The plasticity and low flowability of spoil discharge from clay soil often result in the clogging... more The plasticity and low flowability of spoil discharge from clay soil often result in the clogging of boreholes during jet grouting, thereby causing harmful ground displacement, which damages the normal function and safety of nearby underground infrastructures, pipelines, or overlying structures. This study proposed some control measures for jet grouting in clayey soil which combined with: (a) expanding the cross-section of the spoil exit (or borehole), (b) pre-cutting the surrounding soil with a water jet synchronized with jet grouting, and (c) placing additional guided holes for spoil discharge into the ground surface smoothly. The in-situ grouting test demonstrated that combining the abovementioned measures with the typical jet grouting process could mitigate the borehole clogging issue and minimizes excessive lateral displacement induced by jet grouting in clay layers. More importantly, a series of inspections, measurements, and monitoring results indicated that the proposed measures provide no adverse effects on the effective diameter, strength, and waterproofing of the jet-grouted columns. While the incorporation of the proposed measures into standard jet grouting procedures may result in additional time and construction expenses, it is recommended to implement them in areas where there is a high risk of borehole clogging.
This paper presents the use of a large diameter jet grouting technique for installation of jet gr... more This paper presents the use of a large diameter jet grouting technique for installation of jet grout piles for the MRTA Blue Line Extension Project in Bangkok, Thailand. The jet grouted piles were used to seal off the base of excavation at the TBM retrieval shaft from the high-water pressure. The procedure and design parameters of the large diameter jet grouting technique are provided in the paper. The required design parameters for the grouted materials were verified by conducting laboratory testing of coring samples obtained at the site. Moreover, the required design parameters were further verified by conducting a pumping test at the site. The results of the laboratory and field tests indicate that the design requirements of the treated materials can be met effectively using the large diameter jet grouting technique in Bangkok. Furthermore, the construction time and the associated cost were optimized using the large diameter jet grouting technique.
Evaluating the actual diameter of jet grouted columns plays a significant role in determining the... more Evaluating the actual diameter of jet grouted columns plays a significant role in determining the success of the jet grouting technology. An acoustic monitoring system capable of directly recording the sounds due to the erosion of soil from the jet grouting, detected at different distances from the jet nozzle was used to determine the diameters of the jet grouted columns. Although this acoustic monitoring system has been utilized by a number of researches in the world, further jet grouting acoustic data from various sites and soils are required to establish an acoustic database for future jet grouting work to estimate the effective diameters of jet grouted columns formed in the particular site. However, this system was first introduced in Thailand on Bangkok soils. Therefore, this study was conducted for the MRTA Orange Line Project in Bangkok, Thailand, to determine the effectiveness of this system on the Bangkok soils. The average threshold peak amplitudes and the standard deviations calculated from the acoustic data of trial test columns were used to define the effective diameters of jet grouted columns formed in the Bangkok soils for the future jet grouting practices. It was concluded that the acoustic monitoring system could be effectively used to assist in the large diameter jet grouting technique for the Bangkok soils.
Proceeding of the 21st SEAGS and 4th AGSSEA Conference, 2023
The V-Jet method is a high-pressure jet mixing technique that involves using the powerful energy ... more The V-Jet method is a high-pressure jet mixing technique that involves using the powerful energy of high-pressured grout injection with compressed air erodes ground and mixed grout with the soil to install a large diameter soil-cement column. According to the research, the use of jet grout technology, such as the V-Jet method, results in the production of waste spoil, which is a combination of eroded soil and grout, throughout the installation process. This is contrary to chemical grout technology in which injected grout is permeated in the ground. Therefore, the control of spoil recovery is essential for properly installing the V-Jet and minimizing ground displacement during the installation. Generally, spoil recovery in clayey soil is more complex than in sandy soil because of the thicker property of spoil in clayey soil. The conventional technique for improving spoil recovery in clayey soil, like pre-cutting by high-pressured water or additional water to the spoil pit, worsens construction productivity. This paper introduced an advanced agent for reducing viscosity effectively in clayey soils. Both laboratory and field tests were conducted to evaluate flow values and strength of jet grouted samples with the viscosity-reducing agent. It was concluded that using an appropriate amount of the viscosity-reducing agent resulted in good flowability during the jet-grouting process.
