Shear-wave velocity (Vs) offers a means to determine the seismic resistance of soil to liquefaction by a fundamental soil property. This paper presents the results of an 11-year international project to gather new Vs site data and develop probabilistic correlations for seismic soil liquefaction occurrence. Toward that objective, shear-wave velocity test sites were identified, and measurements made for 301 new liquefaction field case histories in China, Japan, Taiwan, Greece, and the United States over a decade. The majority of these new case histories reoccupy those previously investigated by penetration testing. These new data are combined with previously published case histories to build a global catalog of 422 case histories of Vs liquefaction performance. Bayesian regression and structural reliability methods facilitate a probabilistic treatment of the Vs catalog for performance-based engineering applications. Where possible, uncertainties of the variables comprising both the seismic demand an...

/pdf/shear-wave-velocity-based-probabilistic-and-deterministic-3f4srp88ew.pdf

Shear-Wave Velocity–Based Probabilistic and Deterministic Assessment of Seismic Soil Liquefaction Potential

Downhole arrays are deployed worldwide to record seismic ground response in near-surface strata. The information supplied by these arrays is increasingly becoming the basis for verification, and for development and calibration of predictive tools and design procedures. Advances __ in sensors and information technologies will further expedite this learning process, opening the door for worldwide sharing and collaboration. In this paper, the following topics are addressed: i) A summary of downhole array installations and data in the U.S. and in the Taiwan, Hualien and Lotung sites, ii) An overview of related current research efforts worldwide, iii) Downhole array system identification analyses for lateral and vertical site amplification, iv) Downhole array analyses related to liquefaction and availability of Internet websites for conducting online computations (httd/cvclic.ucsd.edu), and v) Summary of findings, and needs towards future advancements.

/pdf/dynamic-soil-properties-seismic-downhole-arrays-and-1r9g34zj83.pdf

Dynamic Soil Properties, Seismic Downhole Arrays and Applications in Practice

https://www.jstage.jst.go.jp/article/sandf1995/36/Special/36_65/_pdf

Characteristics of ground deformation due to liquefaction

Time-dependent ground motion amplification characteristics at reclaimed land after the 1995 Hyogoken Nambu Earthquake

Underground pipelines are widely applied in the so-called lifeline engineerings. It shows according to seismic surveys that the damage from soil liquefaction to underground pipelines was the most serious, whose failures were mainly in the form of pipeline uplifting. In the present study, dynamic centrifuge model tests were conducted to study the uplifting behaviors of shallow-buried pipeline subjected to seismic vibration in liquefied sites. The uplifting mechanism was discussed through the responses of the pore water pressure and earth pressure around the pipeline. Additionally, the analysis of force, which the pipeline was subjected to before and during vibration, was introduced and proved to be reasonable by the comparison of the measured and the calculated results. The uplifting behavior of pipe is the combination effects of multiple forces, and is highly dependent on the excess pore pressure.

/pdf/uplifting-behavior-of-shallow-buried-pipe-in-liquefiable-2jd31kr4pi.pdf

Uplifting behavior of shallow buried pipe in liquefiable soil by dynamic centrifuge test.

The orientation error of accelrographs in borehole array stations was discussed using the records obtained during the South Hyogo Earthquake of Jan. 17, 1995. The four stations, three of them looted on reclaimed land and the other on stiff ground, were selected The displacement orbits on the horizontal plane were carefully examined, and significant orientation errors were detected The significance of the correction of orientation error was discussed The effective stress-based 2D and/or 3D liquefaction analyses were applied for one of the array stations. It was demonstrated that the method could reproduce the records well in the case that the orientation-corrected base motion was used as the input motion.

Correction of orientation error of borehole strong motion array records obtained during the south hyogo earthquake of jan. 17, 1995

Analysis of strong motion records from the South Hyogo earthquake of January 17, 1995

Designing a offshore pipeline for installation in an area subjected to earthquake activity requires an investigation of potential effects of seismic shocks. If the seabed or the filling material along a pipeline route consists of cohesionless soils likely to liquefy under the influence of seismic shocks, a pipeline buried in such soils may lose stability and float to the surface of the seabed. This paper describes the effectiveness of three types of stabilization techniques, 1) Anchoring the pipeline, 2) Increasing the weight of the pipeline, and 3) New stabilization technique which has been proposed by the authors. In order to simulate the behavior of pipeline under liquefaction, we used finite element model which was proposed by Minami, Kiyomiya and Tsuchida.

https://www.jstage.jst.go.jp/article/jscej1984/1987/380/1987_380_467/_pdf

Numerical study on the effectiveness of stabilization techniques of offshore pipelines against liquefaction

Strong motion records from the Southern Hyogo earthquake of January 17, 1995, are overviewed The discussion is focused on (1) the characteristic of near field records including the predominant direction of motion versus the fault strike and their spectral characteristic, and (2) the orientation error of seismometers and ground motion amplification at borehole array stations Two numerical techniques for seismic response analysis of ground are applied for the array stations The one is the frequency-dependent equi-linearized technique for the frequency domain analysis, and the other is the effective stress-based liquefaction analysis method The numerical calculations are compared with the records at four borehole array stations

Chapter 2 Analysis of strong motion records from the Southern Hyogo earthquake of January 17, 19951

If the ground along an underground pipeline route consists of cohesionless soils likely to liquefy under the influence of seismic shocks, a pipeline buried in such soils may float to the surface of the ground water. In order to investigate the effectiveness of four types of stabilizing techniques of underground pipelines against liquefaction, we performed big size shaking table test. This paper gives a detailed explanation for the observed data and describes the effectiveness of stabilizing techniques.

https://www.jstage.jst.go.jp/article/jscej1984/1987/382/1987_382_175/_pdf

Koji Sekiguchi

Papers

Correction of orientation error of borehole strong motion array records obtained during the south hyogo earthquake of jan. 17, 1995

Analysis of strong motion records from the South Hyogo earthquake of January 17, 1995

Numerical study on the effectiveness of stabilization techniques of offshore pipelines against liquefaction

Chapter 2 Analysis of strong motion records from the Southern Hyogo earthquake of January 17, 19951

Experimental study on the effectiveness of stabilizing techniques of underground pipelines against liquefaction