• Proceedings of the Korean Geotechical Society Conference
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• 2005.10a
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• pp.425-428
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• 2005

To resolve land demand by the development of various industries and the cityward tendency of population, the construction of ultra-soft ground that is unused in the past has been progressing with activity. The ultra-soft ground has very small shear strength and large deformation, so leads to many problems in ground improvement in construction. In order to dispose of these problems, it is necessary to develope the chemical materials that can be applied to the surface stabilization of ultra-soft ground. In this study, the new ground treatment that is using cement and SCS is compared, analyzed with existing ground treatment. In addition, through the laboratory tests that check the characteristic of congealment and strength, the application of SCS in field is affirmed.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.998-1001
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• 2010

Most firming agent used in Korea is cement-firming agent. Cement-firming agent absorb water for combination, and then it makes ettringite. Through this chemical process, soft ground is firmed by cement-firming agent. Although most cement-firming agent used in Korea made from CSA, it relies on imports. Therefore, the development of soft ground firming agent using new materials is required. In this study, we suggested that EAF reduction slag not used for anything in the steel industry is available for material of soft ground firming agent. If EAF reduction slag is used in soft ground firming agent, it will be possible to solve the problem with treatment of slag and improvement of soft ground.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.36 no.4
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• pp.705-713
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• 2016

For the soft ground construction, the factors not considered in the design stage occurs in the construction stage so that they cause the increase of the construction cost due to the structural stability and the design change. The subject of the study is the construction section of the industrial complex access road made in the Ochang region of Chungcheongbuk-do. The study is concerned with selecting the soft ground handling method such as the replacement method using rock debris and the surcharge reflecting the service load as the soft ground handling measure and analyzing the effect of reducing the construction cost with the stability of structures and the reduction of the construction period. The soft ground in the study section consists of sandy and cohesive soil and is 2.4m to 5.5m deep. It is distributed unevenly between the 1.5m to 5.9m stratums under the ground surface. Settlement is not serious, but the future uneven settlement and difference are expected so that the future settlement behavior is estimated by analyzing the site measurement results after the soft ground treatment. Moreover, in consideration of the regional characteristics and economic efficiency, soil with good quality is replaced with rock debris as the replacement material so that 29% of the construction cost is reduced due to the increase of stability and the reduction of duration. If the estimation of the dispersion of the pore water pressure within the dam body and the change of the underground water level and the relation of the actually measured soft ground with consolidation is studied further on the basis of the study, it is expected that the behavior of the soft ground will be correctly estimated in various site conditions.

• Journal of the Korean Professional Engineers Association
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• v.37 no.3
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• pp.50-53
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• 2004

JSP(Jumbo Super Pile) method is a foundation treatment of mixing in depth, one of the soft ground improvement methods through which settlement and deformation of ground foundation is prevented. An example of this method which is applied for the foundation design of a new drainage pumping station is Introduced, and another applied example for an existing pumping station which is built on soft foundation is also introduced.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09a
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• pp.336-345
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• 2010

GS E&C was awarded the contract for the construction of Hanoi - Hai Phong Expressway Package EX-7 from Station Km 72+000 to Station Km 81+300 in December 2008. This project is the $7^{th}$ contract package of the 105.5 km long expressway near Hai Phong city, which includes a FCM-styled bridge along with high embankments over soft ground. For these high embankments, there is a need to treat the soft soil for improving the overall stability during construction and for reducing the post-construction settlement of the expressway. The Designer of this project had adopted four (4) different types of ground improvement techniques to treat the soft ground, including the prefabricated vertical drains (PVD), sand drains (SD), pack drains (PD, or sometimes called packed sand drains), and sand compaction piles (SCP). The main focus of soft soil treatment should be paid attention to the residual settlement after construction. In current design, however, it appeared that the secondary compression (or creep) of the improved soil layer and the consolidation settlement of the lower untreated compressible soil layer have been neglected in the estimation of the post-construction settlement. These uncalculated residual settlements may not only unsatisfy the design criteria but also raise serious problems during service period of this expressway. In this paper, the subsoil condition and current design were reviewed focusing on the employed soft soil treatment method and expected residual settlement.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03b
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• pp.615-622
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• 2000

This paper is relate to the result of pilot test in Asan. In order to evaluate the characteristics of behavior and deformation in Asan and to analyse the effect of soft ground treatment, preloading, two types of paper drain and pack drain were constructed in the ground. Settlement gauges, pressure meters, pressure cells and ground water gauges were monitored and also borings and piezoncone tests were performed. As a result of analyse, every vertical drained area was consolidated over 90% degree of consolidation but preloaded area was not reached to 90%.

• Explosives and Blasting
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• v.10 no.1
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• pp.8-19
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• 1992

• Journal of the Korean GEO-environmental Society
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• v.20 no.5
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• pp.39-46
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• 2019

Most of the soil used for reclamation is marine clay generated from dredging construction.The soft ground made of dredged clay has high water content and high compressibility, so the bearing capacity of the ground is very weak and it is difficult to enter the ground improvement equipment. Therefore, surface hardening treatment method is used to enter equipment prior to full-scale civil engineering work, and stabilizer is mainly used for cement series. Cement-based stabilizers have the advantage of improving the ground in a short period of time and have excellent economic efficiency, but they are disadvantageous in that they cause environmental problems due to leaching of heavy metals such as hexavalent chromium. In this study, environmental effects evaluation of dredged clay mixed with normal portland cement and environmentally friendly stabilizer was evaluated, and uniaxial compressive strength test and indoor model test were conducted to confirm the bearing capacity characteristics of the solidified layer.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.15 no.4
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• pp.197-206
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• 2003

A new type of breakwater, which can be applicable to soft ground without special treatment because of its light self weight and structural characteristic of bottom wall, has recently been developed. The objective of this study is to propose an evaluation method of safety factor for the new type of breakwater considering 3 categories of sliding, overturning, and bearing capacity. Previous method for gravity type of breakwater was modified and the proposed method was verified by comparing the safety factors with maximum lateral displacements, which were obtained from finite element analysis for various types of breakwaters and ground conditions. The results showed the newly proposed evaluation method of safety factors could reasonably be utilized.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.569-574
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• 1999

In Soft ground of south-western coast of our country necessity of marine indutrial complex and container facility has been remarkable. Site construction for habor facility is one of the most urgent problems. Consolidation of dredged fill has become important task. In addition, volume change of dredged fill should be examined carefully. This study dealt with consolidation of dredged fill by PCDDF and in order to secure trafficability of heavy equipment for surface treatment should be studied.