scholarly journals Evaluating the Geotechnical and Geophysical Characteristics of Expanding Districts in Tehran Using Field Experiments

2018 ◽  
Vol 4 (2) ◽  
pp. 363
Author(s):  
Arash Razmyar ◽  
Abolfazl Eslami
Keyword(s):  
Urban Areas ◽  
Field Experiments ◽  
Geophysical Methods ◽  
Field Tests ◽  
Young Modulus ◽  
Friction Angle ◽  
Standard Penetration Test ◽  
Penetration Test ◽  
Engineering Structures ◽  
Geotechnical Characteristics

Considering the increasing population growth and the rapid growth of urbanization and pollution in the environment, providing zoning maps and urban engineering geology seem to be important. The rapid construction growth of cities, as well as the confrontation with events such as earthquakes and failure to observe the geological and geotechnical issues, has caused many engineering problems. The use of geophysical methods not only cannot lonely provide us a complete and comprehensive information on the geotechnical conditions of the earth but also has many disturbances in urban areas, and its use in urban centers is almost impractical. Therefore, it seems that the best way of examining and interpreting the geotechnical characteristics of a site, especially in urban areas, is the use of suspicious data. Therefore, performing geotechnical studies and geotechnical zoning can be useful for retrofitting buildings and engineering structures and reducing their risks. Hence, zoning studies are conducted in this research in order to better recognize the technical soil status for safe construction due to rising the population of Tehran in recent decades and the concentration of population in certain areas of Tehran, especially in the eastern and western regions (districts 4 and 22). In this study, different geotechnical field tests such as standard penetration test (SPT), cone penetration test (CPT) were used to estimate parameters such as adhesion coefficient (C), internal friction angle ( ), Young modulus (E). Other common experiments with conventional geophysical experiments, such as in good experiments, refractive and CSSW were applied to estimate geophysical parameters of bedrock depth and shear wave velocity for zoning these areas.

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.

scholarly journals COMPARISON BETWEEN RESULTS OF SEISMIC REFRACTION AND STANDARD PENETRATION TEST (SPT) TO STUDY SHALLOW GEOLOGICAL SUBSURFACE IN AN URBAN AREA OF BRASÍLIA, BRAZIL

2014 ◽  
Vol 32 (4) ◽  
pp. 673
Author(s):  
Pedro Vencovsky Nogueira ◽  
Marcelo Peres Rocha ◽  
Welitom Rodrigues Borges ◽  
Eduardo Xavier Seimetz ◽  
Márcio Maciel Cavalcanti
Keyword(s):  
Low Cost ◽  
Seismic Refraction ◽  
Geophysical Methods ◽  
Standard Penetration Test ◽  
P Wave ◽  
Penetration Test ◽  
Engineering Project ◽  
Common Procedure ◽  
Shallow Seismic ◽  
Investigation Methods

