Interpretation of Penetration Resistance for Back-analysis at Sites of Previous Liquefaction

Liquefaction and paleoliquefaction studies are being used increasingly to interpret ground motion parameters ( i.e. , acceleration distribution, earthquake magnitude, and epicentral location) in regions of the world that experience infrequent, but damaging, earthquakes. These studies are especially applicable when the most recent damaging earthquakes occurred prior to the development of ground-motion instrumentation. For example, Martin and Clough (1994) examined liquefaction features formed during the 1886 Charleston, South Carolina earthquake; Pond (1996) and Obermeier and Pond (1999) examined paleoliquefaction features formed during a number of paleoearthquakes in the Wabash Valley region along the Indiana–Illinois border; Dickenson and Obermeier (1998) and Obermeier and Dickenson (2000) examined paleoliquefaction features formed during the 1700 Cascadia earthquake of the Pacific Northwest; and Ellis and de Alba (1999) recently examined liquefaction features formed during the 1755 Cape Ann, Massachusetts earthquake. Many of these studies back-calculate seismic parameters using the results of penetration tests conducted long after the earthquake. The most common method to back-calculate a lower-bound peak ground surface acceleration is to use the lowest value of penetration resistance obtained at a historic or paleoliquefaction site in conjunction with a correlation for liquefaction resistance of sandy soils, e.g. , Seed et al. (1985) or Stark and Olson (1995). In some studies, the current value of penetration resistance is assumed to be the “representative” value for back-analysis ( e.g. , Pond, 1996), while in other studies corrections are made to the current value of penetration resistance prior to back-analysis ( e.g. , Ellis and de Alba, 1999). This paper examines some of the factors that affect the interpretation of a “representative” penetration resistance for back-analysis of seismic parameters. The interpretation of these factors is illustrated using an example historic liquefaction site. The back-calculated values of a max from the example case history show the sensitivity of the back-analysis …

[1]  I. M. Idriss,et al.  SIMPLIFIED PROCEDURE FOR EVALUATING SOIL LIQUEFACTION POTENTIAL , 1971 .

[2]  Roman D. Hryciw,et al.  A Laboratory Study of Blast Densification of Saturated Sand , 1986 .

[3]  Compaction of alluvial sands by deep blasting , 1984 .

[4]  Issues in Using Liquefaction Features for Paleoseismic Analysis , 1999 .

[5]  P. D. Alba,et al.  Acceleration Distribution and Epicentral Location of the 1755 “Cape Ann” Earthquake from Case Histories of Ground Failure , 1999 .

[6]  Timothy D. Stark,et al.  CPT based liquefaction resistance of sandy soils , 1998 .

[7]  H. Bolton Seed,et al.  Closure of "Soil Liquefaction and Cyclic Mobility Evaluation for Level Ground during Earthquakes" , 1979 .

[8]  John H. Schmertmann,et al.  Discussion of “ Time‐Dependent Strength Gain in Freshly Deposited or Densified Sand ” by James K. Mitchell and Zoltan V. Solymar (November, 1984) , 1987 .

[9]  Kohji Tokimatsu,et al.  EVALUATION OF LIQUEFACTION RESISTANCE OF CLEAN SANDS BASED ON HIGH-QUALITY UNDISTURBED SAMPLES , 1989 .

[10]  Gholamreza Mesri,et al.  Postdensification Penetration Resistance of Clean Sands , 1990 .

[11]  Alec Westley Skempton,et al.  Standard penetration test procedures and the effects in sands of overburden pressure, relative density, particle size, ageing and overconsolidation , 1986 .

[12]  G. W. Clough,et al.  Seismic Parameters from Liquefaction Evidence , 1994 .

[13]  R. D. Hryciw,et al.  Discussion of "Postdensification Penetration Resistance of Clean Sands" , 1992 .

[14]  Timothy D. Stark,et al.  Liquefaction Resistance Using CPT and Field Case Histories , 1995 .

[15]  K. Terzaghi,et al.  Soil mechanics in engineering practice , 1948 .

[16]  W. Baker,et al.  CPT/DMT QC of Ground Modification at a Power Plant , 1986 .

[17]  S. Kramer.  Geotechnical Earthquake Engineering , 1996 .

[18]  John H. Schmertmann,et al.  The Mechanical Aging of Soils , 1991 .

[19]  Riley M. Chung,et al.  Influence of SPT Procedures in Soil Liquefaction Resistance Evaluations , 1985 .

[20]  S. Dickenson,et al.  Liquefaction Evidence for the Strength of Ground Motions Resulting from Late Holocene Cascadia Subduction Earthquakes, with Emphasis on the Event of 1700 A.D. , 2000 .