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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 detailed step-by-step approach. The key aspects of the simulation that define and shape the output of real-world jet grouting technology, such as jet grouting spray settings and material parameter configurations, are validated against benchmark experimental data. The previously challenging task of accurately determining material parameters for soil when modeled as a Bingham fluid bi-viscosity model, is simplified into a universal guideline that can be easily applied to any soil type with known unconfined compressive strength. Finally, the reliability of the jet grouting simulation is confirmed by comparing the simulation results with benchmark experimental data under similar conditions, demonstrating the robustness and accuracy of the proposed method. [ABSTRACT FROM AUTHOR]

Jet grouting is a geotechnical consolidation technique commonly used to improve soil mechanicals. Despite its successful applications, understanding micro-level interactions between the jet and soil is incomplete. This paper utilizes the Smoothed Particle Hydrodynamics (SPH) and Arbitrary Lagrangian-Eulerian (ALE) methods to simulate fluid-soil interactions in both non-submerged and submerged environments. Analysis covers the flow fields and soil erosion. Findings show erosion velocity remains steady in non-submerged conditions, with the jet compacting and flushing soil. In submerged conditions, the simulated jet flow field under soil constraint is similar to that in the free submerged conditions. However, influenced by soil deformation, damage, and the backflow of the slurry, the jet flow field under soil constraint displays distinct features. For instance, velocity distributions in certain cross-sections cannot be accurately described by normal distribution, and axial velocity distribution curves exhibit different partitions compared to free submerged jet theory. Comparative simulations vary jet pressures, grout water-cement ratios, and soil compactness to analyze the erosion process. It is found that jet pressure significantly affects the depth of the erosion pit. The limit erosion distance in ALE simulations were compared with theoretical values derived from an established theory, and a model experiment was also conducted to analyze the jet-grouted diameter at different left speeds and rotational speeds of rod. The results show that ALE method can offer high accuracy in predicting the jet-grouted diameter and proves to be a feasible approach for fluid-soil interaction simulations in jet grouting. [ABSTRACT FROM AUTHOR]

Contemporary geoengineering challenges grapple with the plateauing of both existing algorithms and their depth of insights, a phenomenon exacerbated by the scarcity of high‐fidelity data. Although existing solutions such as Monte‐Carlo method can generate abundant data, they are not sufficiently robust for ensuring the high fidelity of data. This study proposes a novel data augmentation framework that combines statistical and machine learning methods to generate high‐fidelity synthetic data, which closely align with field data in terms of the statistical and empirical attributes. The innovations of the proposed approach lie in the integration of Copulas theory for data generation, a developed geo‐regression anomaly detection (GRAD) for adjusting data attributes, and an evolutionary polynomial regression for data consistency enforcement. The multilayer perceptron (MLP) and a wide‐and‐deep (WaD) networks are applied to assess the effectiveness of high‐fidelity data augmentation using jet grouting data. The outcomes reveal the robustness of the synthetic data generation framework, achieving satisfactory fidelity in both empirical and statistical attributes. The proposed data augmentation improved the R2 and MAE achieved by MLP and WaD up to 28.37% under data fractions ranging from 0.2 to 1. MLP and WaD yielded comparable results in terms of accuracy and generalization ability across various augmented fractions. This indicates that the accuracy of synthetic data plays a pivotal role, suggesting improving data quality can be highly effective in boosting performance, regardless of the model complexity. This study contributes valuable insights to addressing the challenges of scare high‐fidelity data in geoengineering. [ABSTRACT FROM AUTHOR]

Jet-grouting technique is one of the most widespread methods for soil reinforcement, used to make soil suitable to withstand forces transmitted by structures or the redistribution of stresses following excavations. The result of the treatment however is influenced by several factors, including type of treatment, type of soil, original stress state of the soil, machine operating parameters, and water-to-cement ratio. In particular, the strength of the treated material and its stiffness are very useful for designing the intervention for a specific case. Due to the uncertainty of the final strength and stiffness values, a test field is almost always required. But the design of the test field itself and the subsequent design of the intervention require some preliminary information on the expected values of the strength and the elastic modulus. An in-depth analysis of the scientific and technical literature was conducted, allowing for the selection of a significant number of cases. For each case, the type of treatment, the type of soil, uniaxial compressive strength (UCS), and elastic modulus (E) values were recorded. It was possible to determine the trend of the average UCS values and the E/UCS ratio for each type of analyzed soil and for the two studied jet-grouting techniques. In addition to the average values, the variability intervals, centered on the mean, capable of enclosing 90% of the data in the sample were identified. The obtained graphs represent a useful tool for obtaining a preliminary estimate of the strength and stiffness of the treated soil using the jet-grouting technique. [ABSTRACT FROM AUTHOR]

