Shinya Inazumi

• Professor PhD
• Professor at Shibaura Institute of Technology

This study investigates the sustainable use of seabed dredged sediments and water treatment sludges as construction materials using combined dewatering and cement stabilization techniques. Dredged sediments and water treatment sludges, typically considered waste, were evaluated for their suitability in construction through a series of dewatering an...

This paper presents a thorough guide to simulating jet grouting using the Moving Particle Semi-Implicit (MPS) method for numerical analysis and Computer-Aided Engineering (CAE) for model development. It addresses the shortcomings of previous jet grouting simulation studies, which often lacked clear and comprehensive guidelines, by providing a detai...

This study investigates the sustainable use of seabed dredged slud‬ge and water treatment sludges as construction materials using combined dewatering and cement stabilization techniques. Dredged sediments and water treatment sludges, typically considered waste, were evaluated for their suitability in construction through a series of dewatering and...

This paper presents a thorough guide to simulating jet grouting using the Moving Particle Semi-Implicit (MPS) method for numerical analysis and Computer-Aided Engineering (CAE) for model development. It addresses the shortcomings of previous jet grouting simulation studies, which often lacked clear and comprehensive guidelines, by providing a detai...

This study introduces Soil Squeezing Technology (SST) as an innovative approach to soil improvement that addresses the limitations of conventional methods in urban geotechnical projects. Unlike traditional in-situ mixing, SST uses displacement, compaction, and controlled solidification to effectively increase soil cohesion and strength while reduci...

This review examines the integration of ground source heat pump (GSHP) systems with energy piles as a sustainable approach to improving energy efficiency in smart cities. Energy piles, which combine structural support with geothermal heat exchange, offer significant advantages over conventional air source heat pumps (ASHPs) by using stable ground t...

There is no unified view on the strength development mechanism of chemically grouted sand, which has not been clarified yet. This study investigated the cohesion and friction angle, which are the shearing strength components of the chemical grouted sand, using a consolidated drained triaxial compression test. The microscopic molecular structure of...

This paper examines how smart cities can address land subsidence and liquefaction in the context of rapid urbanization in Japan. Since the 1960s, liquefaction has been an important topic in geotechnical engineering, and extensive efforts have been made to evaluate soil resistance to liquefaction. Currently, there is a lack of machine learning appli...

Urban areas are increasingly challenged by the urban heat island effect, resulting in increased energy consumption and reduced efficiency of conventional air source heat pumps (ASHPs). This study explores the integration of ground source heat pump (GSHP) systems with energy piles in urban environments, focusing on small to medium sized residential...

This paper explores how smart cities can cope with land subsidence and liquefaction in the context of rapid urbanization in Japan. Since the 1960s, liquefaction has become an important topic in geotechnical engineering, and great efforts have been made to evaluate the resistance of soil to liquefaction. There is currently a lack of machine learning...

In response to increasing urbanization and the need for infrastructure resilient to natural hazards, this study introduces an AI-driven predictive model designed to assess the risk of soil liquefaction. Utilizing advanced ensemble machine learning techniques, the model integrates geotechnical and geographical data to accurately predict the potentia...

In response to increasing urbanization and the need for infrastructure resilient to natural hazards, this study introduces an AI-driven predictive model designed to assess the risk of soil liquefaction. Utilizing advanced ensemble machine learning techniques, the model integrates geotechnical and geographical data to accurately predict the potentia...

This study examines the optimization of ground source heat pump (GSHP) systems and energy piles for sustainable urban development, focusing on Southeast Asia. GSHPs, which utilize geothermal energy for indoor HVAC needs, offer a sustainable alternative to traditional systems by utilizing consistent subsurface temperatures for heating and cooling. T...

This paper undertakes a comprehensive review to underscore the central role of sustainability in the evaluation and innovation of jet grouting technologies. It meticulously traces the evolution of evaluation methodologies, emphasizing the imperative of sustainable practices throughout history. Traditional evaluation paradigms are examined alongside...

