid grouting materials were investigated, and the hydration products were characterized through thermogravimetry-differential thermal analysis (TG-DTA), X-ray Diffraction (XRD), and Scanning Electron Microscope (SEM) tests. The results show that the addition of aluminum sulfate can shorten the setting time and increase compressive strength at both early and later ages. Considering the setting time and compressive strength of double liquid grouting material at the same time, the optimum content of aluminum sulfate was found to be 2%, and the optimum ratio of quicklime/fluorgypsum was found to be 2:8. The values of the optimum content of aluminum sulfate and ratio of quicklime/fluorgypsum were verified from theoretical analysis.

Global asymptotics of filtration in porous media

Filtration problems are actual for the design of underground structures and foundations, strengthening of loose soil and construction of watertight walls in the porous rock. A liquid grout pumped under pressure penetrates deep into the porous rock. Solid particles of the suspension retained in the pores, strengthen the loose soil and create watertight partitions. The aim of the study is to construct an explicit analytical solution of the filtration problem. A one-dimensional model of deep bed filtration of a monodisperse suspension in a homogeneous porous medium with size-exclusion mechanism of particles retention is considered. Solid particles are freely transferred by the carrier fluid through large pores and get stuck in the throats of small pores. The mathematical model of deep bed filtration includes the mass balance equation for suspended and retained particles and the kinetic equation for the deposit growth. The model describes the movement of concentrations front of suspended and retained particles in an empty porous medium. Behind the concentrations front, solid particles are transported by a carrier fluid, accompanied by the formation of a deposit. The complex model has no explicit exact solution. To construct the asymptotic solution in explicit form, methods of nonlinear asymptotic analysis are used. The new coordinate transformation allows to obtain a parameter that is small at all points of the porous sample at any time. In this paper, a global asymptotic solution of the filtration problem is constructed using a new small parameter. Numerical calculations are performed for a nonlinear filtration coefficient found experimentally. Calculations confirm the closeness of the asymptotics to the solution in the entire filtration domain. For a nonlinear filtration coefficient, the asymptotics is closer to the numerical solution than the exact solution of the problem with a linear coefficient. The analytical solution obtained in the paper can be used to analyze solutions of problems of underground fluid mechanics and fine-tune laboratory experiments.

Model of grout filtration in a porous soil

To strengthen the foundations and protect them from ground water, liquid grout is pumped under pressure into a loose porous soil. Modern construction techniques use colloids or suspensions which form a waterproof layer upon solidification. Calculation of grout distribution in a porous soil is an important part of designing buildings and structures. The distribution of suspended particulates in unconsolidated soil is described by mathematical equations of particles filtration in the porous media. The aim of this work is modelling of suspended particles transport and deposit formation in a porous soil for different filtration modes. The distributions of solid particles of different sizes transported by the carrier fluid and retained on the frame of the porous medium at different kinetic rates of deposit growth are examined. Model of one-dimensional filtration with size-exclusion particle retention mechanism includes a hyperbolic system of the first order differential equations with inconsistent initial and boundary conditions that leads to discontinuous solutions. A modified mathematical model for polydisperse media with the competition between particles of different sizes for small pores is considered. The computational scheme for numerical solutions is constructed by finite difference method. Optimization methods to improve convergence and reduce computation time are used. A multi-particle model of grout filtration in a porous soil is constructed, considering the variety of sizes of suspended particles. A numerical calculation of the problem is performed for various blocking filtration coefficient. Solutions are obtained with a discontinuity on the concentration front. Approbation of the obtained numerical solutions is carried out. Plots of the suspended and retained particles concentrations depending on time and coordinates are constructed. A new model of multi-particle transport in a porous medium widely extends the design capabilities of waterproof underground walls. The solution of the filtration problem for solid particles of different sizes makes it possible to calculate the optimal composition of grout for constructing a waterproof layer in a porous soil. The developed computing finite-difference methods allow to obtain the numerical solution of complex systems of equations with good accuracy and a moderate amount of computation.

Performance and hydration study of ultra-fine sulfoaluminate cement-based double liquid grouting material

This paper prepared a novel double liquid grouting material (ultra-fine sulfoaluminate cement-based grouting material). Slurry A was composed of ultra-fine sulfoaluminate clinker, and slurry B was made from ultra-fine anhydrite and ultra-fine quicklime in accordance with a certain proportion. The properties and hydration process of the double liquid grouting material were studied in the process of adding quicklime from 0wt.% to 30wt.%, and the double liquid grouting material was studied with micro-calorimeter, thermal-thermogravimetric (DTA-TG) analysis, scanning electron microscopy and energy spectrum technique (SEM-DES), marsh cone flow time, setting time, compressive strength and expansion/shrinkage tests. The results showed that the double liquid slurry had a short setting time when quicklime was added, causing the rapid development of mechanical strength. The more the quicklime content, the longer the flow time of slurry B. The early expansion ratio increased gradually with the increase of the quicklime content. The DTA-TG and SEM-DES test results indicated that the ettringite and aluminum hydroxide are the main hydration products. And the research also found that the mechanical strength of the double liquid grouting material not only depended on the ettringite concentration, but the aluminum hydroxide content was another important influence factor.

