The Engineering Properties Comparative Study of Wetlands Soft Soil and Soft Soil of other Genesis

2010 ◽  
Vol 150-151 ◽  
pp. 484-492
Author(s):  
Hong Jun Liu ◽  
Wei Shan ◽  
Yan Qiu Yang ◽  
Chun Jiao Wang ◽  
Ying Guo ◽  
...  
Keyword(s):  
Comparative Study ◽  
Soft Soil ◽  
Engineering Properties ◽  
Mechanical Index ◽  
Consolidation Pressure ◽  
Shearing Strength ◽  
Consolidation Coefficient ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Consolidation Degree

In order to provide technical reference in soft soil foundation treatment for construction of high-grade highway in wetlands soft soil area,by collecting undisturbed soil samples in Qiqihaer-Fuyu section of Jiagedaqi-Beijing highway and using triaxial tests, direct shear test, compressed consolidation testing and other testing methods, a detailed laboratory test and study has been carried out on the soft soil engineering properties and the comparative study on physical and mechanical index, compressed consolidation properties, shearing strength and shearing strength index and so on of wetlands soft soil and other genesis soft soil has been carried out,the results showed that: wetlands soft soil is better than delta soft soil in basic physical and mechanical index; comparing shearing strength parameters of wetlands soft soil and lacustrine soft soil shows that: under smaller consolidation degree and the consolidation pressure, their cohesion decreased with the increase of consolidation degree;with the consolidation degree and the consolidation pressure become bigger, the cohesion of wetlands soft soil is higher than lacustrine soft soil, internal friction angle changed little; Comparing with marine soft soil, the primary consolidation coefficient of wetlands soft soil is bigger and the secondary consolidation coefficient is smaller, that shows the foundation of wetlands soft soil is easy to drainage and consolidation. The research results have guiding significances for treatment of wetland soft soil foundation.

scholarly journals Development of an Artificial Intelligence Approach for Prediction of Consolidation Coefficient of Soft Soil: A Sensitivity Analysis

2019 ◽  
Vol 13 (1) ◽  
pp. 178-188 ◽  
Author(s):  
Manh Duc Nguyen ◽  
Binh Thai Pham ◽  
Tran Thi Tuyen ◽  
Hoang Phan Hai Yen ◽  
Indra Prakash ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Soft Soil ◽  
Clay Content ◽  
Liquid Limit ◽  
Soil Parameters ◽  
Consolidation Coefficient ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Intelligence Approach ◽  
Artificial Intelligence Approach

Background: Consolidation coefficient (Cv) is a key parameter to forecast consolidation settlement of soft soil foundation as well as in treatment design of soft soil foundation, especially when drainage consolidation is used in foundation treatment of soft soil. Objective: In this study, the main objective is to predict accurately the consolidation coefficient (Cv) of soft soil using an artificial intelligence approach named Random Forest (RF) method. In addition, we have analyzed the sensitivity of different combinations of factors for prediction of the Cv. Method: A total of 163 soil samples were collected from the construction site in Vietnam. These samples at various depth (m) were analyzed in the laboratory for the determination of clay content (%), moisture content (%), liquid limit (%), plastic limit (%), plasticity index (%), liquidity index (%), and the Cv for generating datasets for modeling. Performance of the models was validated using Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and Correlation Coefficient (R) methods. In the present study, various combinations of soil parameters were applied and eight models were developed using RF algorithm for predicting the Cv of soft soil. Results: Results of model’s study show that performance of the models using different combinations of input factors is much different where R value varies from 0.715 to 0.822. Conclusion: Present study suggested that RF model with appropriate combination of soil properties input factors can help in better and accurate prediction of the Cv of soft soil.

Calculation Method of Bearing Capacity Improvement of Soft Soil Foundation under Vacuum Preloading

2013 ◽  
Vol 353-356 ◽  
pp. 352-356 ◽  
Author(s):  
Yang Shen ◽  
Wen Jun Huang ◽  
Yan De Li ◽  
Hai Dong Xu
Keyword(s):  
Bearing Capacity ◽  
Soft Soil ◽  
Strength Index ◽  
Stress Increment ◽  
Vacuum Preloading ◽  
Capacity Improvement ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Vertical Effective Stress ◽  
Consolidation Degree

The theory of vacuum preloading was mainly focused on calculations of settlement and consolidation degree, but not on the bearing capacity improvement under vacuum preloading. Based on the Mohr-Coulombs failure criterion and elastic-plastic theory, the formula of bearing capacity improvement of vacuum preloading foundation was deduced under undrained condition. The consolidation and vacuum attenuation degree were taken into the consideration, and a calculation formula with fewer parameters by using CU total stress strength index was derived. Meanwhile the relation between bearing capacity and undrained shear strength was presented as well as that of bearing capacity and vertical effective stress increment.

