Ground Improvement and Evaluation Technology of Bearing Capacity under Highway Embankment in Collapsible Loess Area

2012 ◽  
Author(s):  
Yilin Liu ◽  
Kaihua Xu
Keyword(s):  
Bearing Capacity ◽  
Ground Improvement ◽  
Loess Area ◽  
Collapsible Loess ◽  
Highway Embankment

scholarly journals Application of Controllable Splitting Grouting Technology in Loess Foundation Reinforcement

2021 ◽  
Vol 2101 (1) ◽  
pp. 012025
Author(s):  
Qingang Liu ◽  
Mingru Zhou ◽  
Lin Zhong ◽  
Shaofei Li ◽  
Yiming Chen
Keyword(s):  
Bearing Capacity ◽  
Foundation Settlement ◽  
Loess Area ◽  
Grouting Pressure ◽  
Collapsible Loess ◽  
Pressure Grouting ◽  
Jack Up ◽  
Heating Boiler ◽  
Large Heating

Abstract Taking the foundation settlement accident of a large heating boiler foundation in a city in collapsible loess area as an example, controllable splitting grouting can be achieved by controlling the grouting pressure, grouting pipe opening form, grouting volume and grouting method etc., so as to stabilize foundation settlement and improve foundation bearing capacity, for the boiler with large uneven settlement, for boilers with large uneven settlement, quicklime piles are used to jack up the foundation after splitting grouting to stabilize the foundation, the foundation is lifted with quicklime piles after splitting grouting to stabilize the foundation. The results show that the grouting amount of soil is within the design range, the grout splits in the soil several times to form a slurry vein, the settlement is stable after boiler reinforcement, the quicklime method can jack up the foundation and reduce the uneven settlement of the foundation, and the use of controllable splitting grouting can basically eliminate the slight collapsibility grade loess, which provides a new idea for solving the similar problem of uneven settlement of collapsible loess foundation buildings.

Application of Lime Soil Pile in Collapsible Loess Ground Treatment

2014 ◽  
Vol 1049-1050 ◽  
pp. 256-259 ◽  
Author(s):  
Pei Chen ◽  
Qiang Cui
Keyword(s):  
Bearing Capacity ◽  
Loess Area ◽  
Ground Treatment ◽  
Collapsible Loess ◽  
Practical Engineering ◽  
Natural Foundation ◽  
Technology Foundation ◽  
Design Construction

When the bearing capacity of natural foundation cannot meet load requirements, generally the ground treatment usually can be taken to strengthen it. In this paper, from the practical engineering, the design, construction, and detection of the lime soil pile were introduced. The results show that the lime soil pile in collapsible loess area reinforcement technology foundation is feasible. The bearing capacity and stability of the treated foundation can meet the requirements.

Bearing capacity of spread footings on aggregate pier–reinforced clay: updates and stress concentration

2020 ◽  
Vol 57 (5) ◽  
pp. 717-727 ◽  
Author(s):  
Taeho Bong ◽  
Armin W. Stuedlein ◽  
John Martin ◽  
Byoung-Il Kim
Keyword(s):  
Stress Concentration ◽  
Bearing Capacity ◽  
Cross Validation ◽  
Slenderness Ratio ◽  
Ground Improvement ◽  
Analytical Models ◽  
Loading Test ◽  
Replacement Ratio ◽  
Area Replacement Ratio ◽  
Reinforced Clay