This paper addresses challenges and solutions in urban development and infrastructure resilience, particularly in the context of Japan’s rapidly urbanizing landscape. It explores the integration of smart city concepts to combat land subsidence and liquefaction, phenomena highlighted by the 2011 Great East Japan Earthquake. Additionally, it examines...

This study examines the optimization of ground source heat pump (GSHP) systems and energy piles for sustainable urban development, with a focus on Southeast Asia. GSHPs, which utilize geothermal energy for indoor HVAC needs, offer a sustainable alternative to traditional systems by utilizing consistent subsurface temperatures for heating and coolin...

This paper undertakes a comprehensive review to underscore the central role of sustainability in the evaluation and innovation of jet grouting technologies. It meticulously traces the evolution of evaluation methodologies, emphasizing the imperative of sustainable practices throughout history. Traditional evaluation paradigms are examined alongside...

This paper aims to investigate the impact of low permeability layers in the ground on chemical infiltration by utilizing seepage flow analysis. Additionally, we present the outcomes of a multiple regression analysis conducted using the data obtained from the seepage flow analysis. The chemical injection method has experienced extensive usage in rec...

In this paper, we use AI to predict the ground information at unknown points from the ground information at known points in Urayasu City, which has a large amount of reclaimed land and a very high liquefaction potential. The paper also introduces a liquefaction hazard map and a method for indicating liquefaction hazard using the PL method based on...

The accuracy control during the construction in the soil improvement work was mainly the empirical control of the construction manager such as attitude of the construction machine and experience of the operator. There is a growing need for technology that able to measure and control the track at the tip of a mixing tool in real time and with high a...

This paper addresses challenges and solutions in urban development and infrastructure resilience, particularly in the context of Japan's rapidly urbanizing landscape. It explores the integration of smart city concepts to combat land subsidence and liquefaction, phenomena highlighted by the 2011 Great East Japan Earthquake. Using advanced technologi...

The objective of this study was to investigate the liquefaction resistance of chemically improved sandy soils in a straightforward and accurate manner. Using only the existing experimental databases and artificial intelligence, the goal was to predict the experimental results as supporting information before performing the physical experiments. Emp...

The objective of this study was to investigate the liquefaction resistance of chemically improved sandy soils in a straightforward and accurate manner. Using only the existing experimental databases and artificial intelligence, the goal was to make predictions without conducting physical experiments. Emphasis was placed on the significance of data...

This study emphasizes the importance of accurate input parameters for ensuring the precision and reliability of simulations by conducting a sensitivity analysis to determine the calculation and material parameters. The aim is to determine the exact material parameters, for two different soil samples in a rigid state, by comparing the results of a s...

The chemical injection method is one of the ground improvement methods used to stop water and increase strength. It is essential for soft ground improvement. Although the chemical injection method is a proven technique, it still faces technical challenges. The improved area and strength are generally non-uniform because the area to be improved cann...

For years, the chemical injection process has aided construction works by increasing the strength and water-sealing efficiency of sandy soil. Despite its growing popularity in projects, such as seismic strengthening and liquefaction mitigation, a unified understanding of how chemically treated soil develops its strength, especially under static con...

The demolition of an outdated infrastructure includes the removal of both the superstructure and the substructures. High-rise buildings have piles installed in them. Therefore, to reclaim the land for future use, it is necessary to remove the existing pile foundation and to backfill the boreholes remaining from the removal with suitable fillers so...

This paper focuses on the development of high-flowability liquefied stabilized soils (HFLSS) made of recycled construction sludge (RCS) to enhance their application in construction work. Liquefied stabilized soils (LSSs) have already found widespread use in construction sites, particularly for filling long-distance structures and dealing with compl...

The promotion of the SDGs (Sustainable Development Goals) for a sustainable and better society has been actively implemented in all sectors, including the construction industry. In contrast to other industries, however, the construction industry produces a great amount of waste while using a vast amount of resources. The effective utilization of re...

Groundwater level changes have numerous effects on buildings, such as differential ground deformation and cracking on the wall. In Bangkok, Thailand, change in groundwater levels changing was caused by groundwater pumping that took place from 1978 to 1997. This is the main effect of ground deformation in a wide area of the Bangkok plain. According...