Protecting part of the zero cycles of multi-storey residential buildings built in areas with a complex geological structure and dense urban development from the negative effects of groundwater is one of the most important problems arising in modern urban planning. Although the specified groundwater level during engineering and geological surveys is considered when designing multi-story buildings, in many cases, the possibility of groundwater level changes due to natural-technogenic, physical-geological, physical-geographical, and anthropogenic factors is not considered. Therefore, after the buildings are constructed and put into operation, the parts of the building located below the zero level (car garage, basement, etc.) are exposed to the negative effects of groundwater. In addition to the discomfort caused by groundwater penetrating the foundations and other structural elements of multi-story buildings, depending on the degree of aggressiveness of these waters, they also cause wear and corrosion of reinforced concrete structural elements and generally reduce the service life of the building. The development of engineering protection measures to eliminate the aforementioned problems, prevent the causes of these problems, or minimize the negative impacts arising from these problems has become a necessary component of the construction process due to its relevance. The main objective of this article is to protect the zero-cycle structural elements of multi-story buildings from the negative impact of groundwater by using Jet Grouting technologies to prevent the aforementioned negative phenomena. The article is based on the results of real research and actual work performed. [ABSTRACT FROM AUTHOR]

This article investigates the challenges of maintaining the Machico Cable-Stayed Bridge in a marine environment, focusing on its implications for urban mobility. The primary problem addressed is the impact of harsh marine conditions on the structural integrity of the bridge, which poses significant challenges for ongoing maintenance and safety. The research highlights unique aspects such as the effects of saltwater exposure on materials and the interplay between infrastructure and urban transit dynamics. By emphasizing these critical issues, this study aims to provide insights into effective maintenance strategies and contribute to the broader discourse on urban mobility in coastal regions. [ABSTRACT FROM AUTHOR]

We address the challenges of limescale deposition and its management in urban construction sites, specifically within the Sumayil North project in Tel Aviv. Jet grouting, a method increasingly favored over conventional dewatering techniques for its minimal environmental impact and efficiency, is scrutinized for its unintended consequences on groundwater chemistry, particularly in relation to limescale formation. Our investigation centers on a dual approach: dissecting the geochemical dynamics leading to limescale deposition following jet grouting operations, and evaluating a remedial acid injection strategy implemented to counteract this phenomenon. We identify the critical factors influencing aquifer water chemistry through a detailed hydro-chemical analysis encompassing the Pleistocene Coastal Aquifer’s dynamics. The study reveals that the interaction between grout components and aquifer water significantly alters groundwater pH, driving the precipitation of calcium carbonate. The subsequent implementation of a sulfuric acid injection regimen successfully mitigated limescale accumulation, restoring pumping efficiency and neutralizing pH levels. We propose a workflow to manage and prevent limescale, emphasizing preemptive measures like custom grout compositions and controlled dewatering, with strict post-intervention groundwater monitoring. This approach balances operational efficiency, infrastructure integrity, and environmental stewardship in urban construction projects interfacing with sensitive aquifer systems.