Proceeding of the 21st SEAGS and 4th AGSSEA Conference, 2023
The development of the jet grouting method has been a significant breakthrough in the field of ge... more The development of the jet grouting method has been a significant breakthrough in the field of geotechnical engineering. This construction method was initially developed in Japan in the 1960s and has undergone various improvements to enhance its effectiveness and efficiency. The jet grouting method involves the injection of a cement-based grout material into the ground through a high-pressure jet. It has many excellent features, such as a wide range of applicable soils, high improvement strength, and the ability to construct using small-diameter boreholes. This technique enables the creation of a solid column of grout material that can provide support to unstable soil or rock formations. However, the quality of the improved ground is influenced by various factors, including the quality of the injection flow, the lifting speed, the rotation frequency, and the soil conditions. Over the years, there have been efforts to develop new construction methods that can improve the performance of the jet grouting method. These efforts have led to the development of advanced equipment and techniques that can achieve higher grouting pressures and faster injection rates, resulting in a more efficient and cost-effective construction process. In this paper, the history of the development of the jet grouting method will be reviewed, and the basic improvement mechanism of the method the authors have worked on will be discussed. Furthermore, the development of new methods and future challenges and prospects for the jet grouting method will be discussed.
Smart Geotechnics for Smart Societies Edition: 1st Edition, 2023
The undrained shear strength is a critical design parameter in the design of soilcement columns f... more The undrained shear strength is a critical design parameter in the design of soilcement columns for ground improvement projects. This paper presents an evaluation of undrained shear strength in soil-cement columns constructed with the dry mixing method for Bangkok soft clay. The relationships between undrained shear strength and design parameters including cement content, total water-cement ratio, curing time, and natural moisture content were established using machine learning (ML) techniques in this study. Soil samples of soilcement column (SCC) were obtained from two sites including the AIT site and Highway No. 35 site. Different varieties of cement contents were mixed using the dry method to prepare laboratory SCC samples with curing times of 7, 14, and 28 days. The SCC samples were utilized to develop models including the multivariate regression (MLR) model, random forest (RF) model, and artificial neural network (ANN) regression model for prediction of the undrained shear strength. The coefficient of determination (R 2), mean absolute error (MAE), and root mean square error (RMSE) were used as performance detectors for different models. It was found that R 2 values for all models ranged from 0.70 to 0.99 for the training data and from 0.5 to 0.94 for the testing data. A linear equation using the MLR model to predict undrained shear strength was proposed using cement content, natural moisture content, and curing time as the primary parameters. Various graphs to predict undrained shear strength were also proposed using the RF and ANN models.
Smart Geotechnics for Smart Societies Edition: 1st Edition, 2023
In Bangkok, Thailand, the soils consist of a layer of soft clay underlain by interlayers of stiff... more In Bangkok, Thailand, the soils consist of a layer of soft clay underlain by interlayers of stiff clay and sand. The groundwater level is often observed a few meters below the ground surface. Unexpected incidents, such as water inflow from the sand aquifers and excessive deformation from the soft clay, could occur during TBM breakthroughs in such soil conditions. The jet grouting technique is commonly utilized for ground improvement to avoid these issues. This paper focuses on an evaluation of jet grouting design and construction methods related to water leakage issues for TBM breakthroughs. The design and construction data collected from the MRTA Orange Line East Project in Bangkok, Thailand, were used to evaluate key jet grouting design and construction parameters for TBM launching and arrival. A large-diameter jet grouting technique was used to form jet grouted blocks at the TBM launching and arrival areas. Regarding the design method, it was found that the cohesion of the jet grouting mixture is one of the key parameters that affect the jet grouted block dimension. The permeability and dimension of the jet grouted block are also essential design parameters when the tunnel is subjected to high water pressure at a greater depth. Regarding the construction method, it was concluded that to minimize construction issues a combination of many construction techniques, such as jet grouting, sealing rings, concrete blocks and flood of the chamber, should be applied to provide safer TBM breakthroughs.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
11th International Symposium Imperial Colleage UK, 2022
The constructions of high canal embankments on soft clays are faced with an enormous challenge in... more The constructions of high canal embankments on soft clays are faced with an enormous challenge in slope stability due to the instability of soft clay foundation and excessive lateral movement of soil if supported only by deep cement mixing (DCM) piles. A canal embankment supported by concrete piles with slab and DCM piles along the slope is currently being constructed on Bangkok soft clay in Bangkok, Thailand. In this paper, a numerical parametric study was performed using a finite element program to determine key design features that could affect the stability and lateral movement of the embankment. Differential settlement of the embankment in long-term conditions was also analyzed. The soil parameters used in the numerical analysis were back-calibrated using field measurement data obtained from a prior DCM pile project constructed on similar Bangkok soft clay in Bangkok, Thailand. It was concluded that the following four parametric characteristics including (1) the feasibility of concrete piles with slabs instead of the sole use of DCM piles, (2) the water level in the newly excavated canal, (3) the pattern of DCM piles, and (4) the length of the piles are considered as the critical design features that could significantly affect the stability and lateral movement of the embankment.
