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 of Road on Very Soft Soil Foundation

2012 ◽  
Vol 433-440 ◽  
pp. 207-214
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.

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 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.

Study of “Wave Type” Uneven Settlement and Reinforcing Method of Soft Clay Foundation

2011 ◽  
Vol 243-249 ◽  
pp. 2990-2996
Author(s):  
Li Qiang Sun ◽  
Shu Wang Yan ◽  
Hong Juan He ◽  
Yu Xu
Keyword(s):  
Soft Soil ◽  
Soft Clay ◽  
Traffic Load ◽  
Dominant Factor ◽  
Wave Type ◽  
The Road ◽  
Soil Foundation ◽  
Soft Soil Foundation ◽  
Preloading Method

The deformation is the dominant factor of the quality of the road constructed on the soft soil foundation. Tianjin DongJiang port is located on the hydraulic filled soil foundation which is improved by using vacuum preloading method. Roads in this area often suffer wave type asymmetry settlement, which serious affects the usage of the road and causes damage to both vehicles and human being. It is found that the initial wave asymmetry deformation of the road on very soft soil foundation usually exists and will be developing continuously under the traffic load. The mechanism of the wavy failure of the road is discussed by establishing a mechanical model. The method of using geogrids to reduce the asymmetry deformation is proposed, the reinforce effect is analyzed using finite element method.

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.

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.

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 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.

scholarly journals Estimation of Influence Scope of Lateral Displacement of Soft Ground under Vacuum Pressure with PVD

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Jingyun Liu ◽  
Hongtao Fu ◽  
Jun Wang ◽  
Yuanqiang Cai ◽  
Xiuqing Hu
Keyword(s):  
Clayey Soil ◽  
Lateral Displacement ◽  
Soft Soil ◽  
Ground Surface ◽  
Vacuum Pressure ◽  
Vacuum Preloading ◽  
Treated Area ◽  
Prefabricated Vertical Drain ◽  
Soil Foundation ◽  
Soft Soil Foundation

The application of vacuum pressure to a treated area not only induces vertical settlement and inward lateral displacement but also causes the formation of tension cracks near the ground surface. In general, the strain method is applied to calculate the lateral displacement at the boundary of a treated area; however, the influence scope of lateral displacement has not yet been presented. Based on the in situ data of soft clayey soil foundation treated by vacuum consolidation, lateral displacement was estimated in the influence scope in this study. To calculate the influence scope of lateral displacement induced by vacuum pressure, the ratio of the lateral displacement within the influence scope to the ground surface settlement under the centre of the treated area is defined as the maximum value of the lateral displacement (ELD) within the influence scope. This paper proposes a direct relationship between ELD and the distance from the treated area boundary (Lx), considering the length of the prefabricated vertical drain. In addition, the FEA (finite-element analysis) is used to simulate the process of vacuum preloading to reinforce soft soil foundation. The influence scope simulated is almost close to the calculated value Lx. Accordingly, the safety distance between the boundary of the treated area and the surrounding building can be estimated when the soft soil foundation is consolidated by using a vacuum preloading method.

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