scholarly journals Analysis of Causes of CFG Pile Necking in Saturated Soft Soil Layer and Its Control Measures

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Wang Hang
Keyword(s):  
Fly Ash ◽  
Soft Soil ◽  
Soil Layer ◽  
Reference Value ◽  
Composite Foundation ◽  
Control Measures ◽  
Effective Control ◽  
Foundation Treatment ◽  
Soft Foundation ◽  
Cfg Pile

In recent years, composite foundation technology has been widely used in foundation treatment. Composite foundation theory has become an important research topic in the field of geotechnical engineering. CFG pile (Abbreviation of cement, fly ash, and gravel pile) in composite foundation is one of the commonly used technologies. It has advantages such as simple construction, reliable quality and low cost. When it is used in soft foundation treatment, it significantly improves the bearing capacity, reduces settlement, and turns waste (fly ash) to treasure, which benefits economic and social significantly. During construction, various defects in construction quality will affect the effect of soft foundation treatment. CFG pile necking is one of the more representative quality defects. This paper combined some project examples to analyze the causes of CFG pile necking and develop effective control measures for it which has a certain reference value towards the quality control of the technology

The Experimental Research on the Bag-Grouting-Pile Composite Foundation in Coastal Soft Foundation Treatment

2013 ◽  
Vol 275-277 ◽  
pp. 1411-1414
Author(s):  
Dong Wang ◽  
Jia Cao
Keyword(s):  
Experimental Research ◽  
Soft Soil ◽  
Cost Effective ◽  
Horizontal Displacement ◽  
Composite Foundation ◽  
Soil Reinforcement ◽  
Treatment Technology ◽  
Ground Treatment ◽  
Foundation Treatment ◽  
Soft Foundation

As a new ground treatment technology, the bag-grouting-pile composite foundation is used in railway soft soil reinforcement. In this paper, the application effect of bag-grouting-pile in coastal soft foundation treatment was studied in this experimental research; the deep settlement and the deep horizontal displacement of embankment edge in bag-grouting-pile composite foundation are tested in the research. The results of research show that the bag-grouting-pile composite foundation is a cost-effective ground treatment technology using in coastal soft foundation treatment.

An Analysis on Failure Pattern of CFG Pile-Net Composite Foundation of High-Speed Railway

2012 ◽  
Vol 594-597 ◽  
pp. 1357-1362
Author(s):  
Dan Ping Jiang ◽  
Bing Long Wang
Keyword(s):  
High Speed ◽  
Shear Failure ◽  
Soft Soil ◽  
Composite Foundation ◽  
Failure Pattern ◽  
Lagrangian Analysis ◽  
High Speed Railway ◽  
Foundation Treatment ◽  
Sliding Soil ◽  
Cfg Pile

CFG pile-net composite foundation has the advantages of small post construction settlement and uneven settlement, easy control of construction quality and fast construction speed. It`s widely used in subgrade engineering of high-speed railway. However, in coastal soft soil area, phenomena like breaking pile, collapsed embankment, cracking in embankment surface, undue settlement or convergence appeared in many places where railway CFG pile was improved during the foundation treatment, filling and preloading. Four numerical calculations were performed to investigate the failure pattern of CFG pile-net composite foundation with FLAC3D ( Fast Lagrangian Analysis of Continua, 3 dimensions) software. The paper describes four failure pattern, they are slip circle shear failure, pile tilt failure, roadbed sliding, soil sliding at pile end respectively through the analysis of the embankment and pile displacement as well as embankment deformation.

The Settlement Analysis of the Cement Fly-Ash Gravel Pile Composite Foundation of Baotou

2014 ◽  
Vol 580-583 ◽  
pp. 518-523
Author(s):  
Juan Li ◽  
Yao Xu ◽  
Jun Yin
Keyword(s):  
Fly Ash ◽  
Composite Foundation ◽  
Settlement Calculation ◽  
Practical Engineering ◽  
Cfg Pile Composite Foundation ◽  
Modified Formula ◽  
Gravel Pile ◽  
Final Settlement ◽  
Settlement Analysis ◽  
Cfg Pile

This paper analyzes the causes of larger differences of final settlement calculated value of cement fly-ash gravel pile (CFG pile) composite foundation of Baotou with actual observed result of it. On the basis of analysis on a number of practical engineering data of Baotou, we modify the settlement formula of the CFG pile composite foundation and gain the modified coefficient applied to the settlement calculation of the CFG pile composite foundation of Baotou. The modified formula and coefficient proposed in this paper have a positive effect on the accurate settlement calculation of puting forward a more accurate correction formula and coefficient of the calculation of the CFG pile composite foundation of Baotou.