International Conference on Deep Foundations and Ground Improvment, 2022
The unconfined compressive strength (qu) is a critical design parameter in the design of jet-grou... more The unconfined compressive strength (qu) is a critical design parameter in the design of jet-grouted piles for ground improvement projects. This paper presents an evaluation of index properties affecting the unconfined compressive strength of jet-grouted samples for the Bangkok soils in Thailand. A database containing results of field investigation and laboratory testing for jet-grouted samples was created for this evaluation. The jet grouted samples were collected using a large diameter jet grouting technique from the MRTA Blue Line and Orange Line Projects in Bangkok, Thailand. This study focuses on two parts of analysis: (1) prediction of qu for the jet grouted samples using index properties of the soils obtained from the database, and (2) correlation between qu and Modulus of Elasticity (E50) of the jet grouted samples. The prediction of qu for the jet grouted samples using index properties of the soils was conducted using the Artificial Neural Network (ANN) model, which is a well-known data mining algorithm. Various index properties of the soil samples were selected in the ANN model to determine the most critical parameters in the prediction of qu. It was concluded that unit weight, grading curve, and plasticity index could be used to reasonably predict the qu using the ANN model. A correlation of E50 = 100×qu adopted by the Japan Jet Grout Association is commonly utilized in Southeast Asia for the design of jet-grouting projects. This correlation could largely depend on soil types and properties, jet-grouting techniques, and construction procedures. A correlation of E50 = 50×qu was found in this study for the jet-grouted soil samples collected in the database. It is recommended that this correlation be used for future jet-grouted projects in Thailand.
This paper presents the use of a large-diameter jet grouting technique for the installation of je... more This paper presents the use of a large-diameter jet grouting technique for the installation of jet grout piles for 2 different tunnel projects in Bangkok. The first project which the large diameter jet grouting technique was used is the MRTA Blue Line Extension Project in Bangkok, Thailand. The jet grouted piles were used to seal off the base of an excavation at the TBM retrieval shaft from the high-water pressure. The second project which the large diameter jet grouting technique was used is the MRTA Orange Line-East Project in Bangkok, Thailand. Preceding beams with a thickness of 3.0 m were designed and constructed to reduce the overstress that could induce to the pile foundation for the adjacent Srirat Expressway. The construction procedure and design parameters of the large-diameter jet grouting technique are provided in this paper. The required design parameters for the grouted materials were verified by conducting laboratory testing of core samples obtained at the site. Moreover, the required design parameters were further verified by conducting a pumping test and an electrical resistivity test at the site. The results of the laboratory and field tests indicate that the design requirements of the treated materials can be met effectively by using the large-diameter jet grouting technique in Bangkok. Furthermore, the construction time and the associated cost were found to be greatly reduced.
