scholarly journals Evaluation on Improvement Zone of Foundation after Dynamic Compaction

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.

INNOVATIVE SOFT SOIL IMPROVEMENT BY VACUUM DE-WATERING AND DYNAMIC COMPACTION

2016 ◽  
Vol 3 (1) ◽  
Author(s):  
Tuncer B. Edil
Keyword(s):  
Large Scale ◽  
Ground Improvement ◽  
Soft Soil ◽  
High Vacuum ◽  
Cohesive Soil ◽  
Soil Improvement ◽  
Economic Benefits ◽  
Dynamic Compaction ◽  
Environmental Benefits ◽  
Improvement Method

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.

The Experimental Research of Slurry Improvement with Different Kinds of Vertical Drains under New Vacuum Conditions

2013 ◽  
Vol 405-408 ◽  
pp. 396-401
Author(s):  
Jian Chen ◽  
Qiao Liang Tang ◽  
Shi Jing Liu
Keyword(s):  
Experimental Research ◽  
Ground Improvement ◽  
Soil Improvement ◽  
Vacuum Preloading ◽  
Prefabricated Vertical Drains ◽  
Vertical Drains ◽  
Drain Spacing ◽  
Soil Zone ◽  
Reclaimed Soil ◽  
Improvement Effect

The results of experimental research are presented and discussed with focus on the ground improvement effect of slurry with different kinds of vertical drains under new vacuum conditions. In these conditions, horizontal sand cushion, which is requested in regular vacuum preloading method, is cancelled. Vertical drains are connected with sealed pipes, so the vacuum head can be transmitted into vertical drains without decreasing. For the experimental research, slurry taken from reclaimed soil zone is placed into six model casing boxes. Different kinds of vertical drains (prefabricated vertical drains (PVDs) and sand drains) are installed into the soil with different spacing (0.4 m and 0.8 m). A vacuum pressure of 80 kPa was applied continuously for 90 days. The effect of filter type of PVD, type of vertical drain and drain spacing under new vacuum preloading condition to slurry soil improvement is examined. Test results show that this new vacuum preloading condition can transmit vacuum head into vertical drains efficiently and the effect of drain filter to slurry improvement is affected by the drain spacing.

The Analysis of Stress Distribution of Hammer Bottom during Dynamic Compaction on Sandy Soil Foundation

2011 ◽  
Vol 250-253 ◽  
pp. 1460-1463
Author(s):  
Jian Qi Wu ◽  
Jian Hong Deng ◽  
Xiao Ping Wang
Keyword(s):  
Comparative Analysis ◽  
Stress Distribution ◽  
Sandy Soil ◽  
Field Monitoring ◽  
Dynamic Compaction ◽  
Dry Density ◽  
Test Results ◽  
Red Sandstone ◽  
Soil Foundation

Obtained stress distribution of hammer bottom according to the analysis of horizontal and vertical red sandstone fill dry density of the hammer bottom after dynamic compaction; affirmed the stress distribution situation of the hammer bottom through comparative analysis of the test results by laboratory and field monitoring.

Remediation Effect of Biomass Amendment on the Physical-Chemical Performance and Sustainable Utilization of Sandy Soil

2021 ◽  
Vol 45 (1) ◽  
pp. 33-42
Author(s):  
Zibei Ren ◽  
Ming Li ◽  
Yanzhe Hui ◽  
Zengwang Ma ◽  
Jiancai Gu
Keyword(s):  
Sandy Soil ◽  
Saline Soil ◽  
Animal Husbandry ◽  
Soil Improvement ◽  
Sustainable Utilization ◽  
Test Results ◽  
Degraded Soil ◽  
Four Dimensions ◽  
Physical Chemical ◽  
Biological Performance

Soil desertification affects the service functions of the ecosystem. In severe cases, it even causes a decline in agricultural productivity and shrinkage of animal husbandry, posing a threat to regional eco-environment and economic sustainability. The previous research on soil remediation research mainly concentrates on heavy metal degradation, saline soil improvement, and eroded and degraded soil improvement. There is little report on the biomass improvement and restoration of sandy soil. Therefore, this paper explores the remediation effect of biomass amendment on the physical-chemical performance and sustainable utilization of sandy soil in Huangyangtan, the largest sandy land in northern China’s Hebei Province. Specifically, the authors detailed the strategies to measure the physical-chemical indices and microbial diversity of Huangyangtan sandy soil, and introduced the materials and mode of the biomass amendment test on Huangyangtan sandy soil, followed by an elaboration on the test results. The influence of different test fertilizers on the soil was analyzed in four dimensions, namely, physical performance, chemical performance, biological performance, and crop yield. The results show that biomass amendment can effectively remediate sandy soil, and promote its sustainable utilization.