Application and Research on New Technology of Foam Lightweight Soil in Treatment of Soft Soil Foundation of Railway Engineering

2012 ◽  
Vol 204-208 ◽  
pp. 1622-1625 ◽  
Author(s):  
Zi Lin Li ◽  
Kai Feng Zhang
Keyword(s):  
New Technology ◽  
Soft Soil ◽  
Actual Application ◽  
Foundation Treatment ◽  
Soft Foundation ◽  
Depth Analysis ◽  
Depth Study ◽  
New Ideas ◽  
Soil Foundation ◽  
Soft Soil Foundation

Foam lightweight soil is a new type of material appearing in recent years, whose advantages are paid more and more attention to by engineers and it will have broad application prospect in the engineering. An in-depth study application of foam lightweight soil in the complex of railway soft soil foundation treatment what based on a railway foundation project in Tianjin, this paper discusses the actual application state of foam lightweight soil in handling of special railway soft soil foundation. Through in-depth analysis of the advantages of a foam lightweight soil, optimization of construction replacement thickness and moisture density, discussion on construction of it, we can find large advantages of foam lightweight soil as replacement material in the complex railway soft soil foundation treatment, and provide new ideas about processing complex soft foundation.

The Numerical Analysis of CFG Pile Technology in the Disposing Soft Foundation in GuangWu Expressway

2011 ◽  
Vol 90-93 ◽  
pp. 2096-2100
Author(s):  
Yun Mei Meng ◽  
Yun Cao
Keyword(s):  
Numerical Analysis ◽  
Soft Soil ◽  
Influence Factors ◽  
Computational Results ◽  
Soft Foundation ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Cfg Pile

The problem of disposing the soft soil foundation will appear inevitably during the construction of modem high way. There are many ways to dispose the soft foundation. One of those is CFG pile technology. Take the CFG pile technology in the GuangWu Expressway for example, the influence factors of embankment settlement were discussed in detai by numerical analysis, some useful conclusions are obtained from the computational results.

The Influence of Pavement Construction on Embankment Settlement in Highway Extension Project

2013 ◽  
Vol 361-363 ◽  
pp. 1787-1793
Author(s):  
Xian Lin Wei ◽  
Yi Min Wang ◽  
Ze Min Zeng ◽  
Luo Zhang
Keyword(s):  
Soft Soil ◽  
Soil Layer ◽  
Composite Foundation ◽  
Standard Requirement ◽  
Construction Period ◽  
Small Influence ◽  
Load Carrying ◽  
Pavement Construction ◽  
Layer Deformation

In order to reduce the soft soil layer deformation due to pavement construction, equal preloading of pavement is usually adopted after embankment filling in soft ground region. But as the ground treatment effect of pile-supported and geosynthetic reinforced embankment is satisfactory with great load-carrying ability, the necessity of applying equal preload is worth discussing. Combined with the practice of Guangzhou-Sanshui expressway widening project, the settlements in surveying sections during the paving construction period in extension area were monitored. The monitoring data shows that pavement load had small influence on embankment settlement: the uneven settlement between newly widen and existing road is small and the post-construction settlements are controlled within the standard requirement. On the premise of guaranteeing the construction quality of composite-foundation and filling compaction degree, it is unnecessary to take equal preloading to avoid excessive embankment settlement caused by the pavement structure.

