Estimating liquefaction-induced ground settlements from CPT for level ground

2002 ◽  
Vol 39 (5) ◽  
pp. 1168-1180 ◽  
Author(s):  
G Zhang ◽  
P K Robertson ◽  
R W.I Brachman
Keyword(s):  
Integrated Approach ◽  
Test Results ◽  
Liquefaction Resistance ◽  
Laboratory Test Results ◽  
Medium Risk ◽  
Major Factors ◽  
Treasure Island ◽  
Silty Soils ◽  
Ground Settlements

An integrated approach to estimate liquefaction-induced ground settlements using CPT data for sites with level ground is presented. The approach combines an existing CPT-based method to estimate liquefaction resistance with laboratory test results on clean sand to evaluate the liquefaction-induced volumetric strains for sandy and silty soils. The proposed method was used to estimate the settlements at both the Marina District and Treasure Island sites damaged by liquefaction during the Loma Prieta, California, earthquake on 17 October 1989. Good agreement between the calculated and measured liquefaction-induced ground settlements was found. The major factors that affect the estimation of liquefaction-induced ground settlements are also discussed in detail. The recommendations for taking the effects of these factors into account in estimating liquefaction-induced ground settlements using the proposed CPT-based approach are presented. It is suggested that the proposed method may be used to estimate liquefaction-induced settlements for low- to medium-risk projects and also to provide preliminary estimates for higher risk projects.Key words: liquefaction, settlements, earthquake, sand, in situ testing.

scholarly journals In-situ Desaturation Tests by Electrolysis for Liquefaction Mitigation

2021 ◽  
Author(s):  
Runze Chen ◽  
Yumin Chen ◽  
Hanlong Liu ◽  
Kunxian Zhang ◽  
Ying Zhou ◽  
...  
Keyword(s):  
Minimum Degree ◽  
Electricity Consumption ◽  
Potential Method ◽  
Economic Benefits ◽  
Degree Of Saturation ◽  
Test Results ◽  
Liquefaction Resistance ◽  
The Difference ◽  
Maximum And Minimum Degree

Electrolytic desaturation is a potential method for improving the liquefaction resistance of the liquefiable foundation by reducing the soil saturation. In this study, in-situ desaturation tests were performed to investigate the resistivity of soil at different depth and the water level of the foundation under different current. The test results show that at constant currents of 1 A (Ampere, unit of the direct current), 2 A and 3 A, the saturation of the treated foundation reached 87%, 83% and 80%. During the electrolysis process, the generated gas migrates vertically and horizontally under the influence of buoyancy and gas pressure. In the end of electrolysis, the gas inside the sand foundation basically migrates vertically only. The higher current intensity employed for electrolysis will affect the uniformity and stability of the gas. At constant currents of 1 A, 2 A and 3 A, the difference between the maximum and minimum degree of saturation in the treated foundation was 14%, 18% and 19%; and after electrolysis halted for 144 h, the saturation in the treated foundation was 90%, 85% and 87%. The electricity consumption analysis indicates that the desaturation method has excellent economic benefits in the treatment of saturated sand foundations.

Effect of cementation on the small-strain parameters of sands

2001 ◽  
Vol 38 (1) ◽  
pp. 191-199 ◽  
Author(s):  
A L Fernandez ◽  
J C Santamarina
Keyword(s):  
Laboratory Test ◽  
Experimental Studies ◽  
Small Strain ◽  
Test Results ◽  
Loading History ◽  
Viscous Losses ◽  
Laboratory Test Results ◽  
Geotechnical Design ◽  
Selection Of

Natural cementation affects the properties of soils, the interpretation of in situ and laboratory test results, and the selection of criteria for geotechnical design. In this paper, published experimental studies are reviewed, a microscale analysis is presented of the effect of cementation on small-strain stiffness for distinct stress-cementation histories, and the effect of cementation on small-strain velocity and damping is experimentally studied. Observations include the prevailing effects of cementation over effective stress, the coexistence of frictional and viscous losses, and the effects of decementation when the medium is unloaded from the level of confinement prevailing during cementation.Key words: wave velocity, seismic response, stiffness, damping, sampling effects, loading history.

A laboratory investigation of the dynamic properties of tailings

2011 ◽  
Vol 48 (11) ◽  
pp. 1587-1600 ◽  
Author(s):  
Michael James ◽  
Michel Aubertin ◽  
Dharma Wijewickreme ◽  
G. Ward Wilson
Keyword(s):  
Dynamic Properties ◽  
Cyclic Stress ◽  
Test Results ◽  
Liquefaction Resistance ◽  
Cyclic Stress Ratio ◽  
Cyclic Resistance ◽  
Direct Simple Shear ◽  
Cyclic Resistance Ratio ◽  
Modulus Reduction

The dynamic response of tailings from a gold mine located in western Quebec was evaluated using cyclic laboratory testing. These tailings are classified as nonplastic silt and sand. Specimens of the tailings were prepared as slurries, consolidated to vertical effective stresses of 100–400 kPa, and subjected to cyclic direct simple shear testing with cyclic stress ratio, CSR, values between 0.075 and 0.15. The shear modulus reduction of the tailings under cyclic loading was found to be fairly similar to that described for clean sands in the literature. The cyclic resistance ratio, CRR (which reflects the liquefaction resistance), of the samples was not significantly affected by the effective consolidation stress (in the range considered here). Analysis of test results with the simplified method of liquefaction evaluation indicates that this method may be applicable to these tailings. However, other factors, such as the possible effects of layering and ageing of the tailings in situ, should also be considered in such an assessment.