We address the challenges of limescale deposition and its management in urban construction sites, specifically within the Sumayil North project in Tel Aviv. Jet grouting, a method increasingly favored over conventional dewatering techniques for its minimal environmental impact and efficiency, is scrutinized for its unintended consequences on groundwater chemistry, particularly in relation to limescale formation. Our investigation centers on a dual approach: dissecting the geochemical dynamics leading to limescale deposition following jet grouting operations, and evaluating a remedial acid injection strategy implemented to counteract this phenomenon. We identify the critical factors influencing aquifer water chemistry through a detailed hydro-chemical analysis encompassing the Pleistocene Coastal Aquifer's dynamics. The study reveals that the interaction between grout components and aquifer water significantly alters groundwater pH, driving the precipitation of calcium carbonate. The subsequent implementation of a sulfuric acid injection regimen successfully mitigated limescale accumulation, restoring pumping efficiency and neutralizing pH levels. We propose a workflow to manage and prevent limescale, emphasizing preemptive measures like custom grout compositions and controlled dewatering, with strict post-intervention groundwater monitoring. This approach balances operational efficiency, infrastructure integrity, and environmental stewardship in urban construction projects interfacing with sensitive aquifer systems. [ABSTRACT FROM AUTHOR]

In order to investigate the diffusion mechanism of slurry in post-pile grouting, this study develops a formula for calculating the diameter and the climb height of the cement core of jet grouting (CCJG). This research conducts field orthogonal tests using a self-developed grouting nozzle to analyze the effects of disturbance pressure (DP), disturbance time (DT), grouting pressure (GP), and the water–cement ratio (W/C) on the dimensions and strength of the CCJG. The findings revealed that the theoretical formula for calculating the diameter of the CCJG deviates by approximately 8% from the field test results, confirming the formula's validity. In addition, the DP and DT significantly influence the volume of the CCJG, displaying a linear increase with their augmentation. Conversely, the W/C and DP predominantly affect the CCJG's strength. Notably, an increase in the W/C results in diminished strength, whereas an increase in the DP enhances it. In addition, soil reinforcement is achieved through replacement, mixing, and compaction as the grout flows outward from the center of the grouting hole. These insights offer a theoretical foundation and technical support for effective grouting construction practices. [ABSTRACT FROM AUTHOR]

Jet grouting is one of the most popular soil improvement techniques, but its design usually involves great uncertainties that can lead to economic cost overruns in construction projects. The high dispersion in the properties of the improved material leads to designers assuming a conservative, arbitrary and unjustified strength, which is even sometimes subjected to the results of the test fields. The present paper presents an approach for prediction of the uniaxial compressive strength (UCS) of jet grouting columns based on the analysis of several machine learning algorithms on a database of 854 results mainly collected from different research papers. The selected machine learning model (extremely randomized trees) relates the soil type and various parameters of the technique to the value of the compressive strength. Despite the complex mechanism that surrounds the jet grouting process, evidenced by the high dispersion and low correlation of the variables studied, the trained model allows to optimally predict the values of compressive strength with a significant improvement with respect to the existing works. Consequently, this work proposes for the first time a reliable and easily applicable approach for estimation of the compressive strength of jet grouting columns.

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. [ABSTRACT FROM AUTHOR]

The recent construction of an underground mass rapid transit (MRT) station in Singapore involved 21 m deep excavations within underconsolidated marine clay. The lateral earth support system comprised 1 m thick diaphragm walls socketed into the underlying Old Alluvium and 4 levels of preloaded cross-lot struts. Deep soil mixing (DSM) and jet grouting piles (JGP) were used to improve up to 15 m thickness of the marine clay formation. Field monitoring data showed that these ground improvement processes caused large outward deflections of the diaphragm wall panels at some locations prior to the excavation and may have caused yielding within the wall panels. In this paper, the impacts of these prior wall deformations on the subsequent performance of the excavation support system are investigated. The measured performance at two indicative cross sections is compared with results from simplified 2D finite element analyses. The analyses simulate the effects of ground improvement through prescribed boundary pressures and represent the yielding of the diaphragm wall panels through zones of reduced bending stiffness. We show that large outward wall deflections and curvature observed during jet grouting at one section contribute to higher inward wall movements and strut loads measured during excavation, while smaller movements (and curvature) prior to excavation at a second similar cross section cause negligible change in the performance of the temporary earth retaining system. The results highlight (1) the importance of controlling ground movements associated with ground modification processes such as jet grouting, (2) the uncertainties in estimating mechanical properties for the improved soil mass, and (3) the need to improve the representation of non-linear, flexural properties (M-κ) of reinforced concrete diaphragm panels. [ABSTRACT FROM AUTHOR]