Mechanism and Application on Extra-Long Sand Wells for Deep Soft Foundation Treatment in Highways

2011 ◽  
Vol 250-253 ◽  
pp. 3128-3133
Author(s):  
He Cheng Liang ◽  
Li Jia Chang ◽  
Ai Guo Zhou
Keyword(s):  
Soft Soil ◽  
Monitoring Data ◽  
Dynamic Monitoring ◽  
Foundation Treatment ◽  
Soft Foundation ◽  
Total Settlement ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Consolidation Degree ◽  
Better Than

The soft base in the testing section of Jiang-zhu highwaysis 55 meters deep, and its mechanical property is not better than that of silt soil, the sand-wick drained length is one of the crucial factors for this highwaywhich influences the consolidation speed. Based on the characteristic of soft foundation, experiences and the interrelationship between the processing area and the subjacent bed effecting on draining, the mechanism of extra-long sand-wick for the extra-deep soft foundation is studied. The theoretical consolidation degree in the deep soft foundation treating with extra-long sand-wick drain had been calculated, the designed depth of sand-wick drain were 25 and 22 meters. Moreover, the total settlement will be predicted. According to the monitoring data of displacement and settlement during loading, the characteristic of consolidation settlement of the soft soil foundation had been analyzed. The results indicated that the settlement was very sensitive to the loading speed. The sedimentation became fast with the increasing loading. The sedimentation speed was always very high, which was 15 to 25mm/day on the average. During the prophase of pre-compaction, the consolidation degree of section K53+242.47 (h=25m) was up to 80% in 350 days, which was much faster than the section K53+402.47 (h=22m). Moreover, the soft soil foundation was consolidated stably according to the strict dynamic monitoring data. By using hyperbolic theory to analyze monitoring data, the predictive settlement value of post-project can meet the designed requirement. The treating effect of the 25m depth sand-wick drain was better than that of 22m, which provided available data for extra thick soft foundation treatment.

Research on Soft Soil Foundation Treatment and Relevant Design Technology for Changzhou Section of the Coastal Expressway

2012 ◽  
Vol 204-208 ◽  
pp. 1902-1908
Author(s):  
Huan Sheng Mu
Keyword(s):  
Soft Soil ◽  
Engineering Properties ◽  
Treatment Technology ◽  
Design Technology ◽  
Foundation Treatment ◽  
Depth Analysis ◽  
Soil Foundation ◽  
Soft Soil Foundation

The author of this article gives a detailed description of the basic situation of the coastal expressway, focusing on the characteristics and engineering properties of soft soil as well as a in-depth analysis of the successful soft soil foundation treatment technology using cement mixing pile. This article provides useful reference for engineers facing similar situation.

Research of the Anisotropys Effect on the Deformation and Consolidation Coefficient of the Soft Soil

2013 ◽  
Vol 353-356 ◽  
pp. 374-378
Author(s):  
Hong Jun Liu ◽  
Guo Zhao Quan
Keyword(s):  
Soft Soil ◽  
Soft Ground ◽  
Large Area ◽  
Direction Parallel ◽  
Future Design ◽  
Deposition Surface ◽  
Consolidation Coefficient ◽  
Parallel Direction ◽  
Soil Foundation ◽  
Soft Soil Foundation

The natural soft soil foundations often need to be treated for their difficulty to meet the project requirements. Drainage consolidation method is mainly used in highway projects for large area soft soil foundation treatment, which makes soft ground seepage pathways more complicated. Because of the soft soil anisotropy, the permeability of the different directions of soft ground has certain difference. Based on this, using one-dimensional consolidation test, the effects of anisotropy on the deformation and consolidation coefficient of soft soil are researched through compressing the soft soil with increased pressure time for each stage of load at different depths along the direction perpendicular to deposition surface and direction parallel to deposition surface with the designing multi-level loads. The results show that the compressibility of the soft soil at Jiangmen Binjiang new district has obvious anisotropy, that is, the compression amount along the direction perpendicular to the deposition surface is significantly greater than the amount along the parallel direction. With the increasing consolidation pressure, the variation trend of consolidation coefficient obtained from the compression in the two directions is basically the same, the coefficients of three samples at the different depth along the direction perpendicular to the deposition surface is also greater than the parallel direction, and with the increase of sampling depth the differences of the consolidation coefficient will be more obvious. The research results provide reference for the future design of the soft soil foundation at the region.

Application Research on Composite Foundation of Rammed Soil-Cement Piles Applied in the Da-Guang Expressway from Gu'an to Shenzhou

2013 ◽  
Vol 740 ◽  
pp. 655-658
Author(s):  
Huan Sheng Mu ◽  
Ling Gao
Keyword(s):  
Soft Soil ◽  
Composite Foundation ◽  
Application Research ◽  
Action Mechanism ◽  
Foundation Design ◽  
Soil Cement ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Cement Soil ◽  
Capacity Characteristic

Through the practice of tamped cement soil pile in treatment of soft soil foundation in Guan to Shenzhou section of Daqing-Guangzhou Expressway, the author expounds the action mechanism of rammed soil cement pile, composite foundation design points and calculation method of bearing capacity characteristic value.

Experimental Study of the Rotary Filling Piles with Large-Diameter under the Axial Load

2012 ◽  
Vol 594-597 ◽  
pp. 527-531
Author(s):  
Wan Qing Zhou ◽  
Shun Pei Ouyang
Keyword(s):  
Experimental Study ◽  
Axial Load ◽  
Load Transfer ◽  
Soft Soil ◽  
Large Diameter ◽  
Shaft Resistance ◽  
Tip Resistance ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Deep Soft Soil

Based on the experimental study of rotary filling piles with large diameter subjected to axial load in deep soft soil, the bearing capacity behavior and load transfer mechanism were discussed. Results show that in deep soft soil foundation, the super–long piles behave as end-bearing frictional piles. The exertion of the shaft resistance is not synchronized. The upper layer of soil is exerted prior to the lower part of soil. Meanwhile, the exertion of shaft resistance is prior to the tip resistance. For the different soil and the different depth of the same layer of soil, shaft resistance is different.

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