Geotechnical Engineering Journal of the SEAGS&AGSSEA, 2024
The development of the jet grouting method has been a significant breakthrough in the field of ge... more The development of the jet grouting method has been a significant breakthrough in the field of geotechnical engineering. This construction method was initially developed in Japan in the 1960s and has undergone various improvements to enhance its effectiveness and efficiency. The jet grouting method involves the injection of a cement-based grout material into the ground through a high-pressure jet. It has many excellent features, such as a wide range of applicable soils, high improvement strength, and the ability to construct using small-diameter boreholes. This technique enables the creation of a solid column of grout material that can provide support to unstable soil or rock formations. However, the quality of the improved ground is influenced by various factors, including the quality of the injection flow, the lifting speed, the rotation frequency, and the soil conditions. Over the years, there have been efforts to develop new construction methods that can improve the performance of the jet grouting method. These efforts have led to the development of advanced equipment and techniques that can achieve higher grouting pressures and faster injection rates, resulting in a more efficient and cost-effective construction process. In this paper, the history of the development of the jet grouting method will be reviewed, and the basic improvement mechanism of the method and case studies that the authors have worked on will be discussed. Furthermore, the development of new methods and future challenges and prospects for the jet grouting method will be discussed.
The construction of deep excavation involves potential uplift forces and water leakage due to hig... more The construction of deep excavation involves potential uplift forces and water leakage due to high water pressure. The Tube-a-Manchette (TAM) grouting technique was implemented in a 35-meter deep excavation retained by a 58-meter deep diaphragm wall to alleviate these issues. The grouting zone was located in a silty sand layer, and cement-bentonite (CB) grout and sodium silicate (MK) grout were used in the first and second stages, respectively. Volume control grouting was performed on site, with injection port pressures recorded. The pressure distribution plot and field pumping test were conducted to evaluate the grouting quality. The uplift stability analysis was conducted using the weight balance equation. Results showed improved stability of the bottom shaft after grouting work was completed, with a factor of safety ranging from 1.07 to 1.12 after excavation. The injection pressure of each port was within the design range (< 25 Bars), showing a very good uniformity distribution of the grouting application. The permeability of the improved soil was reduced by about 10 times compared to that of the original soil. Additionally, a comparison between the MWA project and similar projects in Thailand and Taiwan demonstrated the positive outcomes of the grouting work in this project for other silty sand sites with similar grouting parameters. These findings suggest that the TAM grouting method is effective in controlling uplift forces and water leakage in deep shaft constructions for water tunnels and can be used in other similar projects.
Good overlapping among jet grout columns is crucial for the success of waterproofing in the groun... more Good overlapping among jet grout columns is crucial for the success of waterproofing in the ground. Drilling alignment, column spacing, and diameter of jet grout columns are the controlling factors of good column overlapping. This study evaluated the drilling alignment of vertical and inclined jet grout columns using field-measured alignment data and statistical analysis. A three-dimensional (3-D) image of a jet-grouted mass was established by combining the measurement results of drilling alignment and jet grout column diameter from the trial test. The 3-D image was used to examine the overlapping of the jet grout columns and identify possible locations of windows (non-grouted zones) in the jet-grouted mass. Vertically drilled jet grout holes maintained excellent alignment, with an average estimated inclination angle of 0.43° and standard deviations of 0.11°. However, to avoid underground obstacles, inclined drilling is often required. An inclined drill jet grout hole can easily deviate from its designed drilling alignment because of gravity and result in poor overlapping and potential windows. The average estimated inclination angle and standard deviation of inclined drilling were approximately three times those of vertical drilling.
Proceedings of the Institution of Civil Engineers, Aug 1, 2015
This paper provides a summary report on measures taken to remove embedded steel ‘H' pile obst... more This paper provides a summary report on measures taken to remove embedded steel ‘H' pile obstacles from the cutter head of an advancing tunnel-boring machine. The piles were part of the soil-mixing retaining wall built for the cut-and-cover tunnel construction of a Taiwan high-speed rail tunnel and a Taiwan railways administration tunnel, which were directly above the mass rapid transit tunnel that was to be constructed. The collision zone between the boring machine and piles was below groundwater level and was approximately 23 m below the ground surface in a silty sand layer. To remove the piles safely from the cutter head, horizontal grouting from two adjacent work pits was conducted for waterproofing and solidification purposes. By controlling the amount of soil being flushed out during the grout hole drilling first, and also the pressure used for grouting later, the measured tunnel settlement resulting from grouting was negligible. Because of the favourable watertightness of the grouted zone and the d...