Jet grouting piles were widely employed for ground reinforcement in building and infrastructure engineering due to the low cost and construction convenience. However, this foundation treatment method is not allowed to be used in high-speed railway involved constructions in China because of the concerning of the negative effect on the lateral displacement of the existing high-speed railway. To find a reasonable application distance of jet grouting piles away from existing high-speed railway bridge in deep soft soils with medium sensibility, a series of laboratory and in-situ tests on the influence of the jet grouting piling on the deformation of surrounding soils and adjacent high-speed railway bridge are carried out. The geological characteristics of the construction site and the mechanical properties of the soft soil are deeply investigated by utilizing field and laboratory tests. The piling induced lateral displacement of the surrounding soils is monitored as well as the displacement of an adjacent high-speed railway bridge. The monitoring data reveal that the influence area of the jet grouting piling is approximately 1.75 ∼ 1.85 times of the pile length in deep soft soils. The critical distance of the jet grouting piles from the existing high-speed bridge should be larger than 2 times of the pile length.

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Deep soil mixing and jet grouting are in situ ground improvement techniques that are often used to enhance the stability of soft soil slopes for excavation and waterway projects. Although researchers have reported spatial variability in cement-treated ground, the literature on the influence of spatial variability on the stability of treated soil slopes is limited. In this study, the stability of a cement-treated soil slope is analyzed through two-dimensional random finite-element analysis, taking into consideration spatial variabilities in strength and unit weight of a cement-treated soil mass. Spatial parameters such as the mean strength µqu, coefficient of variation COV, horizontal scale of fluctuation SOFh, and vertical scale of fluctuation SOFv are varied, and the equivalent design strengths and strength reduction factors are calculated. Furthermore, strength reduction factors for isotropic (SOFh/SOFv = 1) and anisotropic (SOFh/SOFv = 7.5) spatially correlated random fields are calculated. The results show that an increasing value of SOFh has a worsening effect on stability up to a particular value, that is, approximately 2.0 times the slope width B, beyond which the influence does not appear to be significant. A strong logarithmic relationship between the SOFh/B ratio and the computed strength reduction factors is observed. Finally, a modified equation for the strength reduction factor is proposed; in this equation, the effect of the scale of fluctuation is considered by introducing an influence factor RSOF. For SOFh/B ratios ranging from 0.02 to 0.7, RSOF varies from 1.0 to approximately 2.0, indicating a significant effect of the scale of fluctuation. However, for SOFh/SOFv ranging from 1 to 7.5, RSOF varies slightly. [ABSTRACT FROM AUTHOR]

Jet grouting induces a complex interaction between soil and injected fluids, and thus the properties of columns are dictated by a combination of the two systems. Aiming to improve the efficiency of projects and optimize execution, past research has focused on the prediction of the column properties understanding the mechanisms underlaying treatment execution. For the complexity of phenomena and the uncertain determination of soil properties, the question can be only partially addressed on the theoretical level, being important answers left to the empiricism of field trials, i.e. full scale experiments carried out to test specific jet grouting solutions on specific sites. The present paper reports the results of a field experiment whose peculiarity consists in being conceived to investigate the role of technology on a wider spectrum. Single and double fluid injection systems with various parameters have been simultaneously performed on a subsoil characterized by in situ tests. Columns have then been discovered to measure their diameter and samples of cemented material have been cored and subjected to uniaxial compressive tests. Results are herein summarized and compared with literature solutions to point out strength and deficiencies of currently adopted conceptual models.

The paper is deals with the influence of thermal conductivity and the materials of the contact surfaces of the drill shaft and the sealing element on the change in the thermal balance of the structural unit «drilling string» used in the jet grouting technology to fix weak and unstable types of soils. A model with nodes for the computational grid of the “hydraulic puller” assembly unit is shown, part of which are the considered drill shaft and sealing elements. The temperature values are calculated by the finite element method in the «Siemens Femap’s» environment depending on the change in the thermal conductivity coefficients of the contacting elements. Calculations were carried out for the fourth part of the indicated model, due to the axisymmetry of the problem being solved, this made it possible to significantly reduce the amount and time of calculations. Graphs of the corresponding dependence are constructed for a number of points located in the characteristic areas of the hydraulic stripper. Also, by power regression, expressions were obtained that allow calculating the temperature values in the indicated areas of the considered assembly. The obtained dependencies will make it possible in the future to select the material for the drill shaft of the hydraulic puller based on the optimal ratio of the thermal conductivity of the shaft, its corrosion resistance, determined by the chemical composition of the steel and the thermal conductivity of the sealing.