In Situ Investigation of Liquefiable Gravels

2000 ◽  
Vol 1714 (1) ◽  
pp. 75-82 ◽  
Author(s):  
Joseph P. Koester ◽  
Chris Daniel ◽  
Michael L. Anderson
Keyword(s):  
Standard Penetration Test ◽  
Lateral Spreading ◽  
Test Results ◽  
Penetration Test ◽  
Liquefaction Resistance ◽  
Testing Procedures ◽  
In Situ Investigation ◽  
Penetration Tests

A series of dynamic in situ penetration tests was performed in deep alluvial gravel deposits at Seward, Alaska, that were shaken and apparently liquefied by the March 27, 1964, Alaska earthquake. Both a U.S. standard penetration test split spoon and a larger-diameter drive sampler were used, and dynamic cone penetrometers of two sizes were also driven into the gravels near the mouth of the Resurrection River that had exhibited settlement and lateral spreading as a result of earthquake shaking. Two safety hammers were used [nominally 623 N (140 lb) and 1334 N (300 lb)], and the energy delivered with various hammer and penetrometer combinations was measured throughout all tests. Limited measurements of hammer velocity were also made by a radar system developed for that purpose to allow for kinetic energy determination. Soils recovered in the split spoon samplers were sent to the U.S. Army Engineer Waterways Experiment Station Soils Research Facility in Vicksburg, Mississippi, where they were evaluated for classification (gradation and index properties). The sampling and testing procedures used at the Seward site, as well as preliminary analysis of the various penetration test results, are summarized. Comparisons are made with penetration resistance measurements made by the Alaska Highway Department immediately after the 1964 earthquake. Results of this investigation will be adapted to guide future practice for in situ determination of liquefaction resistance in coarse alluvial soils.

scholarly journals Study of mining tailings geotechnical parameters obtained from SCPTu tests carried on dry and saturated layers

2021 ◽  
Vol 337 ◽  
pp. 04010
Author(s):  
Helena P. Nierwinski ◽  
Marcelo Heidemann ◽  
Laura A. Lavalle ◽  
Bruna Sell
Keyword(s):  
Laboratory Tests ◽  
Cone Penetration Test ◽  
Test Results ◽  
Penetration Test ◽  
Soil Behavior ◽  
Cone Penetration ◽  
Geotechnical Parameters ◽  
Saturated Layer ◽  
Laboratory Test Results

The correct interpretation of in situ and laboratory test results is an important step in the design of mining tailing containment structures. This study aims to analyze the Seismic Cone Penetration Test (SCPTu) results obtained into a mining tailing reservoir composed of two material layers: a thick-dry and a tick-saturated. It is possible to observe that in a same tailing reservoir, the CPTu test interpretation can lead to a classification of each layer as a different soil with specific behavior and properties. This condition demonstrates that tailings with intermediate permeability (10-5 m/s < k < 10-8 m/s) may present partial drainage conditions during a standard cone penetration test (CPTu) (v=20 mm/s), if saturated conditions are verified. The effects of partial drainage can affect test results, and can induce to errors in the prediction of soil behavior and geotechnical parameters. To evaluate the possible effects of partial drainage, in situ test results were compared to laboratory tests results. It was possible to verify that estimated behavior of dry layers, obtained from in situ tests results, present more similarity to the results from laboratory tests. Probably, the partial drainage effects verified through the interpretation of dissipation tests, distorted the estimated behavior of the saturated layer material.

Mechanical and Mineralogical Characterization of Mortar in Masonry Buildings Damaged by the 20-29th May Earthquake in Emilia

2014 ◽  
Vol 624 ◽  
pp. 379-386 ◽  
Author(s):  
Elisa Galli ◽  
Marco Savoia ◽  
Camilla Colla ◽  
Daniele Ferretti
Keyword(s):  
Chemical Properties ◽  
Test Results ◽  
Flexural Test ◽  
Mineralogical Characterization ◽  
Laboratory Test Results ◽  
Standard Specimens ◽  
Non Destructive ◽  
And Chemical Properties

The aim of the work is to characterize mechanical and chemical properties of the mortar, and thus the masonry, of historical buildings damaged by the Emilia May 20-29th 2012 earthquakes. The attention was focused on historical strategic buildings, located in Modena district. The experimental campaign here reported was carried out for each building through four steps: first, a mechanical characterization of masonry was performed in situ using non-destructive and semi-destructive methods (step 1); then, some materials were collected in order to obtain standard specimens of mortar joint and brick (step 2). In laboratory, those samples were properly prepared for testing (step 3) with compression and flexural test setups; finally, a limited number of those mortar samples were tested in order to obtain their chemical properties (step 4). The in-situ and laboratory test results were separately elaborated for mortar and brick, to characterize the single masonry components. The results were then used to estimate the characteristic masonry parameters. Criteria to obtain the masonry behavior were reviewed in order to give the average masonry parameters. The characteristic and average values of compression strength were compared with ranges provided in the codes for the same masonry typology.

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