Study on the Effect of Jet Grouting Pile Reinforcing Soft Soil Subgrade

2012 ◽  
Vol 594-597 ◽  
pp. 1420-1428 ◽  
Author(s):  
Gang Yu Liu ◽  
Bing Long Wang
Keyword(s):  
High Speed ◽  
Soft Soil ◽  
Ground Surface ◽  
Horizontal Displacement ◽  
Composite Foundation ◽  
Original Design ◽  
Obvious Effect ◽  
High Speed Railway ◽  
Jet Grouting ◽  
Ground Surface Settlement

Composite foundation is commonly used to control the soft soil subgrade settlement. Considering that post-construction settlement of high speed railway is strictly controlled, it’s supposed to use jet grouting pile to strengthen the existed composite foundation and it’s necessary to analyse the effectiveness. Take a line as an example, analyse embankment settlement regularity of the original design mixing pile reinforcement and jet grouting pile reinforcement, evaluate the effect of the jet grouting pile reinforcement. The results show that the jet grouting pile reinforcement on the basis of original design does not have obvious effect on the embankment surface and ground surface settlement control, but effectively controls horizontal displacement at toe of slope and improves the foundation stability.

The Dynamic Analysis of Soft Soil Subgrade in High-Speed Railway Strengthened by PHC Pile

2014 ◽  
Vol 1030-1032 ◽  
pp. 908-911 ◽  
Author(s):  
Zhen Hua Pan ◽  
Kong Ming Yan ◽  
Jin Biao Wu ◽  
Zhe Wang ◽  
Wei Ming Liao
Keyword(s):  
Prestressed Concrete ◽  
High Speed ◽  
Dynamic Stress ◽  
Soft Soil ◽  
Time History ◽  
Composite Foundation ◽  
High Speed Train ◽  
High Speed Railway ◽  
Soft Soil Area ◽  
Soil Area

The combination of PHC pile (prestressed concrete pile) with geogrid to reinforce the foundation has been widely used in high-speed railway, and the response of dynamic stress under the high-speed train is worth studying. By using Midas/GTS NX software to establish a 3-D model of pile-net composite foundation in one section of Hangzhou - Shenzhen line, the influence of pile-net composite foundation generated by high-speed train is studied. Moreover, this paper also studies the distribution and propagation of dynamic stress generated by train load in soft soil area. The results show that the dynamic stress reducing quickly in the embankment structure and the time –history curve of the dynamic stress behaves differently along the depth. With the depth increasing, there is phenomenon of peak superposition in the time-history curve of the vertical dynamic stress. In the meanwhile, the PHC pile is the main structure to propagate and sustain the dynamic stress in soft soil area, and with the tendency of ‘large in the middle, small on both ends’.

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.

scholarly journals Displacement Characteristics of Shallow-Buried Large-Section Loess Tunnel with Different Types of Pre-Supports: A Case Study of New Badaling Tunnel

2019 ◽  
Vol 10 (1) ◽  
pp. 195 ◽  
Author(s):  
Daoping Liu ◽  
Dingli Zhang ◽  
Qian Fang ◽  
Zhenyu Sun ◽  
Liqiang Cao ◽  
...  
Keyword(s):  
Cross Sections ◽  
High Speed ◽  
Ground Surface ◽  
In Situ Tests ◽  
Large Section ◽  
High Speed Railway ◽  
Excavation Process ◽  
Ground Surface Settlement ◽  
The Face

Three-bench seven-step excavation method (TSEM) has been widely used in large-section loess tunnels for high-speed railway in China. As the most commonly applied pre-supports, pipe roofs and leading ductules are broadly used in the ground reinforcement of loess tunnels. Their application is to ensure face stability and prevent tunnel collapse during construction. This study focused on the impacts of the TSEM on the ground surface settlement (GSS), as well as the tunnel displacement characteristics for the high-speed railway tunnels with large cross-sections in loess ground. Furthermore, the reinforcement effects of the two kinds of pre-supports were compared in this study. In-situ tests for a total of 12 sections were conducted to reveal the GSSs and displacement characteristics for the shallow-buried large-section loess tunnels. The monitoring results showed that the excavation process plays a significant role on the GSSs and tunnel displacements. A maximum value was observed for the tunnel displacement rate at the excavation of the upper and middle benches, where the face instability or collapse were prone to occur. The GSS trough curves were deviated to the early excavation side, with no conformation to the Gauss distribution. After a series of comparisons, we concluded that the pre-reinforcement effect of the pipe roof is better than that of the leading ductule for the loess tunnels.

scholarly journals Deformation Characteristics of Raising, Widening of Old Roadway on Soft Soil Foundation

