The cone penetration test is one of the most important and convenient tools for soil investigations. In recent decades, many efforts have been made to extend its applications to various fields in geotechnical engineering. This paper presents a newly developed dynamic cone penetration test with measurement of the pull-out resistance, which is named “Penetration & Pull-out Test (PPT)”. PPT consists of the dynamic penetration test and the quasi-static pull-out resistance test. “N-value”, the number of blows for penetration into soil under the undrained condition is measured from the dynamic penetration test, while the friction resistance of soil under the drained condition is measured from the quasi-static pull-out test. The validation test results indicate that PPT is highly useful for mitigation of liquefaction-induced problems due to earthquakes. PPT is a break-proof device because it is equipped without electrical sensor at the tip of the cone. As the future direction of this study, we will develop a more economical and simpler in-situ apparatus for judging the liquefaction susceptibility of soils.

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In the prolog of this work the short description of the last earthquakes which have occurred in recent years in the Republic of Kazakhstan is given. Further more detailed information on earthquake consequences is stated: destruction scales, order of works at elimination of consequences of an earthquake, methods of strengthening of buildings. At the end of article it is spoken about works of KAZNIISSA done in the field of elimination of consequences of an earthquake for existing building.

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In this paper, the formation of flower structures and the Riedel shear structures inside a ground above a strike slip fault were reproduced numerically using the soil-water coupled finite deformation analysis code GEOASIA that mounts the SYS Cam-clay model on it. The analysis results revealed that the Riedel shear structures accompanied by flower structures developed as a bifurcation mode triggered by initial imperfections showing plastic expansion with loss of overconsolidation on the shear bands.

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Korea is located on the eastern margin of the Eurasian Plate. Although it is far from a plate boundary (the closest distance is about 400-500km), the seismicity is affected by the complex interaction of the collision of the Indo-Australian and the Eurasian plates, and the subduction of the Philippine Sea plates beneath the Eurasian plate along the Japan and the Ryukyu trenches respectively. This paper presents a study on seismic horizontal ground motions for rock sites in South Korea. As part of the study, historical and recent earthquakes have been used. A seismic source model has been developed which incorporates the Korean local tectonic and subduction of the Philippines Sea Plate. Also, recently published empirical and stochastic attenuation relationships have been have been adopted. The seismic hazard for spectral accelerations at structural periods of short period (0.1s) and 1.0 seconds having a 2% probability of being exceeded in the next 50 years are presented as hazard contour maps across South Korea. De-aggregation plots are also shown for a few major cities to investigate the earthquake magnitude and distance combinations. The results show that the subduction zones near Japan contribute significantly to the seismic hazard in South Korea particularly for the longer structural period ground motion.

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The purpose of this study was to create a real-time liquefaction hazard map at national level by taking into consideration the differences between the site acceleration and intensity scale distribution depending on the occurrence site when an earthquake would take place. To this end, the two sub-studies were conducted. The first was to create a liquefaction hazard map for each site acceleration for an earthquake based on the evaluation method of macro-liquefaction for each site acceleration. The second was to establish a real-time liquefaction hazard map DB that could be linked with the system for earthquake disaster prevention by integrating the liquefaction hazard maps of all the site accelerations. First, this study conducted the liquefaction evaluation by developing the metropolitan area liquefaction evaluation program based on Excel in order to use approximately 14,040 metropolitan area site data. This study deducted the Liquefaction Potential Index (LPI) for each site depth by using the correction Seed & Idriss method and the site amplification coefficient satisfying South Korea’s earthquake-resistant criteria in relation to the liquefaction evaluation. This metropolitan area liquefaction evaluation program is able to skip the site response analysis for earthquake used when creating a facility-centric hazard map in order to create a liquefaction hazard map at city, provincial and national levels. Also, this metropolitan area liquefaction evaluation program is able to substitute it with a site amplification coefficient in order to reduce the duration of liquefaction evaluation. As a result, it was possible to reduce the time taken to create a liquefaction hazard map by approximately 50,000 hours. In the end, the liquefaction hazard map for each site acceleration was created based on the interval of 0.04g from 0.06g to 0.38g. In regard to the second sub-task that was to create a real-time liquefaction hazard map, the basemap that would become a basis of creating a liquefaction hazard map was designed to be linkable after using the cell unit of 2Km by 2Km used by the system for earthquake disaster prevention. Then, this study deducted the relational formula through the earthquake acceleration for each coordinate and the correlation with LPI. At this time, the optimal relational formula was applied in relation to LPI for each site acceleration and the correlation between the relational formulas among those two-variable 4 relational formulas. For the verification of this study, a real-time liquefaction hazard map of earthquake scale 6.0 was created in consideration of the difference in the site distribution for an earthquake as to Hongseong Earthquake and Odae-mountain Earthquake, which took place previously.

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The aim of the study reported in this paper is to reveal the long-term settlement of Holocene clay ground after the 2011 off the Pacific Coast of Tohoku earthquake. The authors took level readings six times across Urayasu City, Chiba Prefecture, during the period from April 2011 to April 2013. The result is a chronological record of changes in settlement of first-order benchmarks and survey points showing that long-term ground settlement is taking place due to the earthquake. In the Phase I reclaimed land (which was constructed between 1968 and 1975), the settlement rate is shown to be approximately 6 mm/year, more than twice the rate of settlement before the earthquake. In the Phase II reclaimed land (which was constructed between 1978 and 1980), the settlement behavior is found to differ according to whether the reclaimed land had been improved or not. Further, natural alluvial lowland has not settled since the earthquake.

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In order to maintain the function of Nagoya Port, 1.3 million m3 soil must be dredged every year which is currently filled at Nagoya Port Island (hereinafter, PI) as a temporary disposal area. However, the initial envisioned capacity of the PIs to accept dredged soil has already been exceeded, even though the temporary banks built on top of the reclaimed ground have increased their capacities. Therefore, should a megathrust earthquake occur, it is likely that, in addition to damaging the revetment and temporary banks, the earthquake would cause large volumes of high-piled dredged soil to flow into the harbor, where it could block ship channels. This would not only reduce the functionality of Nagoya Port, it would also lead directly to delays in disaster relief and recovery/reconstruction support. For this reason, seismic assessment of the PIs and improvements to their earthquake resistance are urgent issues. In this study, we used a computer simulation to reproduce a PI in its current state, while taking into consideration its actual construction history, in order to gain an understanding of the damage that would occur during and after the largest envisioned Nankai Trough earthquake. Furthermore, the model used predicted how earthquake damage would progress if dredged soil were to continue to be added onto the PI without restriction. The main conclusions are as follows. 1) If the current situation remains unchanged, a certain amount of deformation would occur on the PI as a result of the earthquake, but the damage extent would not be such that dredged soil would flow into the harbor. 2) On the other hand, if the existing height were raised by 4 m, it would be impossible to prevent the lateral displacement of dredged soil, and there would be a high risk of dredged soil flowing into the harbor. These results indicate that continuing to raise the height of the reclaimed land is dangerous in terms of PI earthquake resistance. The analysis code used in this paper is the soil–water coupled finite deformation analysis code GEOASIA.

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