scholarly journals Visual evaluation of relative deep mixing method type of ground-improvement method

2021 ◽  
pp. 100233
Author(s):  
Koki Nakao ◽  
Shinya Inazumi ◽  
Toshiaki Takaue ◽  
Shigeaki Tanaka ◽  
Takayuki Shinoi
Keyword(s):  
Ground Improvement ◽  
Visual Evaluation ◽  
Deep Mixing ◽  
Improvement Method ◽  
Mixing Method

scholarly journals Evaluation of Discharging Surplus Soils for Relative Stirred Deep Mixing Methods by MPS-CAE Analysis

2021 ◽  
Vol 14 (1) ◽  
pp. 58
Author(s):  
Koki Nakao ◽  
Shinya Inazumi ◽  
Toshiaki Takaue ◽  
Shigeaki Tanaka ◽  
Takayuki Shinoi
Keyword(s):  
Simulation Analysis ◽  
Ground Improvement ◽  
Normal Type ◽  
Deep Mixing ◽  
Improvement Measures ◽  
Improvement Method ◽  
Mixing Method ◽  
Cae Analysis ◽  
Great Damage

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 evaluation of the performance of the ground-improvement work was conducted in this study. The authors performed a simulation analysis of the relative stirred deep mixing method (RS-DMM), a kind of ground-improvement method, using a computer-aided engineering (CAE) analysis based on particle-based methods (PBMs). In the RS-DMM, the “displacement reduction type (DRT)” suppresses displacement during construction. Both the DRT and the normal type (NT) were simulated, and a visible and measurable evaluation was performed on the internal conditions during each construction, the quality of the improved body, and the displacement reduction performance. As an example of these results, it was possible to visually evaluate the discharge of surplus soil by the spiral rod attached to the stirring wing of the DRT. In addition, the authors succeeded in quantitatively showing that more surplus soil was discharged when the stirring wing of the DRT was used than when the stirring wing of the NT was used.

scholarly journals Deep mixing method for the construction of earth and water retaining walls

2017 ◽  
Vol 2 ◽  
pp. 1-9 ◽  
Author(s):  
Nicolas Denies ◽  
Noël Huybrechts
Keyword(s):  
Large Scale ◽  
Ground Improvement ◽  
Retaining Walls ◽  
Bending Tests ◽  
Deep Mixing ◽  
Soil Cement ◽  
Mixing Method ◽  
Cement Mixture ◽  
Soil Mix ◽  
Steel Section

In the deep mixing method, the ground is mechanically mixed in place while a binder, often based on cement, is injected. After hardening of the soil-cement mixture, called soil mix material, soil mix elements are formed in the ground. Originally known as a ground improvement technique, the deep mixing is more and more applied for the construction of earth-water retaining structures within the framework of excavation works. After a short introduction to the execution aspects of the method, the authors discuss the hydro-mechanical properties of the soil mix material mainly based on the results of the BBRI Soil Mix project (2009-2013). A design approach dedicated to the soil mix retaining walls and developed in collaboration with the SBRCURnet is then presented. In this methodology, which is in line with the structural Eurocodes, design rules are adapted to the functions of the soil mix wall (earth-water retaining, bearing and cut-off functions) including the temporary or permanent character of the application. Based on the result of large-scale bending tests, the interaction between the soil mix material and the steel reinforcement is considered in the calculations allowing a reduction of the steel section between 10 and 40 %.

INVESTIGATION ON THE EFFECT OF COUNTERMEASURES FOR SUBSIDENCE AT THE APPROACHING AREAS OF ABUTMENTS

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Yukihide Kajita ◽  
Kazuki Onoda ◽  
Taiji Matsuda ◽  
Kunihiko Uno ◽  
Takeshi Kitahara
Keyword(s):  
Seismic Analysis ◽  
Ground Improvement ◽  
Bending Moment ◽  
Soil Improvement ◽  
Ground Subsidence ◽  
The Third ◽  
Deep Mixing ◽  
Emergency Vehicles ◽  
Mixing Method

The purpose of this study is to confirm the effect of soil improvement methods on preventing ground subsidence at the back of abutments. Earthquake seismic analysis is performed for three models. One is a model with no ground improvement. Next is a model with deep mixing method. The third is the model with lightweight banking method. As a result, from the perspective of the passage possibility of the emergency vehicles, both the deep mixing method and lightweight banking method are effective in preventing ground subsidence at the approaching area of abutments. However, in the case of the deep mixing method, it is found that the maximum bending moment of the pile under the liquefaction layer increases because a lump of improved rigid soil that falls down toward the piles.

