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

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.

2005 ◽  
Vol 42 (1) ◽  
pp. 91-109 ◽  
Author(s):  
Yung-Mook Na ◽  
Victor Choa ◽  
Cee-Ing Teh ◽  
Ming-Fang Chang

Sandfill at reclaimed sites is usually formed by more than one placement method. Reclaimed sandfill is often highly variable, and the cone penetration test is most commonly used for site characterization. Correlations among the cone resistance and geotechnical parameters for sand are influenced by the in situ stress level, and it is important to incorporate the stress-level effect. In this study, cone penetration tests were performed at several levels from the top of a 10 m high surcharge, which was later removed step by step, and in situ density was determined layer by layer at the Changi East reclamation site in Singapore. Different ways of normalizing the cone resistance by the corresponding in situ stress were investigated. Specialized in situ tests including the self-boring pressuremeter test, the cone pressure meter test, the seismic cone penetration test, and the plate load test were conducted to provide the reference deformation characteristics of sandfill. Results of the in situ tests indicate that the sand density and the cone resistance profiles vary between areas formed by different sand placement methods. Site-specific correlations developed based on comparison of normalized cone resistance with the reference data obtained from laboratory tests and other in situ tests are found to be suitable for the evaluation of relevant soil parameters.Key words: stress normalization, cone resistance, correlations, geotechnical parameter, in situ characterization, granular soil.


1993 ◽  
Vol 30 (2) ◽  
pp. 211-219 ◽  
Author(s):  
W. P. Stewart ◽  
R. G. Campanella

The downhole seismic cone penetration test (SCPT) procedure has been extended to allow the measurement of material damping at small strains at minimum expense while one is measuring shear wave velocity. The nature of damping, the required equipment characteristics, and the recommended procedure and calculation methodology are presented in a practical way. SCPT results from four different sites give results that are in general agreement with laboratory measurements of damping for sands and clays and with values recommended by other authors. It appears, however, that previously reported measurements of damping by borehole methods are higher, by a factor of two or more, when compared with SCPT and laboratory results. Key words : in situ, damping, seismic, shear wave, cone penetrometers, procedures.


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.


Author(s):  
Abdulrahman M. Hamid ◽  
Saad A. Aiban ◽  
Omar S. Baghabra Al-Amoudi

Rapid and accurate in-situ measurement of soil properties is still a challenge facing the construction industry and there is a need for new and advanced devices and methods. Dynamic cone penetration test (DCPT) is an effective device used for field exploration and quality assessment of subsoil. DCPT could be used to predict the engineering properties of sand because it is difficult to perform conventional density tests, such as the sand replacement method, especially when loose or submerged sandy soil is encountered. Two cases of DCP field testing were conducted in Al-Jubail and Ras Al-Khair, eastern Saudi Arabia, where the major petrochemical industries are located. These tests were utilized to evaluate the potential use of DCPT to assess the density during the construction of backfills, whereby the nuclear gauge was also used to accurately measure the in situ soil density and water content. The DCP-nuclear gauge data clearly indicated that there is a good correlation between the dry density obtained from the nuclear gauge and the dynamic cone penetration (DCP) readings, which proves that the DCPT is an effective and reliable tool in the assessment of in situ compaction of sand backfills.


1990 ◽  
Vol 27 (1) ◽  
pp. 151-158 ◽  
Author(s):  
P. K. Robertson

Several charts exist for evaluating soil type from electric cone penetration test (CPT) data. A new system is proposed based on normalized CPT data. The new charts are based on extensive data available from published and unpublished experience worldwide. The new charts are evaluated using data from a 300 m deep borehole with wire-line CPT. Good agreement was obtained between samples and the CPT data using the new normalized charts. Recommendations are provided concerning the location at which to measure pore pressures during cone penetration. Key words: soil classification, cone penetration test, in situ, case history.


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