Reinforcement Technology of Cement Agitation Pile in the Highway Soft Foundation Treatment

2013 ◽  
Vol 329 ◽  
pp. 205-209
Author(s):  
Kai Chen
Keyword(s):  
Soft Soil ◽  
Construction Technology ◽  
Pressing Method ◽  
Treatment Methods ◽  
Deep Mixing ◽  
Replacement Method ◽  
Foundation Treatment ◽  
Soft Foundation ◽  
Mixing Method ◽  
Soil Distribution

There is the soft soil distribution mostly in the regions along the river or the sea in our country, so the soft foundation treatment shold be well done in building highways. With respect to the soft foundation treatment methods, the scholars, engineers and technicians home and abroad have put forward a dozen or more methods, such as replacement method, reinforcement method, top pressing method, sandstone pile method and deep mixing method etc.. This article discusses the reinforcement mechanism, construction technology and some proceedings requiring attention in the construction and detection of the cement agitation pile.

The Effect Analysis of the Thin-Walled Tubular Pile Technology Used in the Foundation Treatment of the High-Filling Railway Freight Yard

2014 ◽  
Vol 919-921 ◽  
pp. 1184-1190
Author(s):  
Jie Yu ◽  
Tian Yue Chu ◽  
Quan Mei Gong
Keyword(s):  
Soft Soil ◽  
Measured Data ◽  
Effect Analysis ◽  
Railway Freight ◽  
Foundation Treatment ◽  
Soft Foundation ◽  
Thin Walled ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Soft Subgrade

On the background of one railway freight yard in Xiao Yong railway , and firstly the use of thin-walled tubular pile is determined in railroad yard through the comparison with other methods in the soft foundation reinforcement. Secondly, the effect of the soft-soil foundation reinforcement combined with the numerical simulation and the measured data is analyzed. Finally, it is defined that the thin-walled tubular piles has good value in the treatment of the high-filling railway yard, and it also can provide a new method for the improvement of the soft subgrade in railway freight yard.

Study on Optimization of Design Parameters for Composite Foundation with Cement-Fly Ash-Gravel Piles

2014 ◽  
Vol 580-583 ◽  
pp. 715-722
Author(s):  
Peng Fei Luo ◽  
Jian Xing Tong ◽  
Xun Hai Sun ◽  
Xin Hui Yang ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Fly Ash ◽  
Soil Layer ◽  
Composite Foundation ◽  
Experimental Result ◽  
Design Parameters ◽  
Pile Spacing ◽  
High Rise ◽  
Pile Diameter ◽  
Permissible Range ◽  
Cushion Layer

Based on theoretical analysis and experimental result, the principle as well as the interaction between pile and soil, the design parameters of composite foundation with cement-fly ash-gravel piles (CFG piles for short) are optimized, which are pile length, pile diameter, pile spacing, pile strength and thickness of cushion layer, in order to put forward the reasonable design parameters for reaching economic and reasonable target. Through the optimized analysis, it is put forward that bearing stratum of pile tip should select a relatively better soil layer, the diameter of CFG pile is usually appropriately to select between 350mm and 500mm, it is usually appropriately to select larger pile spacing under the permissible range between 3d and 5d being ruled by standard, it is appropriately to enlarge the pile diameter to reduce the requirement of pile strength in high rise and super high rise building which requiring bearing capacity of single pile is high, and the thickness of cushion layer is appropriately to select between 0.4 and 0.6 times of the pile diameter.

Numerical Simulation Research on the Settlement Regularity in Pile-Net Composite Foundation

2011 ◽  
Vol 261-263 ◽  
pp. 1251-1256
Author(s):  
Jin Jiang YU ◽  
Qian Gong Cheng ◽  
Cheng Hui Li ◽  
Hua Wen
Keyword(s):  
Numerical Simulation ◽  
Soft Soil ◽  
Composite Foundation ◽  
Simulation Research ◽  
Pile Spacing ◽  
Engineering Characteristics ◽  
Foundation Treatment ◽  
Pile Cap ◽  
Deep Soft Soil

Based on the foundation treatment for deep soft soil in Chaoshan station district, this paper studied the engineering characteristics of soft soil in Chaoshan and the settlement regularity of pile-net composite foundation, etc. by numerical simulation. The results show: the reduction of pile spacing and the settings of pile cap can decrease the settlement of soil among the piles on foundation plane.

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