Soil improvement experiences in Belgium: part I. Overview and dynamic compaction

Recently, an innovative soft soil improvement method was advanced in China by integrating and modifying vacuum consolidation and dynamic compaction ground improvement techniques in an intelligent and controlled manner. This innovative soft soil improvement method is referred to as “High Vacuum Densification Method (HVDM)” to reflect its combined use of vacuum de-watering and dynamic compaction techniques in cycles. Over the past ten years, this innovative soft soil improvement technique has been successfully used in China and Asia for numerous large-scale soft soil improvement projects, from which enormous time and cost savings have been achieved. In this presentation, the working principles of the HVDM will be described. A discussion of the range of fine-grained, cohesive soil properties that would make them ideal for applying HVDM as an efficient ground improvement method will be discussed. The economic benefits and environmental benefits of HVDM are elucidated.

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Evaluation on Improvement Zone of Foundation after Dynamic Compaction

Applied Sciences ◽

10.3390/app11052156 ◽

2021 ◽

Vol 11 (5) ◽

pp. 2156

Author(s):

Chong Zhou ◽

Chenjun Yang ◽

Hui Qi ◽

Kai Yao ◽

Zhanyong Yao ◽

...

Keyword(s):

Sandy Soil ◽

Ground Improvement ◽

Soil Improvement ◽

Dynamic Compaction ◽

Impact Point ◽

Weak Zone ◽

Factors Affecting ◽

Improvement Effect ◽

Drop Number ◽

Highly Correlated

Dynamic compaction (DC) is one of the most popular methods for ground improvement. To solve the problem of the factors affecting the sandy soil improvement effect and estimate the effective improvement range under DC, the influences of drop number, drop energy, tamping distance, tamper radius, and drop momentum on the relative degree of improvement were investigated. Three normalized indicators Δδz,i, ΔδA,i, and ΔδU,i were derived to evaluate the weak zone and corresponding improvement effect. For multipoint tamping, it is found that the improvement depth and the improvement of the weak zone are highly correlated with drop energy and drop momentum, while the influence of the drop number and tamper radius is relatively smaller. The improvement of the weak zone and the improvement depth decrease with tamping distance, whereas the improvement area increases with tamping distance. The soil compacted by the previous impact point will be improved to a lesser extent with impact at subsequent impact points. It is also noted that drop energy had better not exceed the saturated drop energy in DC design. Based on the parametric study, a formula considering the various factors of DC was put forward, with the validation by two field cases of DC.

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EFEK GAYA VERTIKAL PADA TANAH DENGAN INDEKS PLASTISITAS TINGGI TERHADAP WILAYAH SEKITAR PROYEK DI JAKARTA UTARA

JMTS: Jurnal Mitra Teknik Sipil ◽

10.24912/jmts.v3i2.7080 ◽

2020 ◽

Vol 3 (2) ◽

pp. 487

Author(s):

Staventram Inri ◽

Alfred Jonathan Susilo

Keyword(s):

Bearing Capacity ◽

Soil Compaction ◽

Shear Failure ◽

Pore Water Pressure ◽

Water Pressure ◽

Soil Improvement ◽

Dynamic Compaction ◽

Lateral Movement ◽

Theoretical Predictions ◽

Driven Pile

Soil improvement is common in construction work to increase the bearing capacity of the soil so the soil can carry the burden of construction which will stand on that soil. The method often used is soil compaction to increase bearing capacity. Soil compaction results in a lateral movement of soil particles and causes an increase in soil pore water pressure. Soil compaction here uses drum roller and dynamic compaction. This gives an effect at a certain distance and has the potential to damage the surrounding buildings. Therefore, the engineer needs to predict a safe distance from the effects of the compaction process. This research conducted with theoretical predictions about the amount of lateral movement due to compaction with certain formulas. The same thing will happen when the driven pile is piling, it will cause around the pile lift up (pile heaving). The results of this theoretical prediction will be compared then compare with the results of measurements of lateral movements performed using general shear failure from Terzaghi method and stress distribution Boussinesq method. Both of the results will be compared as conclusions.AbstrakPerbaikan tanah sudah umum dilakukan dalam pekerjaan konstruksi dengan tujuan untuk meningkatkan daya dukung tanah agar dapat memikul beban konstruksi yang akan berdiri di atasnya. Metode yang sering digunakan yaitu pemadatan tanah untuk meningkatkan daya dukungnya. Pemadatan tanah mengakibatkan desakan butiran tanah ke arah lateral serta menimbulkan kenaikan tekanan air pori tanah. Pemadatan disini menggunakan tandem roller dan dynamic compaction. Hal ini memberikan pengaruh hingga jarak tertentu dan berpotensi merusak bangunan di sekitar. Oleh karena itu, perlu diprediksi jarak yang aman dari pengaruh proses pemadatan. Penelitian ini dilakukan dengan prediksi teoritis besarnya pergerakan tanah ke arah lateral akibat pemadatan dengan formula tertentu. Hal yang serupa juga sama ketika tiang pancang ditumbuk, akan menyebabkan tiang di sebelahnya terangkat (pile heaving). Hasil prediksi secara teori ini kemudian dibandingkan dengan hasil pengukuran kegagalan geser berdasarkan metode Terzaghi dan distribusi tegangan Boussinesq. Hasil keduanya akan dibandingkan sebagai kesimpulan.

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