scholarly journals The potential of using fine rock for replacing soft soil in construction of a breakwater at Chan May port

2020 ◽  
Vol 61 (4) ◽  
pp. 75-85
Author(s):  
Nu Thi Nguyen ◽  
Son Truong Bui ◽  
Dung Tien Le ◽  
Keyword(s):  
Sea Level ◽  
Soft Soil ◽  
Soil Layer ◽  
Soft Ground ◽  
Ground Treatment

Breakwater is an important construction in Chan May port. The construction of breakwaters faces many difficulties due to the soft soil layer with a thickness of more than ten meters and located under the sea level. Breakwater is unstable as well as high of settlement. Therefore, the soft soil under the breakwater was replaced by fine rock. The results show that it is feasible to replace soft soil by fine rock when constructing breakwater in the sea. This is the basis for the design of soft ground treatment for breakwaters in Vietnam.

The Responses of Soft Ground Materials Subjected to Dynamic Loading

2012 ◽  
Vol 591-593 ◽  
pp. 977-981
Author(s):  
Jun He ◽  
Bing Bai ◽  
Quan Fei Chen
Keyword(s):  
Pore Pressure ◽  
Dynamic Loading ◽  
Soft Soil ◽  
Soil Layer ◽  
Ground Surface ◽  
Vertical Displacement ◽  
Dynamic Compaction ◽  
Soft Ground ◽  
Soil Foundation ◽  
Soft Soil Foundation

The responses of saturated soft soil foundation under dynamic loading are analyzed using numerical method. The distributions of pore pressure in space are given, and the variations of pore pressure with time are also discussed. Besides, the distributions of vertical stresses and vertical displacement are also given. Studies show that during the period of dynamic loading, the pore pressure and stress in soil layer grows very fast, and also decreases rapidly in the unloading phase. With the increase of dynamic compaction time, the locations of the maximum values gradually move down. Moreover, the pore pressure and stress gradually decreases with the increase of the distance away from hammer point. On the other hand, the tamping pit in ground surface under dynamic loading has a larger settlement, and furthermore decreases with the increase of depth.

scholarly journals Applying the Equivalent Plane Strain solution to design the soft soil improvement by vertical drains

2020 ◽  
Vol 61 (3) ◽  
pp. 28-37
Author(s):  
Nu Thi Nguyen ◽  
Keyword(s):  
Plane Strain ◽  
Permeability Coefficient ◽  
Soft Soil ◽  
Soil Improvement ◽  
Field Monitoring ◽  
Soft Ground ◽  
Vertical Drains ◽  
Equivalent Permeability ◽  
Ground Treatment ◽  
Treatment Design

The soft soil improvement by vertical drains (PVD, sand drains) are widely used in Vietnam. One of the methods is used for designing soft soil improvement by vertical drains is the Equivalent Plane Strain solution. To use this solution, the permeability coefficient of soil is converted into the equivalent permeability under plane strain. The paper presents the application of this solution to design soft soil improvement by sand drains at Km 3+130 Vi Thanh - Can Tho. It indicated that the settlement results of the soft ground treatment design based on Equivalent Plane Strain solution are similar to those from the Axisymmetric Condition analysis and field monitoring.

Research to build technological procedure for soft ground improvement using sea sand-cement-fly ash column

2020 ◽  
Vol 61 (HTCS6) ◽  
pp. 1-9
Author(s):  
Thinh Duc Ta ◽  
Phuc Dinh Hoang ◽  
Thang Anh Bui ◽  
Trang Huong Thi Ngo ◽  
Diu Thi Nguyen ◽  
...  
Keyword(s):  
Fly Ash ◽  
Load Capacity ◽  
Ground Improvement ◽  
Soft Soil ◽  
Soil Reinforcement ◽  
Soft Ground ◽  
Design Calculation ◽  
Sea Sand ◽  
Composite Ground ◽  
Soft Ground Improvement

Sea sand-cement-fly ash column technology for soft soil treatment is a new technology in the process of completing the theoretical basis, the experimental basis, and the construction of the ground treatment technological procedure. The paper presents the results of scientific research on design, calculation, construction, and acceptance of sea sand-cement-fly ash column. The scientific basis for the design of column is to consider the role of the column in composite ground, that is to use the column as soft ground improvement or soft soil reinforcement. The important parameters for the column design are: cement and fly ash content; column length; column diameter; number of columns; distance among columns; load capacity and settlement of composite ground. The sequence of steps of construction and acceptance of column includes: selection of construction equipment, preparation of construction sites, trial construction, official construction, evaluation of ground quality after treatment and preparation of document for acceptance.

scholarly journals CONCERNING THE EXTRACTION OF A SLACK SOIL LAYER FROM COMPRESSIBLE THICKNESS OF FOUNDATION STRATUM OF FINITE WIDTH FOUNDATIONS

2019 ◽  
Vol 7 (4) ◽  
pp. 49-56
Author(s):  
Zaven Ter-Martirosyan ◽  
Armen Ter-martirosyan ◽  
Valery DEMYANENKO
Keyword(s):  
Analytical Solutions ◽  
Soft Soil ◽  
Soil Layer ◽  
Horizontal Displacement ◽  
Creep Model ◽  
Shear Stresses ◽  
Finite Width ◽  
Relative Depth ◽  
Weak Layer ◽  
Horizontal Displacements