ABSTRACT. The most common procedure for an engineering project/construction is the use of direct survey, borehole and Standard Penetration Test (SPT). Thisprovides punctual information of the geology at the site, and many boreholes are necessary along the construction site, representing a significant amount of the budgetfor the construction and to help develop a better geological understand/map of the site. The use of geophysical methods allows to study the subsurface by indirectmeans, with low cost, and enable to cover large areas if compared to direct surveys. Geophysical methods are increasingly being used in engineering works, however, inBrazil the use in engineering projects is still scarce. In this work was used shallow seismic refraction method to study the shallow subsurface in an area along the futuretrack of the subway system of Bras´ılia, Brazil. The refraction results (P-wave) were compared with previous existing data from Standard Penetration Test (SPT), and soilprofile description. The seismic was used to study the subsurface geology, and SPT data were used to compare the seismic results. We observed a good correlationfor the depths obtained through each method, mostly in the north portion of the line, when the SPT was near the line, indicating that its results are influenced by thesame mechanical parameters, related to soil strength. Our results motivate the use of seismic refraction as a tool to optimize the direct investigation methods for bettergeotechnical characterization of the medium.Keywords: shallow seismic refraction, standard penetration test (SPT), geotechnical study. RESUMO. O procedimento inicial mais comum em um projeto de engenharia é o uso de pesquisa direta, por meio de sondagens e Índice de Resistência à Penetração (SPT, em inglês). Estas ferramentas fornecem informações pontuais acerca da geologia local, sendo necessárias diversas sondagens para desenvolver um bom entendimento geológico/geotécnico da região, fazendo com que as sondagens representem uma quantidade significativa do orçamento da obra de engenharia. O usode métodos geofísicos permite estudar a subsuperfície por meio indireto, com baixo custo, e possibilita cobrir grandes áreas, quando comparado ao uso exclusivo desondagens diretas. Métodos geofísicos estão sendo cada vez mais utilizados em obras de engenharia, no entanto, o seu uso em projetos de engenharia no Brasil aindaé escasso. Neste trabalho foi utilizado o método de sísmica de refração rasa para estudar a subsuperfície em uma área ao longo do futuro trecho do sistema de metrô de Brasília, Brasil. Os resultados de refração (onda P) foram comparados com os dados pré-existentes de SPT e descrição do solo. A sísmica foi empregada para estudara geologia da subsuperfície, os dados SPT foram utilizados para comparar com os resultados sísmicos. Observou-se uma boa correlação para as profundezas obtidas através de cada método, principalmente na porção norte da linha, região em que o SPT está mais próximo da linha, indicando que os seus resultados são influenciados pelos mesmos parâmetros mecânicos, relacionados com a resistência do solo. Nossos resultados motivam o uso de refração sísmica como uma ferramenta para aperfeiçoar os métodos de investigação direta, com objetivo de gerar uma melhor caracterização geotécnica do meio.Palavras-chave: sísmica de refração rasa, índice de resistência à penetração, estudo geotécnico.

scholarly journals Energy Ratio (ER) for the Standard Penetration Test Based on Measured Field Tests

2017 ◽  
Vol 40 (2) ◽  
pp. 77-91
Author(s):  
Juliana Azoia Lukiantchuki ◽  
George de Paula Bernardes ◽  
Edmundo Rogerio Esquivel
Keyword(s):  
Field Tests ◽  
Standard Penetration Test ◽  
Energy Ratio ◽  
Penetration Test ◽  
Measured Field

scholarly journals Assessment of liquefaction-induced hazards using Bayesian networks based on standard penetration test data

2018 ◽  
Vol 18 (5) ◽  
pp. 1451-1468 ◽  
Author(s):  
Xiao-Wei Tang ◽  
Xu Bai ◽  
Ji-Lei Hu ◽  
Jiang-Nan Qiu
Keyword(s):  
Bayesian Networks ◽  
Test Data ◽  
Standard Penetration Test ◽  
Lateral Spreading ◽  
Brier Score ◽  
Penetration Test ◽  
Damage State ◽  
Engineering Structures ◽  
Seismic Liquefaction ◽  
Sand Boils

Abstract. Liquefaction-induced hazards such as sand boils, ground cracks, settlement, and lateral spreading are responsible for considerable damage to engineering structures during major earthquakes. Presently, there is no effective empirical approach that can assess different liquefaction-induced hazards in one model. This is because of the uncertainties and complexity of the factors related to seismic liquefaction and liquefaction-induced hazards. In this study, Bayesian networks (BNs) are used to integrate multiple factors related to seismic liquefaction, sand boils, ground cracks, settlement, and lateral spreading into a model based on standard penetration test data. The constructed BN model can assess four different liquefaction-induced hazards together. In a case study, the BN method outperforms an artificial neural network and Ishihara and Yoshimine's simplified method in terms of accuracy, Brier score, recall, precision, and area under the curve (AUC) of the receiver operating characteristic (ROC). This demonstrates that the BN method is a good alternative tool for the risk assessment of liquefaction-induced hazards. Furthermore, the performance of the BN model in estimating liquefaction-induced hazards in Japan's 2011 Tōhoku earthquake confirms its correctness and reliability compared with the liquefaction potential index approach. The proposed BN model can also predict whether the soil becomes liquefied after an earthquake and can deduce the chain reaction process of liquefaction-induced hazards and perform backward reasoning. The assessment results from the proposed model provide informative guidelines for decision-makers to detect the damage state of a field following liquefaction.