scholarly journals Factors affecting clay dispersion in oxisols treated with vinasse

2016 ◽  
Vol 37 (6) ◽  
pp. 3997 ◽  
Author(s):  
Thadeu Rodrigues de Melo ◽  
Tiago Santos Telles ◽  
Walquiria Silva Machado ◽  
João Tavares Filho
Keyword(s):  
Sandy Soil ◽  
Physical Quality ◽  
Factors Affecting ◽  
Clay Dispersion ◽  
Water Dispersible ◽  
Dispersive Effect ◽  
Bivalent Cations ◽  
Chemical Attributes ◽  
Almost All ◽  
Dispersible Clay

Vinasse is a potassium-rich waste generated in large amounts by the ethanol production that, applied in the soil, can promote changes in water dispersible clay and in its physical quality. The aim of this study was to evaluate the clay dispersion of Oxisols after vinasse application and correlate it with some chemical attributes. Samples were collected in two Oxisols (155 and 471 g of clay kg-1), put in pots, received dosages of vinasse (0, 50, 100, 150 and 200 m3 ha-1) and remained incubated during 120 days. Phosphorous, organic carbon, pH H2O, pH KCl, pH CaCl2, Al3+, H+Al3+, Ca2+, Mg2+, K+, Na+, Delta pH and the proportion between monovalent and bivalent cations have been evaluated and correlated with the clay flocculation degree. Vinasse changed almost all chemical variables in both soils and increased the flocculation in the sandy soil, but did not change the clayey one. Delta pH, Mg2+ and K+ significantly correlated with the flocculation degree in the sandy soil. It is possible to conclude that the dispersive effect of K+ added by vinasse are irrelevant, considering the flocculant effect caused by the increment in Mg2+ and Delta pH after vinasse application.

Deep Dynamic Compaction: Practical and Cost-Effective Ground Improvement at the Port of Long Beach

Ports 2013 ◽  
2013 ◽  
Author(s):  
Mariusz P. Sieradzki ◽  
Bartlett W. Patton ◽  
Douglas J. Sereno ◽  
Paul Wehrlen
Keyword(s):  
Ground Improvement ◽  
Cost Effective ◽  
Dynamic Compaction ◽  
Long Beach

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

1997 ◽  
Vol 1 (3) ◽  
pp. 147-155 ◽  
Author(s):  
W. F. Van Impe ◽  
F. De Cock ◽  
J. P. Van Der Cruyssen ◽  
J. Maertens
Keyword(s):  
Soil Improvement ◽  
Dynamic Compaction

Factors Affecting Alkalinity Concentrations of Streamwater during Snowmelt in Central Ontario

1989 ◽  
Vol 46 (10) ◽  
pp. 1658-1666 ◽  
Author(s):  
Lewis A. Molot ◽  
P. J. Dillon ◽  
B. D. LaZerte
Keyword(s):  
Organic Acid ◽  
Headwater Streams ◽  
Base Cations ◽  
Base Cation ◽  
Major Contributor ◽  
Factors Affecting ◽  
Concentration Changes ◽  
Highly Correlated ◽  
Spring Snowmelt

Relative contributions of changes in base cations and acid anions to alkalinity decreases during spring snowmelt in 1984–86 were analyzed for 15 headwater streams and lake outflows in three central Ontario catchments. During episodes, concentration changes in ions which contributed to alkalinity decreases were partially offset by smaller changes in other ions which contributed to alkalinity increases. The major contributor to alkalinity depressions was base cation dilution by snowmelt water. Akalinity depressions were more likely to be dominated by SO42− increases in streams that were more acidic. Neither nitrate nor organic acid anions were significant contributors to alkalinity depressions. Discharge was highly correlated with alkalinity in a circumneutral stream but not in an acidic stream and is consistent with dilution being less important as a cause of alkalinity depressions as streams become more acidic.

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