The plasticity and low flowability of spoil discharge from clay soil often result in the clogging... more The plasticity and low flowability of spoil discharge from clay soil often result in the clogging of boreholes during jet grouting, thereby causing harmful ground displacement, which damages the normal function and safety of nearby underground infrastructures, pipelines, or overlying structures. This study proposed some control measures for jet grouting in clayey soil which combined with: (a) expanding the cross-section of the spoil exit (or borehole), (b) pre-cutting the surrounding soil with a water jet synchronized with jet grouting, and (c) placing additional guided holes for spoil discharge into the ground surface smoothly. The in-situ grouting test demonstrated that combining the abovementioned measures with the typical jet grouting process could mitigate the borehole clogging issue and minimizes excessive lateral displacement induced by jet grouting in clay layers. More importantly, a series of inspections, measurements, and monitoring results indicated that the proposed measures provide no adverse effects on the effective diameter, strength, and waterproofing of the jet-grouted columns. While the incorporation of the proposed measures into standard jet grouting procedures may result in additional time and construction expenses, it is recommended to implement them in areas where there is a high risk of borehole clogging.
This paper presents the use of a large diameter jet grouting technique for installation of jet gr... more This paper presents the use of a large diameter jet grouting technique for installation of jet grout piles for the MRTA Blue Line Extension Project in Bangkok, Thailand. The jet grouted piles were used to seal off the base of excavation at the TBM retrieval shaft from the high-water pressure. The procedure and design parameters of the large diameter jet grouting technique are provided in the paper. The required design parameters for the grouted materials were verified by conducting laboratory testing of coring samples obtained at the site. Moreover, the required design parameters were further verified by conducting a pumping test at the site. The results of the laboratory and field tests indicate that the design requirements of the treated materials can be met effectively using the large diameter jet grouting technique in Bangkok. Furthermore, the construction time and the associated cost were optimized using the large diameter jet grouting technique.
Evaluating the actual diameter of jet grouted columns plays a significant role in determining the... more Evaluating the actual diameter of jet grouted columns plays a significant role in determining the success of the jet grouting technology. An acoustic monitoring system capable of directly recording the sounds due to the erosion of soil from the jet grouting, detected at different distances from the jet nozzle was used to determine the diameters of the jet grouted columns. Although this acoustic monitoring system has been utilized by a number of researches in the world, further jet grouting acoustic data from various sites and soils are required to establish an acoustic database for future jet grouting work to estimate the effective diameters of jet grouted columns formed in the particular site. However, this system was first introduced in Thailand on Bangkok soils. Therefore, this study was conducted for the MRTA Orange Line Project in Bangkok, Thailand, to determine the effectiveness of this system on the Bangkok soils. The average threshold peak amplitudes and the standard deviations calculated from the acoustic data of trial test columns were used to define the effective diameters of jet grouted columns formed in the Bangkok soils for the future jet grouting practices. It was concluded that the acoustic monitoring system could be effectively used to assist in the large diameter jet grouting technique for the Bangkok soils.
Proceeding of the 21st SEAGS and 4th AGSSEA Conference, 2023
The V-Jet method is a high-pressure jet mixing technique that involves using the powerful energy ... more The V-Jet method is a high-pressure jet mixing technique that involves using the powerful energy of high-pressured grout injection with compressed air erodes ground and mixed grout with the soil to install a large diameter soil-cement column. According to the research, the use of jet grout technology, such as the V-Jet method, results in the production of waste spoil, which is a combination of eroded soil and grout, throughout the installation process. This is contrary to chemical grout technology in which injected grout is permeated in the ground. Therefore, the control of spoil recovery is essential for properly installing the V-Jet and minimizing ground displacement during the installation. Generally, spoil recovery in clayey soil is more complex than in sandy soil because of the thicker property of spoil in clayey soil. The conventional technique for improving spoil recovery in clayey soil, like pre-cutting by high-pressured water or additional water to the spoil pit, worsens construction productivity. This paper introduced an advanced agent for reducing viscosity effectively in clayey soils. Both laboratory and field tests were conducted to evaluate flow values and strength of jet grouted samples with the viscosity-reducing agent. It was concluded that using an appropriate amount of the viscosity-reducing agent resulted in good flowability during the jet-grouting process.