The major focus of this study was determining the effectiveness of new construction specifications regarding the method of cement grout injection for the jet grouting system (high-pressure injection stirring method), with the objective of developing a sustainable ground improvement method. The recent innovative jet grouting techniques allow for imp...

In the field of geotechnical engineering, the problems of liquefaction and land subsidence are of major concern. In order to mitigate or prevent damage from liquefaction, the chemical injection method is actively used as one of the countermeasures for ground improvement. However, a complete understanding of the long-term sustainability of improved...

The infrastructures that were constructed decades ago do not meet the present structural benchmark, and they need to be demolished. In order to reclaim these lands, the existing pile foundations must be removed; otherwise, the land will lose its value. Since the piles are pulled out, vacant spaces are created in the ground. This causes the surround...

The progress status of jet-grouting construction during the construction phase is difficult to verify and even after the completion of construction, it can be verified only by empirical methods. This study attempted to recreate a realistic simulation result of the middle-pressure jet-grouting method by establishing a computer-aided engineering (CAE...

The groundwater level is a significant factor when assessing the sustainability of soil/ground environmental factors, such as bearing capacity behavior and soil surface displacement. Normally, groundwater level changes depend on deep-well pumping in industrial and economic development areas in many countries, especially Bangkok, Thailand. Groundwat...

The Chao Phraya River basin is located in the central area of Thailand, which experiences many land subsidence issues due to groundwater pumping. The Department of Groundwater Resources (DGR) has been recording data on the changes in the groundwater level due to water pumping since 1960 until the present time. In 1997, the DGR issued a law regulati...

In recent years, there has been an increasing demand to replace ancient structures. The removal of such structures also involves the removal of the existing piles that supported the structures, and the backfilling of the pulling-out holes that formed during the removal. However, there are no standard guidelines for the backfilling of pulling-out ho...

The mechanism of liquefaction and the factors that cause liquefaction behavior have previously been examined and evaluated, both analytically and experimentally; construction including liquefaction countermeasures is being implemented, based on these findings. This study presents a theoretical visualization of the mechanism of liquefaction generati...

Around the world, and especially in Japan, the tearing down of social infrastructure, including civil engineering structures, has been increasing due to the aging of these constructions, which were built during a period of high economic growth, and a decrease in their utilization caused by a recent drop in the population. The number of existing pil...

It has been reported that the strength decreases due to the waiting time until casting (Issue 1) and the strength homogeneity at the upper / middle / lower part due to material separation (Issue 2). For Issue 1, there is a possibility that the strength decrease due to the waiting time can be suppressed by improving the casting efficiency. For Issue...

It has been confirmed that manholes may protrude from the road surface due to the liquefaction of the ground during a large earthquake. When the uplifting of a manhole occurs, it may bring about not only dysfunctions, such as the loss of the ability of sewage to flow, but also displacements, such as that of the pipeline connected to the manhole, wh...

This study focused on the in-situ mixing process of middle-pressure jet grouting method of 20 MPa or less and aims to establish a computer-aided engineering (CAE) system that can simulate the performance on a computer from the planning/design stages. This ground improvement method is the combination of a jet grouting method and a jet grouting with...

In the conventional ground improvement method, the strength is exhibited by stirring and solidifying the solidifying material in the ground, so it is difficult to expect a strength higher than the solidifying potential of the solidifying material. In addition, because the soil is directly agitated with solidifying material in the in-situ, there is...

Most of the ground in Japan is soft, leading to great damage in the event of liquefaction. Various ground-improvement measures are being taken to suppress such damage. However, it is difficult to carry out ground-improvement work while checking the internal conditions of the ground during the construction. Therefore, a visible and measurable evalua...

The impacts of various hydrological processes such as infiltration, saturated/unsaturated seepage and river drawdown on bank retreat are complex, yet crucial in understanding fluvial erosion processes. The bank retreat generally occurs due to a combination of erosion and mass failure. In this study, coupled analyses of a bank retreat during prolong...

