Ground Improvement for Large Above Ground Tanks Using Deep Mixing

2000 ◽  
Author(s):  
Eric W. Bahner ◽  
Aiman M. Naguib
Keyword(s):  
Ground Improvement ◽  
Deep Mixing

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 Effect of Deep Mixing Grid Spacing On The Settlement of Liquefied Soil, Using Numerical Approach

2022 ◽  
Author(s):  
Fereshteh Rahmani ◽  
Seyed Mahdi Hosseini
Keyword(s):  
Pore Pressure ◽  
Ground Improvement ◽  
Pressure Ratio ◽  
Soil Layer ◽  
Excess Pore Pressure ◽  
Analysis Model ◽  
Liquefaction Mitigation ◽  
Deep Mixing ◽  
Liquefiable Soil ◽  
Excess Pore

Abstract Liquefaction occurs in a loose and saturated sand layer, induces quite large damages to infrastructures, the importance of liquefaction mitigation has been emphasized to minimize earthquake disasters for many years. Many kinds of ground improvement techniques based on various improvement principles have been developed for liquefaction mitigation. Among them, deep mixing method with grid pattern was developed for liquefaction mitigation in the 1990s, where the grid of stabilized column walls functions to restrict the generation of excess pore pressure by confining the soil particle movement during earthquake. In this study, a parametric study of the grid-form deep mixing wall is performed using numerical modeling with GID+OpenSees interface V2.6.0. The finite element method with a three-dimensional analysis model can be used to estimate the foundation settlement over liquefiable soil layer. The validity of the developed model was evaluated by comparing the results obtained from the model with the results of numerical studies and the experimental centrifuge test to investigate the effect of deep mixing grid wall on the settlement and generation of excess pore pressure ratio of liquefiable soil. Based on the analysis, the settlement for improved soil was 69% smaller than the settlement for unimproved soil. The results also indicated that the grid wall space, relative density, and stiffness ratio between soil-cement columns and enclosed soil plays an important role in the occurrence of liquefaction and volumetric strains.

Optimization of strength and homogeneity of deep mixing material by the determination of workability limit and optimum water content

2013 ◽  
Vol 50 (10) ◽  
pp. 1034-1043 ◽  
Author(s):  
Fabien Szymkiewicz ◽  
Friede-Stéphanie Tamga ◽  
Alain Le Kouby ◽  
Philippe Reiffsteck
Keyword(s):  
Water Content ◽  
Cement Content ◽  
Ground Improvement ◽  
Clay Content ◽  
Liquid Limit ◽  
Soil Mixing ◽  
Deep Mixing ◽  
Optimum Water Content ◽  
New Applications ◽  
Optimum Water

With ongoing development of the “deep mixing method”, the scope of applications is always widening. Once confined to ground improvement applications (i.e., to ensure stability and reduce settlements of structures on soft soils), use of this method now ranges from cut-off walls to structural elements and retaining walls. Indeed, the execution is easier, with limited excavated material, and costs less than traditional methods. With these new applications, the required hydraulic and mechanical properties of the soil-mixing material have also evolved, and numerous investigations on the hardened material have been carried out. However, properties of the material in a fresh state must be studied too, and particularly its workability because it is essential for continuity and homogeneity purposes. A laboratory program was carried out to determine the workability evolution of the material with increase of cement content. Results show that the material’s workability limit varies greatly with cement content, and that at constant dosage the clay content still controls the evolution of the material liquid limit. Also, this paper shows a method to determine the optimum water content for the deep mixing material, meaning that instructions can be given on site to ensure that optimum mechanical characteristics are reached.

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.

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