Proceeding of the 21st SEAGS and 4th AGSSEA Conference, 2023
The development of the jet grouting method has been a significant breakthrough in the field of ge... more The development of the jet grouting method has been a significant breakthrough in the field of geotechnical engineering. This construction method was initially developed in Japan in the 1960s and has undergone various improvements to enhance its effectiveness and efficiency. The jet grouting method involves the injection of a cement-based grout material into the ground through a high-pressure jet. It has many excellent features, such as a wide range of applicable soils, high improvement strength, and the ability to construct using small-diameter boreholes. This technique enables the creation of a solid column of grout material that can provide support to unstable soil or rock formations. However, the quality of the improved ground is influenced by various factors, including the quality of the injection flow, the lifting speed, the rotation frequency, and the soil conditions. Over the years, there have been efforts to develop new construction methods that can improve the performance of the jet grouting method. These efforts have led to the development of advanced equipment and techniques that can achieve higher grouting pressures and faster injection rates, resulting in a more efficient and cost-effective construction process. In this paper, the history of the development of the jet grouting method will be reviewed, and the basic improvement mechanism of the method the authors have worked on will be discussed. Furthermore, the development of new methods and future challenges and prospects for the jet grouting method will be discussed.
Smart Geotechnics for Smart Societies Edition: 1st Edition, 2023
The undrained shear strength is a critical design parameter in the design of soilcement columns f... more The undrained shear strength is a critical design parameter in the design of soilcement columns for ground improvement projects. This paper presents an evaluation of undrained shear strength in soil-cement columns constructed with the dry mixing method for Bangkok soft clay. The relationships between undrained shear strength and design parameters including cement content, total water-cement ratio, curing time, and natural moisture content were established using machine learning (ML) techniques in this study. Soil samples of soilcement column (SCC) were obtained from two sites including the AIT site and Highway No. 35 site. Different varieties of cement contents were mixed using the dry method to prepare laboratory SCC samples with curing times of 7, 14, and 28 days. The SCC samples were utilized to develop models including the multivariate regression (MLR) model, random forest (RF) model, and artificial neural network (ANN) regression model for prediction of the undrained shear strength. The coefficient of determination (R 2), mean absolute error (MAE), and root mean square error (RMSE) were used as performance detectors for different models. It was found that R 2 values for all models ranged from 0.70 to 0.99 for the training data and from 0.5 to 0.94 for the testing data. A linear equation using the MLR model to predict undrained shear strength was proposed using cement content, natural moisture content, and curing time as the primary parameters. Various graphs to predict undrained shear strength were also proposed using the RF and ANN models.
Smart Geotechnics for Smart Societies Edition: 1st Edition, 2023
In Bangkok, Thailand, the soils consist of a layer of soft clay underlain by interlayers of stiff... more In Bangkok, Thailand, the soils consist of a layer of soft clay underlain by interlayers of stiff clay and sand. The groundwater level is often observed a few meters below the ground surface. Unexpected incidents, such as water inflow from the sand aquifers and excessive deformation from the soft clay, could occur during TBM breakthroughs in such soil conditions. The jet grouting technique is commonly utilized for ground improvement to avoid these issues. This paper focuses on an evaluation of jet grouting design and construction methods related to water leakage issues for TBM breakthroughs. The design and construction data collected from the MRTA Orange Line East Project in Bangkok, Thailand, were used to evaluate key jet grouting design and construction parameters for TBM launching and arrival. A large-diameter jet grouting technique was used to form jet grouted blocks at the TBM launching and arrival areas. Regarding the design method, it was found that the cohesion of the jet grouting mixture is one of the key parameters that affect the jet grouted block dimension. The permeability and dimension of the jet grouted block are also essential design parameters when the tunnel is subjected to high water pressure at a greater depth. Regarding the construction method, it was concluded that to minimize construction issues a combination of many construction techniques, such as jet grouting, sealing rings, concrete blocks and flood of the chamber, should be applied to provide safer TBM breakthroughs.