One of the common issues related to the ground improvement methods is that it is difficult to properly design and manage the construction process of improved soil body because the condition inside the target ground cannot be directly confirmed (visualized) during the construction. if the target ground can be modeled using a computer and the excavat...

As a solidifying material for ground improvement using inorganic waste as a raw material, the authors have been developing an additive mixture of the fine powder of waste glass containing a large amount of silica generated during the production of glass cullet and an alkaline aid (heat-treating type of “Earth-Silica; ES” additive). Furthermore, a s...

In recent years, the demand has been increasing for ground improvement work for seismic reinforcement and as a countermeasure to liquefaction utilizing Information Construction Technology, Internet of Things, and Building Information Modeling. Therefore, it is expected that more and more attention will be paid to construction management related to...

In this research, the authors are developing a solidifying material for ground improvement using inorganic waste as a raw material. The solidifying material is a mixture of blast furnace slag, inorganic waste containing a large amount of silica (such as waste glass fine powder or fly ash), and an alkaline aid while being heat-treated. In this paper...

This study focused on the middle-pressure jet grouting method, which has a complicated development mechanism for the columnar soil-improved body, with the aim of establishing a computer-aided engineering (CAE) system that can simulate the performance on a computer. Furthermore, in order to confirm the effect of middle-pressure jet grouting with mec...

One of the common issues related to ground-improvement methods is the difficulty of properly designing and managing the construction process of the improved soil body because the conditions inside the target ground cannot be directly confirmed (visualized) during the construction. If the target ground can be modeled using a computer, and the excava...

This study investigated the effects of relative humidity (Rh) or total suction condition during curing on small-strain shear modulus (G0) of a cement-treated silty sand using free-free resonant frequency tests (FFR). The moduli were determined on samples cured at different suctions corresponding to three Rh values of 7%, 75%, and 100%, in both unso...

Various issues have been encountered in the removal work of existing piles, such as existing piles being left in the ground, the subsidence of the surrounding ground and the deterioration of the ground environment when reusing the site. However, there are no regulations for the filling material to be injected into the draw holes that form after the...

In recent years, demolition of incompatible structures is increasing under those for the aging of a large number of social infrastructures constructed during the period of high economic growth, the decrease in the use of social infrastructures including residential housing and housing condominiums due to the population decline, and the disaster pre...

The teardowns of social infrastructures, including civil engineering structures, have been increasing due to the aging of these structures, which were built in a period of high economic growth, and to a decrease in their utilization due the recent drop in population. The number of existing pile foundations being pulled out has gradually become a lo...

In recent years, removal work of existing piles has been increasing, and many pulling-out methods for existing piles are being applied. As for the present situation, there is concern that the physical characteristics of the ground will deteriorate due to the holes that remain after pulling out the existing piles (pullout holes). In addition, the fi...

From the perspective of soil engineering, soil is uncertain and heterogeneous. Therefore, if an attempt is made to determine the soil classification of a soil without a precise test, for example, an engineer’s individual judgement is often involved in making the determination based on his/her own experiences. In relation to acquiring vast and varie...

From a geotechnical point of view, soil is uncertain and heterogeneous. Therefore, for example, if an attempt is made to determine the soil classification without a precise test, certain experiences may be required, and individual differences may appear in the determination. Against the background of inheriting these knowledges and being susceptibl...

Despite the occurrence of various problems, such as the remaining of existing piles due to existing pile extraction work, subsidence of the surrounding ground, and deterioration of the ground environment when using the former site, it is injected into the extraction holes formed after extraction of the existing piles. There is no provision in the f...

The pulling out of existing pile is one of the critical issues in recent years with the aging of infrastructures, and it is difficult to clarify that the construction has been completely carried out because it cannot be directly observed. In recent years, two types of a wire rope type and a chucking type have been generally applied for pulling out...

Ground-improvement technology, aimed at ensuring the stability of the ground, can achieve the desired ground strength and other geological conditions by artificially improving soft grounds. Although many ground-improvement technologies have been proposed, there are few ways to confirm whether the target ground improvement has actually been carried...