Aggregate piers represent an economical ground improvement technique used to increase bearing capacity and reduce settlements of weak soils. Several approaches have been developed to estimate the bearing capacity of aggregate pier–reinforced clay, but these models exhibit large prediction bias and uncertainty. This study uses newly developed footing loading test data to investigate the relationship between the bearing capacity and the area replacement and slenderness ratios. The bearing capacity of a single aggregate pier, whether isolated or in groups, below a loaded footing increases as the area replacement ratio decreases due to increase in extent of confined soil surrounding the pier. The length and diameter of an aggregate pier is also shown to result in significantly increased bearing capacity, an effect that diminishes with increasing slenderness. New modifications are proposed to existing simplified and cavity expansion models to account for the effect of confinement, area replacement ratio, and slenderness ratio using a leave-one-out cross-validation technique. The cross-validation analysis resulted in robust bearing capacity models that are more accurate than existing analytical models. Additionally, the stress concentration ratio for shallow foundations supported by aggregate pier–reinforced plastic soils at failure was estimated and compared with the available data, indicating its sensitivity to design variables and showing that this critical design parameter may be predicted using the updated models.

Application Research of Compaction Pile in Heavy Collapsible Loess

2011 ◽  
Vol 90-93 ◽  
pp. 1390-1393 ◽  
Author(s):  
Yong Qiang He ◽  
Yan Peng Zhu ◽  
Yun Wu ◽  
Xiao Qing Wang
Keyword(s):  
Soil Compaction ◽  
Composite Foundation ◽  
Application Research ◽  
Loess Area ◽  
Foundation Treatment ◽  
Collapsible Loess ◽  
Expansion Theory ◽  
Soil Compressibility ◽  
Cavity Expansion Theory ◽  
Physical Mechanics

Compaction piles is one of the conventional methods for foundation treatment in collapsible loess, there are very few research results about soil compaction effect between piles when forming the piles. Firstly, the stress field and displacement field of soil around compaction piles are elastic-plastic analyzed on the basis of the cavity expansion theory; then a series of field and laboratory tests were performed to evaluate the treatment effect of the compaction pile composite foundation. The result shows that the collapsibility has been eliminated, all physical mechanics indexes have been improved, and soil compressibility and modulus of compressibility are also increased remarkably. It embodies the correctness of the computation theory. And the feasibility of the compaction piles composite foundation on collapsible loess area is further proved.

scholarly journals APPLICATION THE POINT FOUNDATION (PF) METHOD FOR SOFT SOIL IMPROVEMENT: A CASE STUDY FROM VETNAM

2020 ◽  
Vol 53 (2D) ◽  
pp. 1-18
Author(s):  
Bui Truong Son
Keyword(s):  
Bearing Capacity ◽  
Ground Improvement ◽  
Soft Soil ◽  
Soil Improvement ◽  
Static Compression ◽  
Successful Case ◽  
Soft Ground Improvement ◽  
Final Settlement ◽  
Shallow Footing

The point foundation method is the head enlarged cement deep mixing columns with high-quality control which can be used for soft ground improvement. The article aims to present the application of this method to treat soft soil for the foundation of Samse Vina factory, Ninh Binh province. The thickness of soft soil varies from 5.4 m to 7.4 m with high compressibility and low shear strength. Thus, point foundation was used to improve this layer. The prediction methods of soil bearing capacity and the settlement on the point foundation were calculated. After the treatment of soil, the unconfined compression strength of the point foundation column was determined and the static compression test for the point foundation column was also performed. The research results show that this method can significantly reduce the settlement of shallow footing and improved the bearing capacity of the soil. The final settlement of shallow footing was smaller than 2.54 cm and the bearing capacity of soil treatment can be satisfied with the requirement of construction building. This is a successful case of the application of point foundation to improve soft soil in Vietnam.

scholarly journals Analysis of Vertical Load Transfer Mechanism of Assembled Lattice Diaphragm Wall in Collapsible Loess Area

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mingtan Xia ◽  
Xudong Zhang ◽  
Gengshe Yang ◽  
Liu Hui ◽  
Wanjun Ye
Keyword(s):  
Failure Modes ◽  
Load Transfer ◽  
Diaphragm Wall ◽  
Vertical Load ◽  
Soil System ◽  
Loess Area ◽  
Collapsible Loess ◽  
Negative Friction ◽  
Vertical Bearing ◽  
Soil Interface