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
11th International Symposium Imperial Colleage UK, 2022
The constructions of high canal embankments on soft clays are faced with an enormous challenge in... more The constructions of high canal embankments on soft clays are faced with an enormous challenge in slope stability due to the instability of soft clay foundation and excessive lateral movement of soil if supported only by deep cement mixing (DCM) piles. A canal embankment supported by concrete piles with slab and DCM piles along the slope is currently being constructed on Bangkok soft clay in Bangkok, Thailand. In this paper, a numerical parametric study was performed using a finite element program to determine key design features that could affect the stability and lateral movement of the embankment. Differential settlement of the embankment in long-term conditions was also analyzed. The soil parameters used in the numerical analysis were back-calibrated using field measurement data obtained from a prior DCM pile project constructed on similar Bangkok soft clay in Bangkok, Thailand. It was concluded that the following four parametric characteristics including (1) the feasibility of concrete piles with slabs instead of the sole use of DCM piles, (2) the water level in the newly excavated canal, (3) the pattern of DCM piles, and (4) the length of the piles are considered as the critical design features that could significantly affect the stability and lateral movement of the embankment.
International Conference on Deep Foundations and Ground Improvment, 2022
The unconfined compressive strength (qu) is a critical design parameter in the design of jet-grou... more The unconfined compressive strength (qu) is a critical design parameter in the design of jet-grouted piles for ground improvement projects. This paper presents an evaluation of index properties affecting the unconfined compressive strength of jet-grouted samples for the Bangkok soils in Thailand. A database containing results of field investigation and laboratory testing for jet-grouted samples was created for this evaluation. The jet grouted samples were collected using a large diameter jet grouting technique from the MRTA Blue Line and Orange Line Projects in Bangkok, Thailand. This study focuses on two parts of analysis: (1) prediction of qu for the jet grouted samples using index properties of the soils obtained from the database, and (2) correlation between qu and Modulus of Elasticity (E50) of the jet grouted samples. The prediction of qu for the jet grouted samples using index properties of the soils was conducted using the Artificial Neural Network (ANN) model, which is a well-known data mining algorithm. Various index properties of the soil samples were selected in the ANN model to determine the most critical parameters in the prediction of qu. It was concluded that unit weight, grading curve, and plasticity index could be used to reasonably predict the qu using the ANN model. A correlation of E50 = 100×qu adopted by the Japan Jet Grout Association is commonly utilized in Southeast Asia for the design of jet-grouting projects. This correlation could largely depend on soil types and properties, jet-grouting techniques, and construction procedures. A correlation of E50 = 50×qu was found in this study for the jet-grouted soil samples collected in the database. It is recommended that this correlation be used for future jet-grouted projects in Thailand.
This paper presents the use of a large-diameter jet grouting technique for the installation of je... more This paper presents the use of a large-diameter jet grouting technique for the installation of jet grout piles for 2 different tunnel projects in Bangkok. The first project which the large diameter jet grouting technique was used is the MRTA Blue Line Extension Project in Bangkok, Thailand. The jet grouted piles were used to seal off the base of an excavation at the TBM retrieval shaft from the high-water pressure. The second project which the large diameter jet grouting technique was used is the MRTA Orange Line-East Project in Bangkok, Thailand. Preceding beams with a thickness of 3.0 m were designed and constructed to reduce the overstress that could induce to the pile foundation for the adjacent Srirat Expressway. The construction procedure and design parameters of the large-diameter jet grouting technique are provided in this paper. The required design parameters for the grouted materials were verified by conducting laboratory testing of core samples obtained at the site. Moreover, the required design parameters were further verified by conducting a pumping test and an electrical resistivity test at the site. The results of the laboratory and field tests indicate that the design requirements of the treated materials can be met effectively by using the large-diameter jet grouting technique in Bangkok. Furthermore, the construction time and the associated cost were found to be greatly reduced.