Ultrasonically enhanced physical properties of cement grout

The use of ultrasound to enhance the physical properties of cement grout was investigated with a series of laboratory tests. Test conditions included power and duration of sonic energy and curing time. Results indicated that the use of ultrasound in the grout mixing process significantly enhanced the uniaxial compressive strength. A visible decrease in the viscosity of liquid grout was also observed. The degree of enhancement varied with sonication energy, treatment time, and curing duration.

Forward Horizontal Grouting Technology of Subway Station Ends

Guangzhou Metro Line 6 the 8th tender Tianhe Station tunnel shielding meet hole body fissure water is abundant, tunnel soil mass disintegrates easily when water permeate, consolidating with end-advancing horizontal grouting technique. By reasonable choice construction equipment, drilling location, double liquid grouting parameters to control the construction process, enhance process monitoring, get a good reinforcement effect; analyzed the prospects of the construction method.

Effect of Dilution and Contaminants on Sand Grouted with Colloidal Silica

Colloidal silica is a low-viscosity chemical grout. Samples of grouted sand were made by pouring sand into liquid grout in molds, with the grout diluted to concentrations ranging from 5 to 27% silica by weight. The unconfined compressive strength of the grouted sand, measured after 7 days, was proportional to the silica concentration, up to a maximum of 400 kPa. The hydraulic conductivity of the grouted sand decreased with increasing silica concentration in a nearly log-linear manner down to a minimum of 2 × 10−9 cm/s, and was below 1 × 10−7cm/s for grouts with 7.4% silica or more. Inclusion of 5% volumetric saturation of organics (tetrachloroethene, CCl4, or aniline) in the samples had little effect on the strength or hydraulic conductivity. Samples were immersed in test liquids (organics, HCl diluted to pH 3, distilled water saturated with organics, and distilled water control) for up to 1 year. All samples increased in strength except for those immersed in aniline; samples immersed in water saturated with aniline were also weaker than control samples.

97/04642 Effect of content and particle size distribution of high-calcium fly ash on the rheological properties of cement pastes: Grzeszczyk, S. and Lipowski, G. Cem. Concr. Res., 1997, 27, (6), 907–916

This paper prepared a novel double liquid grouting material (ultra-fine sulfoaluminate cement-based grouting material). Slurry A was composed of ultra-fine sulfoaluminate clinker, and slurry B was made from ultra-fine anhydrite and ultra-fine quicklime in accordance with a certain proportion. The properties and hydration process of the double liquid grouting material were studied in the process of adding quicklime from 0 wt.% to 30 wt.%, and the double liquid grouting material was studied with micro-calorimeter, thermal-thermogravimetric (DTA-TG) analysis, scanning electron microscopy and energy spectrum technique (SEM-DES), marsh cone flow time, setting time, compressive strength and expansion/shrinkage tests. The results showed that the double liquid slurry had a short setting time when quicklime was added, causing the rapid development of mechanical strength. The more the quicklime content, the longer the flow time of slurry B. The early expansion ratio increased gradually with the increase of the quicklime content. The DTA-TG and SEM-DES test results indicated that the ettringite and aluminum hydroxide are the main hydration products. And the research also found that the mechanical strength of the double liquid grouting material not only depended on the ettringite concentration, but the aluminum hydroxide content was another important influence factor.

Modern grouts and their uses : Dodd, M Tunn Tunnlg, V14, N10, Nov 1982, P20–21

The article discusses the uses of liquid grout materials in tunnelling applications. The grout is forced into soil or rock cavities and sets to render the treated ground impervious and increase its strength prior to excavation. The main differences between the types of grout are detailed under the following sections - particulate grouts and solution grouts. Particulate grouts cover cements and clays--the former bind soil with a cementitious mass forming a strong cohesive mass, while clay grouts do not impart strength but depend for their action on the formation of weak gels with a thixotropic action. Solution grouts depend on the reaction of two or more chemicals in solution to form a gel and are able to penetrate into soils of low permeability. This class of grout is described as being divided into two further classes - colloidal, silicate-based materials and organic polymerising solutions. The first are used for the same economic reasons as particulate grouts while the second, known as resin grouts, have found application in situations where there are permeability problems. The range of resin grouts available are detailed and also their use in particular cases. (TRRL)