Correlation between standard penetration test values and overburden pressure for desert sands

1988 ◽  
Vol 25 (3) ◽  
pp. 590-594 ◽  
Author(s):  
Nabil F. Ismael ◽  
A. M. Jeragh ◽  
O. A. Khalidi ◽  
M. A. Mollah
Keyword(s):  
Calcareous Soils ◽  
Field Tests ◽  
Field Testing ◽  
Standard Penetration Test ◽  
Testing Procedure ◽  
Silica Sand ◽  
Correction Factors ◽  
Penetration Test ◽  
Overburden Pressure ◽  
Pressure Standard

The influence of the effective overburden pressure on the standard penetration test (SPT) values in calcareous desert sands is examined by field tests. A simple field testing procedure is proposed and employed in Kuwait at five sites having different relative densities for the surface soils. The correction factors for the SPT are determined from test results and compared with the most reliable correlations for clean silica sand. Key words: field tests, plate bearing tests, overburden pressure, standard penetration test, correction factors, relative density, calcareous soils, shear strength, compressibility.

scholarly journals PERBANDINGAN DAYA DUKUNG TIANG PANCANG BERDASARKAN PENGUJIAN CONE PENETRATION TEST (CPT) DAN STANDARD PENETRATION TEST (SPT) PADA TANAH BERPASIR

UKaRsT ◽  
2020 ◽  
Vol 4 (1) ◽  
pp. 109
Author(s):  
I Wayan Ariyana Basoka
Keyword(s):  
Bearing Capacity ◽  
Field Tests ◽  
Field Testing ◽  
Cone Penetration Test ◽  
Standard Penetration Test ◽  
Pile Foundations ◽  
Capacity Analysis ◽  
Penetration Test ◽  
Cone Penetration ◽  
Spt Data

Design of building structure always related to the foundation, field testing is often done to test the bearing capacity of the soil in the form of a cone penetration test (CPT) and a standard penetration test (SPT). From the two field tests that are often done, it is necessary to research the amount of bearing capacity obtained through CPT and SPT data. This study uses a bearing capacity analysis of the pile foundation using CPT and SPT data in Pesanggaran, Bali, Indonesia. The analysis was carried out by comparing the bearing capacity of pile foundations using pile foundations with dimensions of 15 cm, 20 cm, 25 cm and 30 cm at a level of 10 meters. The results of the bearing capacity percentage are then compared. From the analysis conducted, the bearing capacity of pile foundations using CPT data has a higher value than the carrying capacity of poles using SPT data with a bearing capacity difference of 10,4-16,3%.Perancangan suatu struktur erat kaitannya dengan fondasi, pengujian lapangan yang sering dilakukan untuk mengetahui daya dukung fondasi berupa cone penetration test (CPT) dan standard penetration test (SPT). Dari dua pengujian lapangan yang sering dilakukan, maka perlu dilakukan dilakukan penelitian mengenai seberapa besar perbedaan hasil daya dukung yang diperoleh melalui data CPT dan SPT. Penelitian ini melakukan perbandingan analisis daya dukung fondasi tiang dengan menggunakan data CPT dan SPT di Pesanggaran, Bali, Indonesia. Analisis dilakukan dengan membandingkan daya dukung fondasi tiang menggunakan fondasi tiang berdimensi 15 cm, 20 cm, 25 cm, dan 30 cm pada kedalaman 10 meter. Hasil persentase daya dukung yang diperoleh kemudian dibandingkan. Dari analisis yang dilakukan, diperoleh daya dukung fondasi tiang menggunakan data CPT memiliki nilai lebih tinggi daripada daya dukung tiang menggunakan data SPT dengan perbedaan daya dukung 10,4-16,3%.

