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.

The Application of Vacuum Preloading Method in Soft Soil Foundation Underwater

2014 ◽  
Vol 580-583 ◽  
pp. 209-212 ◽  
Author(s):  
Yu Qin Feng ◽  
Lu Zhang
Keyword(s):  
Soft Soil ◽  
Effective Means ◽  
Construction Technology ◽  
Strength Index ◽  
Engineering Project ◽  
Vacuum Preloading ◽  
Before And After ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Preloading Method

On the basis of engineering project in coastland, this article analyzes the construction technology and reinforcement mechanism of vacuum preloading reinforces soft soil foundation. By indoor soil test of Reinforcement of soil before and after processing, comparing the change of the physical and shear strength index, verify vacuum preloading method underwater is effective means in handing soft ground and provide some experience for regional development and promotion of underwater application of vacuum preloading technology.

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.

Application of Vacuum Preloading for Soft Foundation Treatment in Grain Storage

2012 ◽  
Vol 190-191 ◽  
pp. 1207-1213
Author(s):  
Qi Xia Liu ◽  
Yang Zhao
Keyword(s):  
Soft Soil ◽  
Construction Method ◽  
Grain Storage ◽  
Vacuum Preloading ◽  
Obvious Effect ◽  
Foundation Construction ◽  
Foundation Treatment ◽  
Soft Foundation ◽  
Soil Foundation ◽  
Soft Soil Foundation

The application of vacuum preloading for soft foundation treatment in grain storage is introduced from its principle，design，construction and the inspections. Its obvious effect is proved by example. The east coast of China is the most developed economical area and major grain and oil manufacturers. Many grain and oil depots have been established. However, in the places where the depots located, soil is soft dirt with low strength grade, high compressibility, small permeability and high possibility of plastic flow, has increased difficulties of grain and oil depots foundation construction. Without enough knowledge of soft soil and lacking of proper foundation construction method and good technology, depots may slip due to foundation’s erosion, and big settlement. If the structure slips, equipments for aeration, dehumidifier, antivirus equipment cannot work well. Based on the statement above, reasonable and effective methods for soft soil foundation work is the key point for construction of high quality and high standard grain and oil depots. This paper mainly discussed when we do depots construction work on the soft soil foundation, exact calculation, construction method and result test of fasten method for the soft foundation under the vacuum circumstance of preloading.

scholarly journals A new calculation method for the bearing capacity of soft soil foundation

2017 ◽  
Vol 9 (10) ◽  
pp. 168781401773252 ◽  
Author(s):  
Fu Zhu ◽  
Wanxi Zhang ◽  
Weizhi Dong ◽  
Mingzhi Sun
Keyword(s):  
Bearing Capacity ◽  
Calculation Method ◽  
Soft Soil ◽  
Soil Foundation ◽  
Soft Soil Foundation

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.

Analysis on Mesoscopic Dynamic of Soft Soil Foundation in the Pearl River Delta Region Based on the Vacuum Preloading Method

2012 ◽  
Vol 594-597 ◽  
pp. 100-104
Author(s):  
Jing Song ◽  
Ren Yi Yue ◽  
Peng Zhang
Keyword(s):  
Pearl River Delta ◽  
Fine Particles ◽  
Soft Soil ◽  
River Delta ◽  
Pearl River ◽  
Pearl River Delta Region ◽  
Delta Region ◽  
Vacuum Preloading ◽  
Soil Foundation ◽  
Soft Soil Foundation

The behavior of particle migration on soft soil foundation in Pearl River Delta region is analyzed considering the mesoscopic dynamic with vacuum preloading method. The numerical predictions are compared with the fine particle data in terms of settlements, horizontal displacements and vacuum degree of horizontal preloading. The repercussions of including the displacements law of fine particles are also studied. It is found that the analysis considering displacements law results in consolidation by rose diagram of particle migration, which is related to the consolidation of the vacuum preloading of soft soil foundation in Pearl River Delta region. It is apparently inconsistent with the vacuum preloading of the drainage which results from the fine particles migration, but it is fully justified by the fact that the real soil consolidation coordinates corrected for rose diagram obtained.

Research on Settlement and Wavy Failure of Road on Very Soft Soil Foundation

2011 ◽  
Vol 261-263 ◽  
pp. 1370-1373
Author(s):  
Shu Wang Yan ◽  
Li Li Zhang ◽  
Li Qiang Sun
Keyword(s):  
High Frequency ◽  
Design Methodology ◽  
Soft Soil ◽  
Heavy Vehicles ◽  
Vacuum Preloading ◽  
Lower Strength ◽  
Existing Problems ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Preloading Method

Soil foundation in Tianjin Harbor is formed by hydraulic filled materials strengthened by vacuum preloading method, which is still with lower strength and larger compressibility. Large settlement and wavy failure of the roads constructed on such soil foundation are often taking place after two or three years of construction, because of the heavy vehicles running on the roads with high frequency. In order to deal with the existing problems of constructing roads on such very soft soil foundation, the following work is carried out: the displacement characteristics of roads constructed on very soft soil foundation are identified; the design methodology of constructing roads is discussed; the settlement of the constructed roads is calculated with FE methods and the mechanism of wavy failure of the roads on very soft soil foundation is analyzed.

Research on Settlement Calculation of Soft Foundation Treated with Vacuum Preloading Based on Stress Path Method

2011 ◽  
Vol 243-249 ◽  
pp. 2864-2868
Author(s):  
Yue Dong Wu ◽  
Shang Chuan Yang ◽  
Han Long Liu
Keyword(s):  
Soft Soil ◽  
Confining Pressure ◽  
Stress Path ◽  
Soil Mass ◽  
Positive Pressure ◽  
Vacuum Preloading ◽  
Surcharge Preloading ◽  
Soft Foundation ◽  
Soil Foundation ◽  
Soft Soil Foundation

Stress state of soft soil foundation under vacuum preloading is completely different from its counterpart under surcharge preloading, and the method of calculating the final settlement of soil mass by means of surcharge preloading (positive pressure) is unreasonable in present design. According to a case of soft foundation stabilized with vacuum preloading and through consolidated-undrained triaxial (CU) test on the specimens sampled in situ, the stress paths under different confining pressure are obtained. The settlement of soft foundation treated with vacuum preloading is calculated by strain isoline method. Compared with the practically measured field data, the errors are analyzed and discussed.

The Applied Research of Underwater Vacuum Preloading Method in Soft Soil Foundation

2014 ◽  
Vol 580-583 ◽  
pp. 742-745
Author(s):  
Yu Qin Feng ◽  
Lu Zhang
Keyword(s):  
Soft Soil ◽  
Soft Ground ◽  
Construction Technology ◽  
Engineering Project ◽  
Vacuum Preloading ◽  
Soft Foundation ◽  
Before And After ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Preloading Method

On the basis of engineering project using underwater vacuum preloading method to strengthening the soft foundation, under the specific geological conditionsthis article analyzes the construction technology and reinforcement mechanism of underwater vacuum preloading of the soft soil foundation. By indoor soil test of Reinforcement of soil before and after processing, compared the change and improve of soil shear strength indexes before and after the reinforcement, it is verified that the underwater vacuum preloading method is a effective mean in handing soft ground, and can be further promoted as a means of handling soft ground along the coastal area of China.

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