Test on Cement Deep Mixing Soil Strength

2013 ◽  
Vol 401-403 ◽  
pp. 738-742
Author(s):  
Jin Fang Hou ◽  
Ming Ying Li
Keyword(s):  
Ground Improvement ◽  
Soft Clay ◽  
Treatment Method ◽  
Soil Strength ◽  
Design Strength ◽  
Deep Mixing ◽  
Ground Treatment ◽  
Mixing Method ◽  
Clay Ground ◽  
Cement Deep Mixing

Cement deep mixing method is a normal ground treatment method. However, it is less applied on the soft clay ground improvement. The test was carried out to the strength of cement mixing soft clay. The soft clay was mixed with cement to become cement mixing soil. The strength of cement mixing soil was analyzed at different maintenance ages. As the results, the strength was lower than the anticipation value. After mixing additive, the strength of cement mixing soil increased, but it still wasnt reached the design strength demand. So, the cement deep mixing method is careful to be as a ground treatment method for the project with thick soft clay ground and high design strength.

scholarly journals Numerical Analysis on Performance of the Middle-Pressure Jet Grouting Method for Ground Improvement

Geosciences ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 313
Author(s):  
Shinya Inazumi ◽  
Sudip Shakya ◽  
Takahiro Komaki ◽  
Yasuharu Nakanishi
Keyword(s):  
Life Cycle ◽  
Comparative Analysis ◽  
Ground Improvement ◽  
Cement Slurry ◽  
Mechanical Agitation ◽  
High Quality ◽  
Jet Grouting ◽  
Computer Aided ◽  
Improvement Method ◽  
Cae System

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 mechanical agitation and mixing, a comparative analysis was performed with different jet pressures, the development situation was visualized, and the performance of this method was evaluated. The results of MPS-CAE as one of the CAE systems showed that the cement slurry jet ratio in the planned improvement range, including the periphery of the mixing blade, by the middle-pressure jet grouting together with the mechanical agitation and mixing was increased and a high quality columnar soil-improved body was obtained. It is expected that the introduction of CAE will contribute to the visualization of the ground, and that CAE will be an effective tool for the visual management of construction for ground improvement and the maintenance of improved grounds during the life cycle of the ground-improvement method.

Uplift and Settlement Prediction Model of Marine Clay Soil e Integrated with Polyurethane Foam

2019 ◽  
Vol 9 (1) ◽  
pp. 481-489
Author(s):  
D.C. Lat ◽  
I.B.M. Jais ◽  
N. Ali ◽  
B. Baharom ◽  
N.Z. Mohd Yunus ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Clay Soil ◽  
Ground Improvement ◽  
Soft Soil ◽  
Soft Clay ◽  
Effective Thickness ◽  
Marine Clay ◽  
Uplift Pressure ◽  
Pu Foam ◽  
Improvement Method

AbstractPolyurethane (PU) foam is a lightweight material that can be used efficiently as a ground improvement method in solving excessive and differential settlement of soil foundation mainly for infrastructures such as road, highway and parking spaces. The ground improvement method is done by excavation and removal of soft soil at shallow depth and replacement with lightweight PU foam slab. This study is done to simulate the model of marine clay soil integrated with polyurethane foam using finite element method (FEM) PLAXIS 2D for prediction of settlement behavior and uplift effect due to polyurethane foam mitigation method. Model of soft clay foundation stabilized with PU foam slab with variation in thickness and overburden loads were analyzed. Results from FEM exhibited the same trend as the results of the analytical method whereby PU foam has successfully reduced the amount of settlement significantly. With the increase in PU foam thickness, the settlement is reduced, nonetheless the uplift pressure starts to increase beyond the line of effective thickness. PU foam design chart has been produced for practical application in order to adopt the effective thickness of PU foam within tolerable settlement value and uplift pressure with respect to different overburden loads for ground improvement works.

Cased-Pipe Sampling for Quality Assurance of Deep Mixing Method: A Case Study

Grouting 2017 ◽  
2017 ◽  
Author(s):  
Ignazio Paolo Marzano ◽  
Massimo Grisolia ◽  
Giuseppe Iorio ◽  
Giuseppe Panetta ◽  
Raffaele Papa
Keyword(s):  
Quality Assurance ◽  
Deep Mixing ◽  
Mixing Method

Study on Artificial Island Ground Improvement Method and Effect

2014 ◽  
Vol 1030-1032 ◽  
pp. 1037-1040
Author(s):  
Jin Fang Hou ◽  
Ju Chen ◽  
Jian Yu
Keyword(s):  
Pore Water Pressure ◽  
Water Pressure ◽  
Ground Improvement ◽  
Soft Soil ◽  
Horizontal Displacement ◽  
Treatment Method ◽  
Surcharge Preloading ◽  
Porosity Ratio ◽  
Improvement Method ◽  
Consolidation Degree

The artificial island ground on an open sea is covered by thick soft soil. It must be improved before using. In accordance with a designing scheme, the ground treatment method is inserting drain boards on land and jointed dewatering surcharge preloading, the residual settlement is not more than 30cm after improvement and the average consolidation degree is more than 85%. In order to estimate ground improvement effect and construction safety, instruments are buried to monitor the whole ground improving processes. By monitoring settlement and pore water pressure, it is shown that the total ground settlement in construction is 2234mm, its final settlement is 2464mm, and consolidation degree and residual settlement respectively satisfy requirements. In ground improvement, horizontal displacement is small and construction is safe. Meanwhile, the results of soil properties and vane shear strength detection tests show the soft soil ground is greatly reduced in water content and porosity ratio, and improved in strength. It is named that the ground improvement method is reasonable and reaches expected effect.

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