Geotechnical Engineering Journal of the SEAGS&AGSSEA, 2024
The development of the jet grouting method has been a significant breakthrough in the field of ge... more The development of the jet grouting method has been a significant breakthrough in the field of geotechnical engineering. This construction method was initially developed in Japan in the 1960s and has undergone various improvements to enhance its effectiveness and efficiency. The jet grouting method involves the injection of a cement-based grout material into the ground through a high-pressure jet. It has many excellent features, such as a wide range of applicable soils, high improvement strength, and the ability to construct using small-diameter boreholes. This technique enables the creation of a solid column of grout material that can provide support to unstable soil or rock formations. However, the quality of the improved ground is influenced by various factors, including the quality of the injection flow, the lifting speed, the rotation frequency, and the soil conditions. Over the years, there have been efforts to develop new construction methods that can improve the performance of the jet grouting method. These efforts have led to the development of advanced equipment and techniques that can achieve higher grouting pressures and faster injection rates, resulting in a more efficient and cost-effective construction process. In this paper, the history of the development of the jet grouting method will be reviewed, and the basic improvement mechanism of the method and case studies that the authors have worked on will be discussed. Furthermore, the development of new methods and future challenges and prospects for the jet grouting method will be discussed.
The construction of deep excavation involves potential uplift forces and water leakage due to hig... more The construction of deep excavation involves potential uplift forces and water leakage due to high water pressure. The Tube-a-Manchette (TAM) grouting technique was implemented in a 35-meter deep excavation retained by a 58-meter deep diaphragm wall to alleviate these issues. The grouting zone was located in a silty sand layer, and cement-bentonite (CB) grout and sodium silicate (MK) grout were used in the first and second stages, respectively. Volume control grouting was performed on site, with injection port pressures recorded. The pressure distribution plot and field pumping test were conducted to evaluate the grouting quality. The uplift stability analysis was conducted using the weight balance equation. Results showed improved stability of the bottom shaft after grouting work was completed, with a factor of safety ranging from 1.07 to 1.12 after excavation. The injection pressure of each port was within the design range (< 25 Bars), showing a very good uniformity distribution of the grouting application. The permeability of the improved soil was reduced by about 10 times compared to that of the original soil. Additionally, a comparison between the MWA project and similar projects in Thailand and Taiwan demonstrated the positive outcomes of the grouting work in this project for other silty sand sites with similar grouting parameters. These findings suggest that the TAM grouting method is effective in controlling uplift forces and water leakage in deep shaft constructions for water tunnels and can be used in other similar projects.
Good overlapping among jet grout columns is crucial for the success of waterproofing in the groun... more Good overlapping among jet grout columns is crucial for the success of waterproofing in the ground. Drilling alignment, column spacing, and diameter of jet grout columns are the controlling factors of good column overlapping. This study evaluated the drilling alignment of vertical and inclined jet grout columns using field-measured alignment data and statistical analysis. A three-dimensional (3-D) image of a jet-grouted mass was established by combining the measurement results of drilling alignment and jet grout column diameter from the trial test. The 3-D image was used to examine the overlapping of the jet grout columns and identify possible locations of windows (non-grouted zones) in the jet-grouted mass. Vertically drilled jet grout holes maintained excellent alignment, with an average estimated inclination angle of 0.43° and standard deviations of 0.11°. However, to avoid underground obstacles, inclined drilling is often required. An inclined drill jet grout hole can easily deviate from its designed drilling alignment because of gravity and result in poor overlapping and potential windows. The average estimated inclination angle and standard deviation of inclined drilling were approximately three times those of vertical drilling.
Proceedings of the Institution of Civil Engineers, Aug 1, 2015
This paper provides a summary report on measures taken to remove embedded steel ‘H' pile obst... more This paper provides a summary report on measures taken to remove embedded steel ‘H' pile obstacles from the cutter head of an advancing tunnel-boring machine. The piles were part of the soil-mixing retaining wall built for the cut-and-cover tunnel construction of a Taiwan high-speed rail tunnel and a Taiwan railways administration tunnel, which were directly above the mass rapid transit tunnel that was to be constructed. The collision zone between the boring machine and piles was below groundwater level and was approximately 23 m below the ground surface in a silty sand layer. To remove the piles safely from the cutter head, horizontal grouting from two adjacent work pits was conducted for waterproofing and solidification purposes. By controlling the amount of soil being flushed out during the grout hole drilling first, and also the pressure used for grouting later, the measured tunnel settlement resulting from grouting was negligible. Because of the favourable watertightness of the grouted zone and the d...
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Papers by Ricky Wong