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2117
Author(s):  
Keke Li ◽  
Wenyuan Xu ◽  
Liang Yang
Keyword(s):  
Lateral Displacement ◽  
Soft Soil ◽  
Ground Surface ◽  
Surface Settlement ◽  
Deformation Characteristics ◽  
Construction Methods ◽  
Ground Surface Settlement ◽  
Total Settlement ◽  
Soil Foundation ◽  
Soft Soil Foundation

The deformation characteristics of a raised and widened old Chinese roadway on a soft soil foundation are investigated in this study via finite element numerical simulation. The rules of ground surface settlement, slope foot lateral displacement, and ground surface settlement evolution of the roadbed under three modes (one-time construction of an eight-lane expressway, widened four-lane expressway, and raised/widened four-lane expressway) are compared. The ground surface settlement process of the eight-lane road foundation, which is formed by first widening and then raising the road, is highly complex. The ground surface settlement curve under the old road foundation increases and then decreases. The lateral displacement of the slope foot also interacts with the widening and raising of the eight-lane roadbed foundation. The range of lateral displacement is 70.05, 42.58, 124.81, 104.54 mm. Fifteen years after construction, the total settlement of the raised and widened roadbed is much larger than that of the one built directly. The total settlement values at the center of the two roadbeds are 297.05 and 234.85 mm, respectively. This manuscript provides data support for the reconstruction and expansion of roads on soft soil foundations, for choosing appropriate construction methods to build roads, and for avoiding major road damage, which is of great significance to the construction of road infrastructure in the future.

scholarly journals Review of research on high-speed railway subgrade settlement in soft soil area

2020 ◽  
Vol 28 (2) ◽  
pp. 129-145 ◽  
Author(s):  
Shunhua Zhou ◽  
Binglong Wang ◽  
Yao Shan
Keyword(s):  
High Speed ◽  
Soft Soil ◽  
High Speed Railway ◽  
Soft Soil Area ◽  
Soil Area

scholarly journals Vertical and Lateral Bearing Capacity of FRP Composite Sheet Piles in Soft Soil

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Zhe Wang ◽  
Shuwei Wu ◽  
Kaiwen Weng ◽  
Wangjing Yao ◽  
Sifa Xu ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Horizontal Displacement ◽  
Yangtze River Delta ◽  
Composite Foundation ◽  
Sheet Pile ◽  
Composite Sheet ◽  
Frp Composite ◽  
Vertical Bearing ◽  
Full Scale Tests

Fiber-reinforced polymer (FRP) composite sheet piles are usually favored for slope and river-retaining structures due to their construction and environmental efficiency. Their applications, however, have been hindered by the lack of understanding of the bearing capacity. This paper studies the vertical and lateral bearing capacity of FRP composite sheet piles through three full-scale tests conducted in Haiyan, a soft soil site in the Yangtze River Delta of China. In the three tests, we measured the vertical bearing capacity of the FRP composite sheet piles, the bearing capacity of the composite foundation, and the lateral capacity of the FRP composite sheet piles, respectively. The test results show that the Q-S (load on the top of the pile versus settlement) curve of the FRP composite sheet piles exhibits a steep fall while that of the composite foundation is relatively flat. Moreover, the ultimate bearing capacity of the FRP composite sheet piles is measured to reach 23.8 kN while that of the composite foundation increases by 47.1 %, reaching 35.0 kN. It shows that the FRP composite sheet piles under the composite foundation have a favorable bearing performance. Finally, the final horizontal displacement of the FRP composite sheet pile in the reinforced area with anchoring the sheet pile is smaller than the final horizontal displacement in the nonreinforced area, indicating that the horizontal bearing capacity can be significantly improved by anchoring the sheet pile.

scholarly journals Research on character of screw pile group composite foundation used in high-speed railway

2019 ◽  
Vol 265 ◽  
pp. 05010
Author(s):  
Maocai Zhao ◽  
Lu Zhang
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Pile Group ◽  
Element Model ◽  
Composite Foundation ◽  
Design Parameters ◽  
High Speed Railway ◽  
Screw Pile ◽  
Side Resistance ◽  
Pile Length

As a result of rapid development of a high-speed railway and infrastructure in China in recent years, the subgrade deformation and settlement control standards put forward more stringent requirements. Based on ABAQUS 6.14, established finite element model of screw pile group composite foundation. Then obtained the settlement, axial force distribution and pile side resistance distribution of center pile of pile group. Next design parameters sensitive analysis was made, such as pile length, pile spacing and so on, in order to obtain a reasonable design pile parameters by analysis of mechanical behavior.

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.

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