The paper provides a quantitative assessment of the deflected mode of foundation stratum of finite width foundation, in the compressible thickness of which there is a slack clay soil layer. A number of criteria for assessing the possibility or impossibility of extruding a slack layer depending on its strength and rheological properties, as well as the relative thickness of the layer to its length (h/l) and the relative depth of the layer (h/d) have been given. Closed analytical solutions are given to determine the rate of Foundation precipitation depending on the rate of extrusion of the weak layer, including taking into account the damped and undamped creep. The analytical solutions in the article are supported by the graphical part made with the help of the Mathcad program. Plots of changes in shear stresses in the layer along the x axis at different distances from the axis and at different values 0, contours of horizontal displacement velocities in the weak layer at different distances from the x axis, plots of horizontal displacement velocities in the middle of the weak layer and plots of horizontal displacement velocities in the weak layer at different distances from the x axis are given. As a calculation model for describing the creep of a slack layer, rheological ones of the soil using power and hyperbolic functions and their modifications have been considered. In addition, most modern rheological models that take into account soil hardening during creep have been considered. Based on these models, the problem is solved by means analytical and numerical methods using the Mathcad PC and the PLAXIS PC according to the Soft Soil Creep model. The graphical part shows the isofields of horizontal displacements for 300 days and 600 days and the corresponding contours of horizontal displacements.

scholarly journals Experimental application of optimal depth of PVDs determination under vacuum loading condition

2016 ◽  
Vol 19 (1) ◽  
pp. 116-121
Author(s):  
Nhat Dai Vo ◽  
Viet Hoang Quoc Lam ◽  
Tuan Minh Pham
Keyword(s):  
Loading Condition ◽  
Ground Improvement ◽  
Soft Soil ◽  
Small Error ◽  
Soft Ground ◽  
Optimal Depth ◽  
Geological Feature ◽  
Experimental Application ◽  
Technical Requirements ◽  
Soft Ground Improvement

Viet Nam is one of the country that has a very soft and complicated geological feature. Therefore, how to economize cost but satisfy the standard and technical requirements in designing by selecting an appropriate method in building especially projects constructed on soft ground is always needed to consider and research continuouslly. In this paper, a method how to determine the optimal depth of PVDs under vacuum loading condition for soft ground improvement is presented and applied to specific case in 861 provincial street, Ward Cai Be, Tien Giang District. The soft soil includes two layers with total 12m thick and is allowed to drain on the top and bottom faces (double drainage). The result shows that the optimal depth of PVDs is about 10,5m with the small error of 0,7%

Model Test of Bearing Capacity of WasteTire Assembly Foundation on Soft Soil Layer

2021 ◽  
Vol 69 (7) ◽  
pp. 263-269
Author(s):  
Me ti ◽  
Tri Harianto ◽  
Abdul Rachman Djamaluddin ◽  
Achmad Bakri Muhiddin
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Soft Soil ◽  
Soil Layer

Soft soil layer-tunnel interaction under seismic loading

2020 ◽  
Vol 98 ◽  
pp. 103329 ◽  
Author(s):  
Qiangqiang Sun ◽  
Daniel Dias ◽  
Luis Ribeiro e Sousa
Keyword(s):  
Soft Soil ◽  
Soil Layer ◽  
Seismic Loading

Stability Analysis of Narrow and Long Excavation in Soft Soil Area

2015 ◽  
Vol 723 ◽  
pp. 372-376
Author(s):  
Shi Chong Zhou ◽  
Li Li Gao ◽  
Dong Hui Wu ◽  
Yang Liu ◽  
Dong Yue Wang ◽  
...  
Keyword(s):  
Reduction Method ◽  
Soft Soil ◽  
Soil Layer ◽  
Spatial Effect ◽  
Strength Reduction ◽  
Strength Reduction Method ◽  
Present Stage ◽  
Support Structure ◽  
Finite Element Software ◽  
Sliding Stability

At the present stage of excavation design,the embedded depth of braced structure should meet the requirement of circular sliding stability when the bottom is soft soil. By increasing the embedded depth of support structure, the requirements of stability could be meet. In the normal design, the support structure must penetrate the soft soil layer when the bottom exist soft soil. While when the excavation is narrow and long, because of the obviously spatial effect, there is no need to determine the embedded depth based on the general circular sliding stability. In this paper, based on one the project example, calculate and analyze the similar stability using strength reduction method through the finite element software Plaxis and Midas.

The Influence of Pavement Construction on Embankment Settlement in Highway Extension Project

2013 ◽  
Vol 361-363 ◽  
pp. 1787-1793
Author(s):  
Xian Lin Wei ◽  
Yi Min Wang ◽  
Ze Min Zeng ◽  
Luo Zhang
Keyword(s):  
Soft Soil ◽  
Soil Layer ◽  
Composite Foundation ◽  
Standard Requirement ◽  
Construction Period ◽  
Small Influence ◽  
Load Carrying ◽  
Pavement Construction ◽  
Layer Deformation

In order to reduce the soft soil layer deformation due to pavement construction, equal preloading of pavement is usually adopted after embankment filling in soft ground region. But as the ground treatment effect of pile-supported and geosynthetic reinforced embankment is satisfactory with great load-carrying ability, the necessity of applying equal preload is worth discussing. Combined with the practice of Guangzhou-Sanshui expressway widening project, the settlements in surveying sections during the paving construction period in extension area were monitored. The monitoring data shows that pavement load had small influence on embankment settlement: the uneven settlement between newly widen and existing road is small and the post-construction settlements are controlled within the standard requirement. On the premise of guaranteeing the construction quality of composite-foundation and filling compaction degree, it is unnecessary to take equal preloading to avoid excessive embankment settlement caused by the pavement structure.

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