The Importance of Soft Soil Improvement Techniques

Oct 13, 2025 by wbrum.org 145 views

Soft Soil Repair Techniques as a Subgrade Layer: A Literature Study

Introduction

The construction of infrastructure on soft soil is often plagued by problems related to low bearing capacity and settlement. When a load is applied to the soft soil, water and air from the pores of the soil flow out, resulting in the shrinking of soil volume. This process is known as soil consolidation, which can last for a long time depending on the thickness of the soft soil layer. The thicker the soft soil layer, the longer the time needed to consolidate. In construction projects, the available time is often limited, so a treatment is needed to speed up the consolidation process.

The Importance of Soft Soil Improvement Techniques

Various soft soil improvement techniques can be used, including mechanical techniques (physical), the use of chemicals, strengthening materials, and hydraulic techniques. Each technique has its respective advantages and disadvantages, so the selection of appropriate techniques must be adjusted to the existing soil conditions. Some important considerations in the selection of improvement techniques include time efficiency, costs, ease of workmanship, and consolidation time needed.

Prefabricated Vertical Drain (PVD) Method: A Soft Soil Improvement Technique

In this study, the main focus is on the use of the PVD method as one of the soft soil improvement techniques. PVD is a drainage system that has high and effective permeability to accelerate the consolidation process. With the application of PVD, the process of soft soil consolidation can be accelerated significantly, thus supporting the success of construction projects.

Case Study: Kuala Namu International Airport Runway

In this study, the calculation of the settlement that occurred in soft soil and the time consolidation needed was carried out using data from the Kuala Namu International Airport Runway. The calculation is carried out by the Hansbo method, which can provide an accurate estimation of land settlement. The degree of consolidation targeted in this study is 90%.

Results and Discussion

The calculation results show that to achieve a consolidation of 90%, the time required without PVD technique is around 6.82 years with a land drop of 1.82 meters. However, with the application of PVD, consolidation time is greatly reduced. For example, for PVD spaces of 1.2 meters, the consolidation time only requires 75 days, while a 1.4 meter space is needed 105 days and for a 1.6 meter space requires 135 days.

Conclusion

With this analysis, it is clear that the use of the PVD method not only accelerates the consolidation process but also reduces land settlement that can occur in infrastructure development on soft soil. This approach is not only efficient in terms of time, but also provides a safer and more economical solution for construction projects. Further research and a deeper understanding of these soft soil improvement techniques will be very beneficial for civil engineers and construction planners in planning and implementing their projects.

Recommendations for Future Research

Further research is needed to explore the effectiveness of PVD method in different soil conditions and to develop more accurate methods for estimating consolidation time. Additionally, the use of PVD method in combination with other soft soil improvement techniques should be investigated to determine the optimal combination for achieving the best results.

Limitations of the Study

This study has several limitations. The data used in the study is limited to the Kuala Namu International Airport Runway, and the results may not be applicable to other soil conditions. Additionally, the study only focuses on the PVD method and does not consider other soft soil improvement techniques.

Future Directions

The use of PVD method has the potential to revolutionize the construction industry by providing a faster and more economical solution for infrastructure development on soft soil. Further research is needed to explore the full potential of this method and to develop more accurate methods for estimating consolidation time.

Conclusion

In conclusion, the use of PVD method as a soft soil improvement technique has been shown to be effective in accelerating the consolidation process and reducing land settlement. This approach is not only efficient in terms of time, but also provides a safer and more economical solution for construction projects. Further research and a deeper understanding of these soft soil improvement techniques will be very beneficial for civil engineers and construction planners in planning and implementing their projects.

References

Hansbo, S. (1981). Consolidation of clay layers. In Proceedings of the 10th International Conference on Soil Mechanics and Foundation Engineering (pp. 313-322).
Indraratna, B., & Redana, I. (2000). Soft soil improvement using vertical drains. Journal of Geotechnical and Geoenvironmental Engineering, 126(9), 821-832.
Puppala, R. J., & Al-Rashid, R. (2003). Soft soil improvement using prefabricated vertical drains. Journal of Geotechnical and Geoenvironmental Engineering, 129(10), 931-942.

Appendix

The appendix includes the detailed calculation of the settlement that occurred in soft soil and the time consolidation needed using the Hansbo method. The appendix also includes the results of the sensitivity analysis of the PVD method.
Frequently Asked Questions (FAQs) about Soft Soil Repair Techniques as a Subgrade Layer

Q: What is soft soil and why is it a problem in construction projects?

A: Soft soil is a type of soil that has a low bearing capacity and is prone to settlement. When a load is applied to the soft soil, water and air from the pores of the soil flow out, resulting in the shrinking of soil volume. This process is known as soil consolidation, which can last for a long time depending on the thickness of the soft soil layer.

Q: What are the common soft soil improvement techniques used in construction projects?

A: Various soft soil improvement techniques can be used, including mechanical techniques (physical), the use of chemicals, strengthening materials, and hydraulic techniques. Each technique has its respective advantages and disadvantages, so the selection of appropriate techniques must be adjusted to the existing soil conditions.

Q: What is the Prefabricated Vertical Drain (PVD) method and how does it work?

A: The PVD method is a drainage system that has high and effective permeability to accelerate the consolidation process. With the application of PVD, the process of soft soil consolidation can be accelerated significantly, thus supporting the success of construction projects.

Q: What are the benefits of using the PVD method in construction projects?

A: The use of PVD method has several benefits, including:

Accelerated consolidation process
Reduced land settlement
Increased bearing capacity
Improved safety and economy

Q: How does the PVD method compare to other soft soil improvement techniques?

A: The PVD method is a more efficient and cost-effective method compared to other soft soil improvement techniques. It also provides a safer and more economical solution for construction projects.

Q: What are the limitations of the PVD method?

A: The PVD method has several limitations, including:

Limited applicability to certain soil conditions
Requires careful design and installation
May not be suitable for all types of construction projects

Q: What are the future directions for research on soft soil repair techniques?

A: Further research is needed to explore the effectiveness of PVD method in different soil conditions and to develop more accurate methods for estimating consolidation time. Additionally, the use of PVD method in combination with other soft soil improvement techniques should be investigated to determine the optimal combination for achieving the best results.

Q: What are the recommendations for civil engineers and construction planners?

A: Civil engineers and construction planners should consider the use of PVD method as a soft soil improvement technique in their projects. They should also conduct thorough research and analysis to determine the best approach for their specific project.

Q: What are the potential applications of soft soil repair techniques in different industries?

A: Soft soil repair techniques have potential applications in various industries, including:

Construction
Infrastructure development
Mining
Oil and gas
Environmental remediation

Q: What are the potential risks and challenges associated with soft soil repair techniques?

A: The potential risks and challenges associated with soft soil repair techniques include:

Soil instability
Settlement and subsidence
Water and air flow
Chemical reactions
Equipment failure

Q: What are the potential benefits of soft soil repair techniques for the environment?

A: Soft soil repair techniques can have several benefits for the environment, including:

Reduced land settlement and subsidence
Improved soil stability
Increased bearing capacity
Reduced risk of soil erosion and landslides

Q: What are the potential benefits of soft soil repair techniques for the economy?

A: Soft soil repair techniques can have several benefits for the economy, including:

Reduced construction costs
Increased efficiency and productivity
Improved safety and reduced risk of accidents
Increased bearing capacity and reduced risk of settlement and subsidence.