In Situ State of Tailing Silts Using a Numerical Model of Piezocone Penetration Test Developed by Norsand Model

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
A. Pezeshki ◽  
M. M. Ahmadi
Keyword(s):  
Numerical Model ◽  
Penetration Test ◽  
Piezocone Penetration Test

scholarly journals Characterization on the correlation between SPT-N and small strain shear modulus Gmax of Jiangsu silts of China

2021 ◽  
Vol 25 (2) ◽  
pp. 225-235
Author(s):  
Ya Chu ◽  
Songyu Liu ◽  
Guojun Cai
Keyword(s):  
Shear Modulus ◽  
Soil Layer ◽  
Small Strain ◽  
Penetration Test ◽  
Undisturbed Soil ◽  
Improvement Project ◽  
Small Strain Shear Modulus ◽  
Piezocone Penetration Test ◽  
Regression Relations

Small strain shear modulus plays a fundamental role in the evaluation of site response parameters. Only few authors used measured density and shear wave velocity (Vs) to estimate small strain shear modulus. In this study, an attempt has been made to develop the regression relationship between standard penetration test (SPT) N values and the small strain shear modulus (Gmax). For this purpose, field investigations SPT and seismic piezocone penetration test (SCPTU) data from locations in Su-Xin Expressway of China, have been used, which were also used for ground improvement project. The in situ density of soil layer was estimated using undisturbed soil samples from the boreholes. The Vs profiles with depth were obtained for the locations close to the boreholes. The values for small strain shear modulus have been calculated by measured Vs and in situ soil density. About 50 pairs of SPT-N and Gmax values were used for regression analysis. The differences between measured and corrected values which were used in fitted regression relations were analyzed. Most of the existing correlations were developed based on the studies carried out in Japan and in India, where N values are measured with hammer energy of 78%, which may not be directly applicable for other regions because of the variation in SPT hammer energy which in China is about 55%. A new correlation has been generated using the measured values in silts of China. From this study, it is found that uncorrected values of N and modulus gives the best fit regression relations when compared to corrected N and corrected modulus values. With most equation was used for sand and clay, the regression relations between corrected values of N and modulus gives the equation of silts in China.

Piezocone dissipation tests at the Canadian Test Site No. 1, Gloucester, Ontario

2016 ◽  
Vol 53 (5) ◽  
pp. 884-888 ◽  
Author(s):  
Will McQueen ◽  
Bruce Miller ◽  
Paul W. Mayne ◽  
Shehab Agaiby
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Test Site ◽  
Penetration Test ◽  
Piezocone Penetration Test ◽  
Dilatory Response ◽  
The Individual

A series of pore-water pressure dissipation records were acquired using a type 2 piezocone penetrometer sounding that was performed in the sensitive Leda clays underlying the Canadian Geotechnical Research site in South Gloucester, Ontario. This note presents the results of the piezocone penetration test (CPTu) sounding and the individual pore-water pressure decays with time that were measured at 1 m vertical intervals, ranging from depths of 2 to 23 m at the site. Using soil behavioral charts, the sounding confirmed the presence of soft sensitive clays. While many of the dissipations were predominantly monotonic, some dilatory response was also observed at shallow depths. Thus, a grouping of dissipatory behaviors was used to infer layers of similar clay characteristics. The results are offered as complementary data to existing in situ and laboratory information that have been collected at this important experimental test site.

scholarly journals The Application of Piezocone Penetration Test (CPTU) in Water Area Hydrogeological Investigation

2021 ◽  
Vol 236 ◽  
pp. 01039
Author(s):  
Xueying Gu ◽  
Yukun Jiang ◽  
Lihong Zhou
Keyword(s):  
The Netherlands ◽  
Pore Pressure ◽  
Water Area ◽  
Structure Design ◽  
Penetration Test ◽  
Test Device ◽  
Piezocone Penetration Test ◽  
Successful Solution ◽  
Hydrogeological Investigation

Piezocone penetration test device imported from the Netherlands was used to conduct pore pressure dissipation tests at 4 measuring points in 2 holes in the water area of Sutong GIL utility tunnel project. After dissipation, stable pore pressure was used to analyse groundwater pressure and further obtain the height of groundwater head. This method provides a successful solution for in-situ stratification testing of groundwater parameters in water area engineering, and provides reliable hydrologic parameters such as groundwater pressure for structure design and construction

Reliability of Piezocone Penetration Test Methods for Estimating the Coefficient of Consolidation of Cohesive Soils

2005 ◽  
Vol 1913 (1) ◽  
pp. 62-76 ◽  
Author(s):  
Murad Y. Abu-Farsakh ◽  
Munir D. Nazzal
Keyword(s):  
Test Methods ◽  
Cohesive Soils ◽  
Penetration Test ◽  
Coefficient Of Consolidation ◽  
Piezocone Penetration Test ◽  
Cone Tip Resistance ◽  
Tip Resistance ◽  
Penetration Depths ◽  
Better Than