The jet grouting method for soil improvement represents an innovative geotechnical alternative for problematic soils when the classic foundations’ designs cannot be appropriate, sustainable solutions for these soils. This study’s methodology was based on producing column models using a low-pressure injection laboratory setup designed and locally manufactured to approximate the field-equipment operation. The setup design was inspired by the works of previous researchers, where its functioning was validated by systematically performing unconfined compression tests (UCTs). Two soil improvement techniques were investigated, one by low-pressure injection of a mixture of water and ordinary Portland cement (OPC) with 0.8, 1, and 1.3 W/C ratios. The other type uses silica fume (SF) as a chemical additive with 10% of the cement weight added to the water and cement mix with 1, 1.3, and 1.6 W/C ratios. The study revealed that the UCT results of SF column model samples were higher than those of OPC with an equal W/C ratio. For each binder type, the UCT sample results increase with a decrease in the W/C ratio.

A floating storage and regasification unit (FSRU) terminal has been planned to be constructed in Saros Bay (Türkiye). This study presents the ground improvement method using jet grouting to prevent the liquefaction of marine sediments in the project area. An approach for performance assessment of jet column construction is also discussed. The study site has a liquefiable ground level with a thickness changing between 2 m and 8 m. Jet grout columns with an 80 cm diameter were constructed under the sea level, which varied between 4 m and 18 m for ground improvement. The main issue is controlling the quality and performance of these jet columns. Therefore, a practical quality control procedure containing observational, mechanical, and geophysical methods for offshore grouting operations was proposed. The factor of safety values against liquefaction varied between 0.04 and 0.29 for natural conditions, while the minimum factor of safety after jet column constructions was obtained as 1.01. The results of the numerical analyses showed that the constructed terminal has sufficient performance against liquefaction. Consequently, the results of these methods have demonstrated that the jet grout applications performed by following this procedure are a suitable and effective improvement method for offshore soils. [ABSTRACT FROM AUTHOR]

In order to investigate the diffusion mechanism of slurry in post-pile grouting, this study develops a formula for calculating the diameter and the climb height of the cement core of jet grouting (CCJG). This research conducts field orthogonal tests using a self-developed grouting nozzle to analyze the effects of disturbance pressure (DP), disturbance time (DT), grouting pressure (GP), and the water–cement ratio (W/C) on the dimensions and strength of the CCJG. The findings revealed that the theoretical formula for calculating the diameter of the CCJG deviates by approximately 8% from the field test results, confirming the formula’s validity. In addition, the DP and DT significantly influence the volume of the CCJG, displaying a linear increase with their augmentation. Conversely, the W/C and DP predominantly affect the CCJG’s strength. Notably, an increase in the W/C results in diminished strength, whereas an increase in the DP enhances it. In addition, soil reinforcement is achieved through replacement, mixing, and compaction as the grout flows outward from the center of the grouting hole. These insights offer a theoretical foundation and technical support for effective grouting construction practices.

Copyright of Österreichische Wasser- und Abfallwirtschaft is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Archives of Civil Engineering (Polish Academy of Sciences) is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study presents an improved random forest (IRF) model to evaluate the ground displacement caused by jet grouting. The proposed IRF model integrates a new hybrid particle swarm optimization-simulated annealing (PSO-SA) algorithm into random forest. The performance of the PSO-SA optimizer is investigated using a set of 8 benchmark functions; whereas, three benchmark models are used to test the IRF model. The results show that PSO-SA has much better searching and convergence abilities than its counterparts (PSO and SA). When the IRF was applied to predict ground displacement, the IRF model outperforms the benchmarks models. Moreover, the out-of-bag variable importance analysis shows that the ground lateral displacement resulting from jet grouting operations can be controlled through two operating parameters, namely, the retract rate of monitor and injected fluid pressure. The high accuracy and flexibility of the proposed model make it suitable for other engineering applications regardless of their complexity. [ABSTRACT FROM AUTHOR]

