A STUDY ON GROUND IMPROVEMENT TECNIQUE WITH IN-SITU MICROOGANISMS ISOLATED FROM JAPAN

Author(s):  
Rusutsu Ito
Keyword(s):  
Author(s):  
Pradeep U. Kurup ◽  
Mehmet T. Tumay

The electronic cone penetrometer is an important in situ investigation tool of choice for site characterization. Application of this proven concept of the cone penetration test (CPT) to highway design and construction control by miniaturization is described. A miniature cone penetrometer with a projected cone area of 2 cm2 has been developed and implemented in a continuous intrusion miniature cone penetration test system (CIMCPT). This device may be used for rapid, accurate, and economical characterization of sites and to determine engineering soil parameters needed in the design of pavements, embankments, and earth structures. The miniature cone penetration test (MCPT) gives finer details than the standard 10-cm2 cross-sectional area reference cone penetrometer. This makes the MCPT attractive for subgrade characterization, quality-control assessment, compaction control of embankments, and assessment of ground improvement effectiveness for transportation infrastructure. In situ calibration of the CIMCPT system was conducted at a highway embankment site in Baton Rouge, Louisiana. MCPT penetration profiles were compared with those obtained by using the standard cone penetrometer at the same site. The tip resistance of the MCPT was 10 percent higher than that of the reference CPT. The sleeve friction and friction ratio of the reference CPT were higher than that of the MCPT by 12 and 23 percent, respectively. Calibration was also performed to determine empirical cone factors required for estimating undrained shear strength from MCPT data.


2012 ◽  
Vol 06 (04) ◽  
pp. 1250017 ◽  
Author(s):  
HELEN MITRANI ◽  
S. P. G. MADABHUSHI

Many typical ground improvement techniques that are used for liquefaction remediation, such as in situ densification, are not appropriate for application under existing buildings and more novel techniques are required. This paper describes centrifuge tests investigating the performance of rigid containment walls as a liquefaction remediation method. A simple frame structure, founded on a deep layer of loose, liquefiable sand was tested under earthquake shaking. Centrifuge tests were then carried out with containment walls around the base of the structure, extending through the full depth of the liquefiable layer and also partial depth. It is found that rigid containment walls can be very effective in reducing structural settlements primarily by preventing lateral movement of the foundation sand but the impermeability of the walls may also be important. Improvements in structural settlement are observed even when the walls do not extend through the full depth of the liquefiable layer, if the depth of the walls is greater than the depth of the free field liquefaction. In addition, it is found that the accelerations of the structure are not increased, provided there is no rigid, structural connection between the structure and the containment walls.


Author(s):  
Josepha D. Celes ◽  
Paul W. Mayne

In situ plasma magmavication is a powerful and expedient technique for melting soil that subsequently cools to form a glassy igneous rock. A nontransferred arc plasma torch provides temperatures exceeding 4000°C that can be positioned within boreholes as a means of ground improvement or for environmental restoration of contaminated soils. The process is similar to in situ vitrification by embedded graphite electrodes, yet the nontransferred arc is a considerably more efficient process. The artificial rock can be left in place or, alternatively, may be exhumed and stored. The effectiveness of plasma remediation on uncontaminated and contaminated kaolin was investigated through a preliminary series of laboratory chamber tests with small dosages of chemical, biological, and nuclear surrogates. It is believed that the process pyrolizes organic contaminants, while locking the inorganic contaminants within the glass matrix. Measurements in compressive strength, stiffness, porosity, and mass density verified the transformation of soil to rock with improved material characteristics.


2005 ◽  
pp. 15-25
Author(s):  
Hiroshi TAKAHASHI ◽  
Tetsuo FUJIYAMA ◽  
Takeshi ISHIGURO ◽  
Kenichi AZUMA ◽  
Takashi ITO

2001 ◽  
Vol 38 (6) ◽  
pp. 1241-1253 ◽  
Author(s):  
Der-Her Lee ◽  
C Hsein Juang ◽  
Chi-Sheng Ku

This paper examines the liquefaction performance of soils at the site of a partially completed ground improvement project at the Chang-Hwa Coastal Industrial Park during the 1999 Chi-Chi earthquake in Taiwan. The site is on land reclaimed by hydraulic filling. To meet the need of a planned construction, site characterization was carried out with standard penetration tests (SPTs) and cone penetration tests (CPTs) at 13 locations. Dynamic compaction was later performed to mitigate the potential liquefaction hazards at this site. Before completion of the ground improvement work, the site experienced a major earthquake, the Chi-Chi earthquake (magnitude Mw = 7.6). Evidence of liquefaction was observed in this earthquake in the unimproved area but not in the improved area. After the earthquake, additional site exploration was carried out using SPTs and CPTs. The data from these in situ tests carried out before and after the earthquake and in areas with and without ground improvement are analyzed and the results are reported.Key words: ground improvement, in situ tests, liquefaction, earthquake.


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