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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 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 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]

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 article proposed a new method to estimate the diameter of jet grouting columns. The method uses the largest data collection of column diameters measured to date and includes a large amount of new data that fills the existing gap of data for high injection energies. The dataset was analysed using a deep neural network that took into account the problem's key parameters (i.e. type of soil, soil resistance, type of jet and specific energy in the nozzle). As a result, three different neural networks were selected, one for each type of jet, according to the errors and consistency associated with each. Finally, using the trained networks, a number of design charts were developed to determine the diameter of a jet grouting column as a function of the soil properties and the jet system. These charts allow generating an optimal jet grouting design, improving the prediction of the diameter of jet columns especially in the high energy triple fluid. [ABSTRACT FROM AUTHOR]

One of the damages caused by earthquakes in engineering structures is soil liquefaction-induced damages. Because of the many factors that affect the liquefaction mechanism of soils, the assessment of liquefaction potential is a rather complex problem. In the earthquake, it is the necessary to determine the liquefaction sensitivity of soils and take precautions by estimating possible effects. The stress-based liquefaction analysis, which is the commonly used to determine the liquefaction susceptibility of the soils, has been included in the new Turkish Building Earthquake Code (TBEC). In the usage of this method, the numerous parameters such as the earthquake characteristics, the soil properties, the in-situ and underground water conditions, the properties of equipment used during field studies are needed. Due to the excessive number of parameters and empirical expressions used in the analysis, significant errors can sometimes cause in the soil investigation reports in practice. In this study, in order to make practical use of liquefaction analysis based on standard penetration test defined in TBEC, and to control quickly the performed analyses, the graphics that give the factor of safety against liquefaction of sandy soils were prepared for different depths, groundwater levels, fine contents, and SPT-N values. In addition, cards were developed to determine design parameters such as the stiffness of the columns to be used in the column formation method and the column spacing to be used for the improvement of the liquefiable soils.

This paper presents a generalized approach for predicting the diameter of jet grout columns based on the theoretical framework of turbulent kinematic flow and soil erosion. The proposed calculation method is applicable to all conventional jet-grouting systems and takes into account the full range of operational parameters, fluid properties, soil strength, and particle size distribution, including the effect of the injection time on erosion distance. It was demonstrated that the increase in the jet grout column diameter arising from the use of a compressed air shroud in the double and triple fluid systems is approximately 27-81% for the typical range of air pressure of 0.5-1.5 MPa. The proposed method was applied to four case histories involving four variants of jet-grouting systems, i.e., single fluid, double fluid, triple fluid, and an enhanced triple fluid system. Comparison between the calculated and the measured jet grout column diameters indicated that the proposed method can produce reasonable predictions for a variety of soil conditions. It was shown that jet grout columns formed by the enhanced triple fluid system are larger than those formed by the conventional triple fluid system by approximately 36% on average. The proposed generalized approach allows all the key variables to be considered and is a useful means for the design of ground improvement by jet grouting. [ABSTRACT FROM AUTHOR]

Abstract: Jet grouting (JG) is a soil treatment technique which is the best solution for several soil improvement problems. However, JG lacks design rules and quality controls. As a result, the main JG works are planned from empirical rules that are too conservative. The development of rational models to simulate the effects of the different parameters involved in the JG process is of primary importance in order to satisfy the binomial safety-economy that is required in any engineering project. In this paper, we present a new approach to predict the uniaxial compressive strength (UCS) of JG materials based on data mining techniques. This model was developed and verified using data from a JG laboratory formulation that involves the measurement of UCS. The results of the proposed approach are compared with the EC2 analytical model adapted to the JG material, and the advantages of the new approach are highlighted. We show that the novel data-driven model is able to learn (with high accuracy) the complex relationships between the UCS of JG material and its contributing factors. [Copyright &y& Elsevier]

Abstract: Jet grouting is a method for improving soil characteristics. In this method, grouting of cement slurry with high pressure and velocity causes damage to soil structure. Excavated grains of soil are then removed from the borehole and are replaced with cement slurry. The grains that remain around the borehole mix with cement slurry and produce an improved soil mass of soil. This mass is called “soilcrete”. Soilcrete has special characteristics such as high strength, low deformability and very low permeability. The jet grouting process and its results are affected by various parameters of the soil material and jet grouting system. This paper discusses the effects of jet grouting process on the soil properties before and after the operations, and the effects of grout pressure and grout flow on soilcrete''s uniaxial compression strength (UCS). For these purposes, five types of the laboratory tests have been done on the jet grouted soil: uniaxial compression, triaxial compression, direct shear, Brazilian indirect tension, and Schmidt hammer tests. According to the numerical results obtained from experiments, by increasing the grout pressure and flow, the UCS (MPa) of soil increases logarithmically. In addition, jet grouting dramatically increases properties such as cohesion and friction angle. [Copyright &y& Elsevier]