Soil improvement has developed as a realistic solution for enhancing soil properties so that structures can be constructed to meet project engineering requirements due to the limited availability of construction land in urban centers. The jet grouting method for soil improvement is a novel geotechnical alternative for problematic soils for which conventional foundation designs cannot provide acceptable and lasting solutions. The paper's methodology was based on constructing pile models using a low-pressure injection laboratory setup built and made locally to simulate the operation of field equipment. The setup design was based on previous research that systematically conducted unconfined compression testing (U.C.Ts.). The soil improvement techniques were investigated by injecting a low-pressure mixture of water and ordinary Portland cement (O.P.C.) with (0.8, 1, and 1.3) W/C ratios. The study revealed the relationship between pile model samples (U.C.Ts.) and W/C ratios. It also showed that the pile model samples' (U.C.Ts.) result decreased from 14 to 12 to 10 MPa, respectively, with an increase in W/C ratios from 0.8 to 1 and 1.3, respectively. Furthermore, the stiffness characteristics of a jet grouting column were calculated based on Mohr's Circles theory, and numerous theoretical approaches obtained the consequences of tensile strength.

This paper presents a case study of an investigation into the responses of the surrounding soil to the continuous jet grouting in soft soil deposits of Ningbo. During the field test, an automatic intelligent monitoring system was set up to monitor vertical and lateral displacement of ground surface, lateral displacements of the subsurface soils, and the variation of pore-water pressure induced by the installation of jet grouting piles (JGPs). The monitoring results showed that the construction of the jet grouting piles caused a large deformation of the surrounding soil. At a distance of 1.5 m from the construction area, the maximum vertical displacement and horizontal displacement could reach 179.54 mm and 180.31 mm. With the increase of distance, although the influence gradually weakened, the values of the two were still 5.8 mm and 18.98 mm at a distance of 15 m from the construction area. The excess pore pressure of the surrounding soil caused by the construction could reach 124.9 kPa. Notably, the construction of the rotary jet pile has a great influence on the surrounding soil. The installed piles can reduce the impact of the installation of the following piles. In soft soil foundation, the influence of jet grouting cannot be mitigated by stress relief holes. [ABSTRACT FROM AUTHOR]

The dynamic action of groundwater in the water-rich sand stratum carries away injected cement slurry before it becomes solidified, which seriously affects the determination of the diameter and strength of the column. Grouting additives and information-based construction are two main actions to control the quality of jet grouting construction. This study introduced a solution of grouting additives and information-based construction of jet grouting in the water-rich sand stratum. First, high-polymer cement grout (HPCG), red mud and phosphogypsum cement grout (RPCG) and metakaolin cement grout (MKCG) additives were screened with a series of laboratory tests on solidification time and permeability; moreover, the mix proportion of grouting fluids was developed in order to adapt for water-rich sand strata. Secondly, information-based construction of jet grouting was conducted to control grouting quantity with real-time monitoring of drill rotational velocity, drill lifting speed and injection pressure equipped with the monitoring system on the double fluid jet grouting systems. Lastly, the validity of grouting additives and information-based construction in the water-rich sand stratum was verified via a test pile in situ, and a series of material tests on drilling core samples on permeability with SEM observation. The results indicate that the high polymer is the preferred additive of grouting fluids because the solidification time can be controlled in the range of 10 min to 20 min; the permeability of drilling core samples can reach the order of 10−7, with the mix proportion being A:B = 2:1, high-polymer additive:water > 1:3, with a water-cement ratio of 0.8. The specifications of information-based construction are a drill rotational velocity of 10 r/min, a drill lifting speed of 0.2 m/min, an injection pressure of 20 MPa and a grouting quantity of 40 L/min. [ABSTRACT FROM AUTHOR]