Based on analysis of the formation mechanism and characteristics of the negative friction in collapsible loess areas, this study investigates the load transfer law of a wall-soil system under a vertical load, establishes the vertical bearing model of a lattice diaphragm wall, and analyzes the vertical bearing capacity of an assembled latticed diaphragm wall (ALDW) in a loess area. The factors influencing the vertical bearing characteristics of the ALDW in a loess area are analyzed. The vertical bearing mechanism of the lattice diaphragm wall in the loess area is investigated. The failure modes of the ALDW in the loess area are mainly shear failure of the soil around the wall and failure of the wall-soil interface. In the generation and development of negative friction, there is always a point where the relative displacement of the wall-soil interface is zero at a certain depth below the ground; at this point, the wall and soil are relative to each other. The collapsibility of loess, settlement of the wall and surrounding soil, and rate and method of immersion are the factors affecting the lattice diaphragm wall. The conclusions of this study provide a reference for the design and construction of ALDWs in loess areas.

Analysis of Foundation Non-Uniform Settlement for Building on Collapsible Loess

2013 ◽  
Vol 353-356 ◽  
pp. 213-216 ◽  
Author(s):  
Yuan Xun Li ◽  
Yan Peng Zhu ◽  
Shuai Hua Ye ◽  
Zhong Mao He
Keyword(s):  
Water Level ◽  
Underground Water ◽  
Frost Heaving ◽  
Loess Area ◽  
Adjacent Buildings ◽  
Project Analysis ◽  
Collapsible Loess ◽  
Underground Water Level

The primary causes of non-uniform settlement for buildings on collapsible loess are large settlement of subsoil, local subsidence foundation, frost heaving of ground, infusion foundation, underground water level decrease and the influence of adjacent buildings and so on. According to the characteristics of the project, analysis the reasons of building that non-uniform settlement and fissure on the wall. Combine the method of reinforce the rectification for original building, put forward the method of reinforce the rectification which is applicable to the project. And put forward some suggestions for collapsible loess area construction, for the colleague reference.

scholarly journals A Full-Scale Field Study on Bearing Characteristics of Cast-in-Place Piles with Different Hole-Forming Methods in Loess Area

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Zhijun Zhou ◽  
Tao Yang ◽  
Haobo Fan
Keyword(s):  
Bearing Capacity ◽  
Field Study ◽  
Load Transfer ◽  
Full Scale ◽  
Rotary Drilling ◽  
Loess Area ◽  
Side Resistance ◽  
Attenuation Rate ◽  
Scale Field ◽  
Forming Methods

This paper presents the results from a full-scale field study on the 3 different types of cast-in-place piles: rotary drilling piles (RDPs), manual digging piles (MDPs), and impact drilling piles (IDPs), for a bridge construction project of Wuqi–Dingbian Expressway, in Shaanxi. The results indicate that under the similar conditions, MDP exhibits the largest bearing capacity (11000 kN) in the loess area, followed by RDP (9000 kN) and IDP (8000 kN). And all tested values exceed the estimated value (7797.9 KN), indicating that the calculation formula of bearing capacity recommended by the Chinese standard is safe and conservative. During the load transfer process, the axial force attenuation rate of the pile body increases with pile side resistance. The average attenuation rate of MDP is the largest (24.2%), followed by RDP (19.72%) and IDP (16.69%). The bearing characteristics of these test piles are mainly pile side resistance, but the manual digging method created the least amount of disturbance to the soil around the pile, and due to its hole wall being rough, this enhances the pile-soil interactions. Hole-forming methods mainly affect the exertion of pile side resistance compared with pile end resistance. In view of pile side resistance and pile end resistance not taking effect at the same time, degree of exertion of these 2 resistances should be considered when designing cast-in-place piles in loess areas, and different partial coefficients should be used.

Sign in / Sign up

Export Citation Format

Share Document