Static cone tests and settlement of calcareous desert sands

1986 ◽  
Vol 23 (3) ◽  
pp. 297-303 ◽  
Author(s):  
Nabil F. Ismael ◽  
Abdul Majeed Jeragh
Keyword(s):  
Ground Surface ◽  
Field Tests ◽  
Standard Penetration Test ◽  
Penetration Test ◽  
Cone Penetration ◽  
Soil Pressure ◽  
Cone Penetration Tests ◽  
Below Ground ◽  
Load Tests ◽  
Penetration Tests

The results of a recent in situ testing program to establish standard penetration test – cone penetration test (SPT–CPT) correlation for the windblown calcareous desert sands of Kuwait are presented and analyzed. The program consisted of auger borings and static cone tests at five sites along a 35 km long corridor. The resulting correlation was employed for prediction of the allowable soil pressure of footings at seven sites in Kuwait where load tests were carried out on square concrete footings placed at a depth of 1 m below ground surface. A comparison of the measured to the predicted soil pressures using the Schmertmann method indicated very close agreement. The average ratio of measured to predicted soil pressure is 93% for the seven test sites. Recommendations are made for further testing to determine the long-term settlement components due to creep and cyclic loading. Key words: load tests, sands, footings, allowable pressure, settlement, field tests, borings, cone penetration tests.

The Effects of Vertical Stress on the Liquefaction Potential Originated from Buildings in The Urban Areas

2017 ◽  
Vol 8 (1) ◽  
pp. 38-57
Author(s):  
Mehmet Ozcelik
Keyword(s):  
Urban Areas ◽  
Standard Penetration Test ◽  
Soil Liquefaction ◽  
Vertical Stress ◽  
Limited Information ◽  
Penetration Test ◽  
Liquefaction Potential ◽  
Empirical Procedure ◽  
Seismic Forces

Main purpose of this paper is to study the influence of vertical stress on soil liquefaction in urban areas. The literature provides limited information on vertical stress analysis of multiple footings, and, as a result, there is no accurate way to account for the effect of the foundation depth on liquefaction. Additionally, practical methods do not exist for considering the interaction between the neighboring foundations vertical stress and seismic forces in the urban area. Vertical stress distribution was calculated in examining the soil liquefaction potential exhibited by building foundations as a case study. The vertical stresses were chosen randomly for some buildings with foundation depths of 3.00 m; 4.50 and 6.00 m at the Burkent site (Burdur-Turkey). The influence of 5-storey buildings on the liquefaction potential of sandy soils was evaluated in terms of the safety factor (FS) against liquefaction along soil profile depths for different earthquakes. Standard Penetration Test (SPT) results were used based on simplified empirical procedure.

scholarly journals Identification, Monitoring, and Assessment of an Active Landslide in Tavan-Hauthao, Sapa, Laocai, Vietnam – A Multidisciplinary Approach

2021 ◽  
Vol 16 (4) ◽  
pp. 501-511
Author(s):  
Manh Duc Nguyen ◽  
Nguyen Van Thang ◽  
Akihiko Wakai ◽  
Go Sato ◽  
Jessada Karnjana ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Geophysical Methods ◽  
Standard Penetration Test ◽  
The Road ◽  
Geotechnical Characteristics ◽  
Ground Survey ◽  
Geotechnical Investigations ◽  
Active Landslide ◽  
Ancient Rock ◽  
Geologic Condition

The active landslide located in the Tavan-Hauthao, Sapa district, Laocai province, Vietnam was investigated using geophysical methods (2D Electrical Resistivity and Tomography), geotechnical investigations, and a ground survey to assess the geologic condition of the sliding block and surrounding ground. Landslide displacement was measured using 15 surface monitoring points. Numerical modeling was done to assess the behavior of an active landslide. This multi-disciplinary approach helped in interpreting landslide stratigraphy, geotechnical characteristics of the sliding groundmass, depth, and nature of the sliding plane. The surface area of the slide is approximately 1200 m2. Studying this active landslide is important as it affects the road No. 152, which is an important road connecting the Sapa Ancient Rock Field. This study involved surface topographical survey, surface and sub-surface geological, and geotechnical investigations including Standard Penetration Test and Electrical Resistivity Tomography. Geologic and geotechnical data were used to characterize an active landslide block, which is composed of different soil layers underlaid by granitic rock. The surface electrical-resistivity measurements across the Sapa landslide resulted in inverted-resistivity sections with distinct resistivity contrasts that correlated well with the geology and geo-hydrology observed in boreholes.

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