scholarly journals Settlement Analysis of Saturated Tailings Dam Treated by CFG Pile Composite Foundation

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Jinxing Lai ◽  
Houquan Liu ◽  
Junling Qiu ◽  
Jianxun Chen
Keyword(s):  
Model Test ◽  
Deformation Modulus ◽  
Composite Foundation ◽  
Laboratory Model ◽  
Tailings Dam ◽  
Foundation Treatment ◽  
Building Foundation ◽  
Cfg Pile Composite Foundation ◽  
Laboratory Model Test ◽  
Cfg Pile

Cement fly ash gravel (CFG) pile composite foundation is an effective and economic foundation treatment approach, which is significant to building foundation, subgrade construction, and so forth. The present paper aims at investigating the settlement behaviors of saturated tailings dam soft ground under CFG pile composite foundation treatment, in which FEM and laboratory model test were utilized. The proposed findings demonstrate that CFG pile treatment is effective in reinforcing saturated tailings dam and loading has little influence on settlement of soil between piles. The variation of soil between piles settlement in FEM has a good agreement with the laboratory model test. Additionally, the cushion deformation modulus has a small effect on the composite foundation settlement, although the cushion thickness will generate certain influence on the settlement distribution of the composite foundation.

scholarly journals Laboratory Model Test to Explore the Bearing Mechanism of Composite Foundation in the Loess Area

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Longfei Xu ◽  
Weijiang Xu ◽  
Aijun Zhang ◽  
Xiaolin Weng ◽  
Gaowen Zhao ◽  
...  
Keyword(s):  
Experimental Data ◽  
Model Test ◽  
Load Test ◽  
Composite Foundation ◽  
Tangent Modulus ◽  
Laboratory Model ◽  
Single Pile ◽  
Loess Area ◽  
Modulus Method ◽  
Laboratory Model Test

Pile composite foundation can make good use of the bearing capacity of the soil and pile, which is widely used in the Chinese northwest loess area. However, the theory of pile composite foundation is far from sufficient, hindering its long-term development. Aiming at this problem, a laboratory model test of pile composite foundation in the loess area was conducted to explore the common working mechanism and variations of each bearing stage. Besides, the settlement of the single pile composite foundation was calculated by using the modified tangent modulus method, and the result was compared with the experimental data. The main results of this paper are as follows: Both in the single pile and single pile composite foundation, loading-settlement curves showed a trend of “elastic to elastoplastic to plastic,” accompanied by the appearance of plummeting point. Influenced by the pile group effect, the loading-settlement curve of the group pile composite foundation showed a slow-varying trend without an obvious breakdown point. Pile axis stress increased with the growth of upper load. At the beginning of loading, the pile axis stress indicated such a distribution that stress on both ends of the pile was larger than that in the middle of the pile. When reaching a certain load, the location of the biggest pile axis stress transferred to the pile top, and the pile axis stress decreased gradually as the pile became deep. The side friction resistance in the static load test of the single pile was always positive, whereas in the composite foundation of a single pile and a group of piles, negative side resistance appeared in the upper side of the neutral point. Pile-soil stress ratio in the depth of 12 cm changed with the upper load. The outcome calculated by the modified tangent modulus method had a relatively better consistency with experimental data if the upper load was not too large.

scholarly journals Stress Analysis of CFG Pile Composite Foundation in Consolidating Saturated Mine Tailings Dam

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Jinxing Lai ◽  
Houquan Liu ◽  
Junling Qiu ◽  
Haobo Fan ◽  
Qian Zhang ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Mine Tailings ◽  
Stress Ratio ◽  
Deformation Modulus ◽  
Earth Pressure ◽  
Composite Foundation ◽  
Three Dimensions ◽  
Laboratory Model ◽  
Soil Stress ◽  
Cfg Pile

Cement fly-ash gravel (CFG) pile is a widely used ground reinforcement technique. This paper aims to address the mechanical characteristics of CFG composite foundation in consolidating saturated mine tailings (MTs) dam. The field static load tests were employed to explore the bearing capacity of the CFG composite foundation, and finite element (FE) models in three dimensions validated through comparison with experimental results were used to discuss the pile-soil stress distribution and pile-soil stress ratio of the CFG composite foundation. The results indicate that the distribution of earth pressure and pile stress is relatively homogeneous and stable over depth and load, while the development of CFG composite foundation bearing capacity is insufficient, in which the developed bearing capacity of CFG piles is less than 50% of its characteristic value. Additionally, compared with the laboratory model test results, the pile-soil stress ratio decreases with the increasing of the load in FEM results proved to better conform to the actual engineering conditions. Furthermore, the deformation modulus and thickness of cushion exert significant influence on pile-soil stress ratio and integral bearing capacity of CFG composite foundation.

Temperature analysis of CFG pile composite foundation in high latitudes and low altitude island permafrost

2019 ◽  
Vol 10 (1) ◽  
pp. 85-101 ◽  
Author(s):  
Jinliang Liu ◽  
Yanmin Jia
Keyword(s):  
Temperature Variation ◽  
Atmospheric Temperature ◽  
Composite Foundation ◽  
Maximum Temperature ◽  
Temperature Cycle ◽  
Content Type ◽  
Foundation Treatment ◽  
Low Altitude ◽  
Cfg Pile Composite Foundation ◽  
Cfg Pile

Purpose Cement fly ash gravel (CFG) pile composite foundation is an effective and economic foundation treatment approach, which is significant to build foundation, subgrade construction, and so forth. The purpose of this paper is to present a research on the temperature behaviours of high-latitude and low-altitude island permafrost under CFG pile composite foundation treatment. Design/methodology/approach In the process of CFG pile construction, the temperature of permafrost and pile body was monitored using the temperature sensors. The influence of subgrade height and atmospheric temperature cycle on permafrost temperature was analysed by finite element simulation. Findings In the process of CFG pile construction, the change curve of pile temperature and the temperature of permafrost beside pile following time can be divided into six stages, and the duration of these stages is at least one month. The temperature variation of permafrost while constructing subgrade in FEM has a good agreement with the results of field temperature monitoring. The height of subgrade not only affects the maximum temperature increase of permafrost and the re-frozen time of permafrost after the construction of CFG pile composite foundation, but also affects the temperature variation amplitude of permafrost during atmospheric temperature cycle. Originality/value The research will provide a reference for the design on the CFG pile composite foundation used for island permafrost and guarantee the stability of the structure; thus, it has an important significance.

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.

Laboratory Model Test of EPB Shield Tunneling in a Cobble-Rich Soil

2020 ◽  
Vol 146 (10) ◽  
pp. 04020112 ◽  
Author(s):  
Xiongyu Hu ◽  
Chuan He ◽  
Gabriel Walton ◽  
Yong Fang ◽  
Guanghui Dai
Keyword(s):  
Model Test ◽  
Laboratory Model ◽  
Shield Tunneling ◽  
Laboratory Model Test ◽  
Epb Shield
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