scholarly journals Prefabricated Vertical Drain (PVD) and Deep Cement Mixing (DCM)/Stiffened DCM (SDCM) techniques for soft ground improvement

2018 ◽  
Vol 143 ◽  
pp. 012002 ◽  
Author(s):  
D T Bergado ◽  
P V Long ◽  
S Chaiyaput ◽  
A S Balasubramaniam
Keyword(s):  
Ground Improvement ◽  
Soft Ground ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain ◽  
Soft Ground Improvement

scholarly journals A REVIEW OF ROAD EMBANKMENT STABILITY ON SOFT GROUND: PROBLEMS AND FUTURE PERSPECTIVE

2019 ◽  
Vol 20 (2) ◽  
pp. 32-56
Author(s):  
Rufaizal Che Mamat ◽  
Anuar Kasa ◽  
Siti Fatin Mohd Razali
Keyword(s):  
Ground Improvement ◽  
Future Perspective ◽  
Soft Ground ◽  
The Road ◽  
Prefabricated Vertical Drain ◽  
Key Factor ◽  
The Stability ◽  
Soft Ground Improvement ◽  
Intelligence Approach ◽  
Design Guidance

This paper presents an exhaustive review of the challenges faced in the construction of road embankments on soft ground and proposes a direction for future development. Frequently used techniques for soft ground improvement are discussed. The factors that contribute to the stability of the road embankment are reviewed by approach, results of past studies, and historical cases. The findings show that settlement, slope stability, and soil bearing capacity are all challenges to constructing the road embankment. Additionally, it is found that geometric data is a key factor in embankment design. Pre-loading with prefabricated vertical drain (PVDs) methods and lightweight fill were found to be widely used techniques in soft ground improvement. The information from this study can be used to develop design guidance systems, numerical modelling, and to give an overview and knowledge to other researchers who are or will conduct research in this field. Finally, future perspectives for research are related to predictions of factors that affect the stability of road embankment with an artificial intelligence approach. ABSTRAK: Kertas ini membentangkan ulasan kajian menyeluruh mengenai cabaran yang dihadapi dalam pembinaan benteng jalanraya di atas tanah lembut dan mencadangkan ke arah pembangunan kajian masa depan. Teknik-teknik penambahbaikan tanah lembut yang sering digunakan turut dibincangkan. Faktor- faktor yang menyumbang kepada kestabilan benteng jalanraya diulas dengan pendekatan kepada kajian lepas dan sejarah kes. Hasil kajian ini didapati bahawa enapan, kestabilan cerun dan keupayaan galas tanah merupakan cabaran dalam pembinaan benteng jalanraya. Selain itu, ia didapati bahawa data geometri merupakan faktor penting kepada rekabentuk benteng. Kaedah pra pembebanan dengan prefabrikasi saliran menegak (PVDs) dan isian ringan didapati teknik yang popular digunakan dalam pembaikkan tanah lembut masa kini. Maklumat dari kajian ini boleh digunakan untuk membangunkan sistem panduan reka bentuk, pemodelan berangka serta memberi gambaran dan ilmu kepada penyelidik lain yang sedang  atau akan menjalankan kajian dalam bidang ini. Akhir sekali, perspektif masa depan untuk penyelidikan berkaitan ramalan faktor-faktor yang mempengaruhi kestabilan embankment jalanraya dengan pendekatan kepintaran buatan.

Influence of Bending of Plastic Vertical Drain on Consolidation via Vacuum Preloading

2014 ◽  
Vol 644-650 ◽  
pp. 4826-4830
Author(s):  
Bin Bin Xu ◽  
Shotaro Yamada ◽  
Toshihiro Noda
Keyword(s):  
Ground Improvement ◽  
Ground Surface ◽  
Soft Ground ◽  
Finite Element Analyses ◽  
Vacuum Preloading ◽  
Vertical Drains ◽  
Bending Effect ◽  
Vertical Drain ◽  
Drainage Capacity ◽  
Soft Ground Improvement

The soft ground improvement employing vacuum preloading is widely used in Tianjin. In the application of vacuum preloading, the bending of plastic vertical drains (PVDs) often occurs accompanying the large settlement of the soft ground or the significant shear strain at the ground surface. In order to investigate the influence of bending of PVDs on the ground consolidation, three different bending shapes of PVDs are assumed and a series soil-water coupled finite element analyses are carried out. It is found that: 1) the macro-element method is available to take the bending effect of PVDs into consideration; 2) the bending at the bottom of PVDs has much impact on the consolidation of ground even though the hydraulic gradient at the bottom is much smaller than that at the top; 3) Due to the bending of PVDs at the bottom the drainage capacity is much influenced and the volumetric compression only occurs at the first few layers of the ground.

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 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%

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