This paper clarifies the flow analysis method of fluidization-treated soils using 3D granules analysis by distinct element method (DEM) and the validity of the method. In recent years, fluidization-treated soils have been widely used as a material for landfilling such as underground space and so on in Japan. However, in the design and construction...

A series of studies aims to develop superabsorbent polymer-based soil conditioner as new soil conditioner in classification sorting treatment of higher water content soil and viscosity soil. In this study, the soil improvement effect by the soil improvement material based on super absorbent polymer, the property of the improved soil was verified. A...

Past research has developed a powdery silica-based admixture of inorganic waste containing a large amount of silica component such as a waste glass and a fly ash. It is effective as a solidifying material by mixing with a blast furnace slag. In addition, it can be expected to have superior characteristics as well as high strength as compared with c...

In ground-improvement work, it is important to make effective use of the various pieces of information obtained during construction and to ensure the shape and quality of the soil-improvement body. Therefore, in a series of studies, the authors have developed a system to visualize the ground by kinetically measuring it in real time in parallel with...

The purpose of this research is to reduce the amount of waste material in the form of blast furnace slag and discarded glass produced and effectively utilize it while preventing the exhaustion of natural resources and reducing the amount disposed of in final landfill sites. Therefore a powdered silica admixture made through heat treatment of inorga...

In past studies, a powdery silica-based admixture was developed. It was obtained by applying the heat treatment to inorganic waste, such as waste glass and fly ash containing a large amount of silica. The silica-based admixture has also been recognized as an effective solidifying material when it is mixed with blast furnace slag. The colloidal sili...

Certain issues may be encountered when traditional composite fillers are mixed with cement and bentonite (CF-CB) and applied to cavities in the ground. These issues include the bleeding and separating of water, cement and bentonite, and the long time needed for the strength development. In a series of studies, it has been shown that the suppression...

In a series of studies, it is aimed to develop fillings for holes formed by pulling-out piles. Cement-bentonite is used as a filling in general. Although cement-bentonite has an advantage of being able to perform blending according to circumstance of work on site, cement and water cause segregation, so uniform filling is difficult. In addition, the...

Impervious coating treatment is an original technology which consists of coating of soil and solid waste by particle units with an impervious coating material (a sealing material) containing water-absorbent polymers. The elution of attached substances, such as heavy metals, from the surface of soil particles is suppressed. This is because each part...

In general, the pulling-out method is adopted for removing existing piles, in particular the method to pulling-out the head of a pile with a wire rope is used. However, there is a possibility of leaving a part of the existing pile in the ground in the case of a damaged existing pile, and it is possible to induce inhomogeneous pulling-out hole with...

In Japan, even if it is seen worldwide, it has a lot of earthquakes, and it is said that Japan is an earth-quake nation. Therefore, we must think about earthquakes in situation of our lives. And the thing from which we will suffer great damage by a big earthquake the near future is expected, for example, Nankai Trough massive earthquake. However, i...

The mixing cement with soft soil to increase their strength has been used in many construction sites and it is important that soil and cement are well mixed. In order to evaluate the mixing accuracy during construction, it may be required to measure the cement content by sampling the cement mixed soil. While there are several methods for measuring...

The chemical grouting is one type of ground-improvement methods. It injects liquid consolidation material into the gaps of a soft sandy ground. It is mainly used for improving a stable ground, such as by preventing liquefaction and increasing the strength of the ground. Chemical grouting has been successfully applied at many construction sites; how...

Many tide breakwaters had been damaged by the impact of a tsunami that occurred due to the Great Tohoku Earthquake in 2011. As a restoration works, a tide breakwater with the length of about 800m and the height of T.P. +14.5m is being constructed in the coast of Katagishi in Iwate prefecture. In which, a special deep-mixing method with large diamet...

In late years, quantity of construction by-products tends to increase in our country. Therefore, dumping restraint of construction by-products and promote those recycling are the most critical issue from a viewpoint of establishing the recycling society. In the other hand, soils generated from construction generally show strong alkalinity because c...