The soil tunnel in Drammen (Norway), part of Bane NOR's 'New Double Track Drammen–Kobbervikdalen' project, has a length of 290 m; however, the different unfavourable boundary conditions combined with a large excavation cross section (156 m2) make this section the most technically challenging part of the project. The soil tunnel is driven mostly in saturated glaciofluvial sediments, which consist primarily of sand and gravel with a low content of fines, resulting in a low cohesion to cohesionless soil. The groundwater level, always within or above the tunnel section, cannot be lowered during the construction due to project requirements. These geological/hydrogeological conditions together with the large cross section present a high‐risk scenario for any tunnelling project and, in the case of Norway, an unprecedented challenge. Moreover, the tunnel is located in an urban area and has a low overburden of just 8 to 9 m during the first 80 m. For the client it was critical that the design solution was safe, robust, and able to respond to the existing level of uncertainty and potential unexpected occurrences. ILF's design is able to answer these technical challenges while removing many of the typical risks associated to saturated soil tunnelling with a solution that relies mainly on extensive pre‐excavation ground improvement works in the form of jet grouting executed from the surface. [ABSTRACT FROM AUTHOR]

This paper presents the determination of the rheological properties of cement grouts and the examination of the model jet grouting (JG) columns produced in the laboratory. Fine-grained cement (DMFC-800), ordinary Portland cement (CEM I), natural pozzolana admixtured cement (CEM II) and blast furnace slag (BFS) admixtured cement (CEM III) types were used. Grout mixtures with various water/cement (W/C) ratios were prepared and rheological tests were performed. Effects of cement characteristics and rheological properties of cement grouts on column dimensions, soilcrete strength were researched. Columns with the largest diameter were obtained with DMFC-800 cement. The primary parameter affecting the JG column diameter was cement grain size and the secondary parameter was grout viscosity. CEM III cement provided the highest compressive strength (28.5 MPa) in the long term. DMFC-800 provided remarkable strength (2–5 MPa) even with grouts containing high amount of water (W/C = 2.0–3.0). Grout stability affected the homogeneity of the soilcrete structure. [ABSTRACT FROM AUTHOR]

A novel and effective artificial neural network (ANN) optimized using differential evolution (DE) is first introduced to provide a robust and reliable forecasting of jet grouted column diameters. The proposed computational method adopts the DE algorithm to tackle the difficulties in the training and performance of neural networks and optimize the four quintessential hyper-parameters (i.e. the epoch size, the number of neurons in a hidden layer, the number of hidden layers, and the regularization parameter) that govern the neural network efficacy. This approach is further enhanced by a stochastic gradient optimization algorithm to allow ‘expensive’ computation efforts. The ANN-DE is first trained using a prepared jet grouting dataset, then verified and compared with the prevalent machine learning tools, i.e. neural networks and support vector machine (SVM). The results show that, the ANN-DE outperforms the existing methods for predicting the diameter of jet grouting columns since it well balances training efficiency and model performance. Specifically, the ANN-DE achieved root mean square error (RMSE) values of 0.90603 and 0.92813 for the training and testing phases, respectively. The corresponding values were 0.8905 and 0.9006 for the optimized ANN, then, 0.87569 and 0.89968 for the optimized SVM, respectively. The proposed paradigm is bound to be useful for solving various geotechnical engineering problems regardless of multi-dimension and nonlinearity.

A floating storage and regasification unit (FSRU) terminal has been planned to be constructed in Saros Bay (Türkiye). This study presents the ground improvement method using jet grouting to prevent the liquefaction of marine sediments in the project area. An approach for performance assessment of jet column construction is also discussed. The study site has a liquefiable ground level with a thickness changing between 2 m and 8 m. Jet grout columns with an 80 cm diameter were constructed under the sea level, which varied between 4 m and 18 m for ground improvement. The main issue is controlling the quality and performance of these jet columns. Therefore, a practical quality control procedure containing observational, mechanical, and geophysical methods for offshore grouting operations was proposed. The factor of safety values against liquefaction varied between 0.04 and 0.29 for natural conditions, while the minimum factor of safety after jet column constructions was obtained as 1.01. The results of the numerical analyses showed that the constructed terminal has sufficient performance against liquefaction. Consequently, the results of these methods have demonstrated that the jet grout applications performed by following this procedure are a suitable and effective improvement method for offshore soils.