The current piezocone penetration test (PCPT) interpretation methods were evaluated for their capability to estimate the vertical coefficient of consolidation (c v) of cohesive soils reasonably by using the piezocone dissipation tests. Seven PCPT methods were evaluated. Six sites in Louisiana were selected for this study. At each site, in situ PCPT tests were performed, and soundings of cone tip resistance, sleeve friction, and pore pressures at different locations were recorded. Piezocone dissipation tests also were conducted at different penetration depths. High-quality Shelby tube samples were collected close to the PCPT tests and were used to carry out a comprehensive laboratory testing program. The (c v) values predicted by the different interpretation methods were compared with the reference values determined from the oedometer laboratory tests. The results of this study showed that two methods can estimate cv better than the other prediction methods.

scholarly journals Effects of Infills in the Seismic Performance of an RC Factory Building in Pakistan

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 276
Author(s):  
Nisar Ali Khan ◽  
Giorgio Monti ◽  
Camillo Nuti ◽  
Marco Vailati
Keyword(s):  
Numerical Model ◽  
Construction Materials ◽  
Building Codes ◽  
Construction Technique ◽  
Infill Walls ◽  
Mortar Strength ◽  
Materials Used ◽  
Seismic Response Of Buildings

Infilled reinforced concrete (IRC) frames are a very common construction typology, not only in developing countries such as Pakistan but also in southern Europe and Western countries, due to their ease of construction and less technical skills required for the construction. Their performance during past earthquakes has been in some cases satisfactory and in other cases inadequate. Significant effort has been made among researchers to improve such performance, but few have highlighted the influence of construction materials used in the infill walls. In some building codes, infills are still considered as non-structural elements, both in the design of new buildings and, sometimes, in the assessment of existing buildings. This is mainly due to some difficulties in modeling their mechanical behavior and also the large variety of typologies, which are difficult to categorize. Some building codes, for example, Eurocode, already address the influence of infill walls in design, but there is still a lack of homogeneity among different codes. For example, the Pakistan building code (PBC) does not address infills, despite being a common construction technique in the country. Past earthquake survey records show that construction materials and infill types significantly affect the seismic response of buildings, thus highlighting the importance of investigating such parameters. This is the object of this work, where a numerical model for infill walls is introduced, which aims at predicting their failure mode, as a function of some essential parameters, such as the friction coefficient between mortar and brick surface and mortar strength, usually disregarded in previous models. A comprehensive case study is presented of a three-story IRC frame located in the city of Mirpur, Pakistan, hit by an earthquake of magnitude 5.9 on 24 September 2019. The results obtained from the numerical model show good agreement with the damage patterns observed in situ, thus highlighting the importance of correctly modeling the infill walls when seismically designing or assessing Pakistani buildings that make use of this technology.

Application of Neural Network in Identifying Soil Strata by CPT or CPTU Data

2012 ◽  
Vol 170-173 ◽  
pp. 945-949
Author(s):  
Jun Hai Li
Keyword(s):  
Neural Network ◽  
Ground Improvement ◽  
Thin Layers ◽  
Slope Instability ◽  
General Regression Neural Network ◽  
Excess Pore Pressure ◽  
Soil Conditions ◽  
Penetration Test ◽  
Piezocone Penetration Test ◽  
Tip Resistance

In geotechnical engineering, assessment of the depth location of stratigraphic interfaces and the depth and thickness of thin layers can be critical in the design process. For example, stratigraphic interfaces can promote anisotropic soil strength response and potentially provide preferential slip planes that create slope instability. Similarly, the presence of thin, high permeability layers can alter groundwater flow regimes and rates of consolidation, which can hinder or accelerate methods of ground improvement. The piezocone penetration test (PCPT or CPTU) is an extension of the cone penetration test (CPT) and is able to measure cone tip resistance, sleeve friction and generated pore-water pressures simultaneously. The piezocone’s functionality is through the measured excess pore pressure profile, which reflects changes in the drainage conditions, and therefore soil conditions. In this paper the relationship between CPTU parameters and soil types and strata is analyzed, and the structure of a general regression neural network (GRNN) is designed, and the application program is programmed with MATLAB language. The results, identifying soil strata by CPTU, have confirmed that GRNN can be used to carry out the automatically identifying soil strata.

Assessment of the range of variation of Nγ from 60 estimation methods for footings on sand

2013 ◽  
Vol 50 (7) ◽  
pp. 793-800 ◽  
Author(s):  
Edgar Giovanny Diaz-Segura
Keyword(s):  
Friction Angle ◽  
Standard Penetration Test ◽  
Estimation Methods ◽  
Penetration Test ◽  
In Situ Tests ◽  
Vertical Loading ◽  
Simplified Method ◽  
Bearing Capacity Factor ◽  
Range Of Variation

The range of variation of the bearing capacity factor, Nγ, was assessed using 60 estimation methods for rough footings on sand subjected to static vertical loading. The influence on the Nγ values of the use of correlations for the estimation of the friction angle, [Formula: see text], derived from in situ tests was also assessed. The analysis shows a marked dependency on the methods used to determine Nγ, showing differences for the same [Formula: see text] values of up to 267% between estimated values. Uncertainty in the estimation of [Formula: see text], due to the use of correlations with in situ tests, leads to a range of variation for Nγ higher than that seen using the 60 estimation methods. Finally, given the regular use of the in situ standard penetration test (SPT) on sands, and based on a series of analyses using finite elements, a simplified method in terms of the SPT N-values is proposed for estimation of Nγ in footings on sands.

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