scholarly journals Experimental evaluation of the effect of soil water fluctuations in the dynamic behavior of machines

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
Marcelo Miranda Cremaschi ◽  
Daniella Escribano Leiva ◽  
Pedro Saavedra González ◽  
Cristián Molina Vicuña
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Physical Model Test ◽  
Soil Parameters ◽  
Foundation Design ◽  
Foundation Soil ◽  
Soil System ◽  
Machine Foundation ◽  
Near Resonance

AbstractIn this study the dynamic response of a machine-foundation-soil system was investigated experimentally and theoretically. The objective of this work is to analyze the effects of the water table fluctuations in the soil on the response of the foundation and machine subjected to dynamic loads at frequencies ranging from 30 to 50 Hz. A physical model test was developed to simulate a machine-foundation-soil system, with measurements of the machine vibrations and the shear wave velocity of the soil. It is found that the water level produced significant changes in the shear wave velocity of the soil and, thus, in the natural frequencies of the system. For a fully saturated soil the vibration levels increased due to a working condition near resonance. The results showed a good agreement between the experimental vibration measurements and the predictions based on the theory used in foundation design, when considering the appropriate soil parameters. It is concluded that proper estimation of soil parameters is of high importance in the design process of machine foundations.

scholarly journals Use of Shear Wave Velocity for Foundation Design

2021 ◽  
Author(s):  
Harry George Poulos
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Small Strain ◽  
Deep Foundations ◽  
Foundation Design ◽  
Suggested Approach ◽  
Load Tests ◽  
Pile Load Tests ◽  
Design Calculations

Abstract This paper describes an approach for utilizing in-situ measurements of shear wave velocity Vs to carry out preliminary and check design calculations for shallow and deep foundations. For estimates of foundation movements, Vs can be used directly to estimate the small-strain stiffness of the soil or rock strata, while for ultimate capacity calculations, use is made of empirical correlations between Vs and penetration resistance measures, which in turn are correlated to the foundation resistance characteristics. The approach is applied to a series of published tests on shallow footings, and on a series of pile load tests for a very tall building. For these cases, comparisons of the calculated with the measured load – settlement behaviour indicates that the suggested approach provides a reasonable, albeit somewhat conservative, level of agreement.

scholarly journals Shear Wave Velocity (Vs) at Reactor Building, Experimental Power Reactor Indonesia

2021 ◽  
Vol 2048 (1) ◽  
pp. 012040
Author(s):  
Eko Rudi Iswanto ◽  
Theo Alvin Ryanto ◽  
Abimanyu BW Setiaji ◽  
Hadi Suntoko
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Power Reactor ◽  
Soil Layer ◽  
Hydrogen Gas ◽  
Design Activity ◽  
Foundation Design ◽  
Site Class ◽  
Reactor Building

Abstract Experimental Power Reactor (RDE) is a Gen IV Reactor type with Hydrogen Gas Cooler. Despite this type of reactor has high safety performance, earthquake hazard should be demonstrated. Detail Engineering Design Activity on RDE has been conducted in the past 3 years. In the end of this phase, preliminary parameter design such as shear wave velocity (Vs) should be defined. This parameter correlated with subsurface condition which has high uncertainty. This study is conducted in order to estimate values of Vs. Generally, the data collection is carried out through geotechnical investigation but this method cost more time and resources. In the recent decades, another method has been widely introduced which is geophysical passive source Microtremor Array Measurement (MAM) with Spatial Auto Correlation (SPAC) method. This method can be used to estimate values of Vs and can be used as preliminary reference to define the position of borehole before construction phase getting started. The result shows, the location of reactor building is estimated to have 5 soil layers with varying Vs value. The Vs value of the first soil layer is about 152 m/s started from the surface to 8 m depth. The second soil layer has 169 m/s Vs value started from 8 m to 20 m depth. The third soil layer, started from 20 m to 36 m depth, has 384 m/s Vs value. The next layer as the fourth layer of soil, started from 36 m to 70 m depth with a value of Vs around 526 m/s. The last soil layer with a depth 70 m to 100 m, has Vs value of 667 m/s. Based on these Vs value estimation from surface to 30 m depth, the average value of the shear wave velocity (Vs 30) is m/s. Thus, reactor building is located in the site class SD with medium soil categories according to SNI 1726-2012. The foundation design and excavation planning phase, this information is needed.

scholarly journals Small strain stiffness in overconsolidated Pliocene clays

2013 ◽  
Vol 45 (2) ◽  
pp. 169-181 ◽  
Author(s):  
Katarzyna Markowska-Lech ◽  
Mariusz Lech ◽  
Marek Bajda ◽  
Alojzy Szymański
Keyword(s):  
Shear Modulus ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Cohesive Soil ◽  
Small Strain ◽  
Soil Parameters ◽  
Small Strain Stiffness ◽  
Triaxial Apparatus ◽  
Triaxial Cell

Abstract Small strain stiffness in overconsolidated Pliocene clays. A huge development of technical infrastructure, including the construction of many high-rise buildings, roads, railroads and extension of subway lines, took place over the recent years in Poland. Therefore, numerous planned investment projects require geotechnical data documenting the variation of soil parameters found in the subsoil. The shear wave velocity is one of the most important input parameters to represent the stiffness of the soil deposits. This paper focuses on the methods and devices using measurements of the shear wave velocity to estimate the initial shear modulus in cohesive soil. It is preferable to measure VS by in situ wave propagation tests, however it is often economically not feasible in all regions of Poland. Hence, a reliable correlation between shear wave velocity and parameters measured in triaxial cell or static penetration parameters would be a considerable advantage. This study shows results obtained from the bender elements tests and field techniques - seismic cone penetration test and seismic flat dilatometer, performed on overconsolidated cohesive soils in Warsaw. On the basis of the test results possible correlations between shear wave velocity (initial shear modulus), mean effective stress and void ratio are considered and four original empirical relationships are proposed. Moreover, the proposed formulas by two different techniques using triaxial apparatus and also RCPT cone were examined. The proposed formulas show a reasonable agreement with direct shear wave velocity profiles for clays and might be incorporated into routine laboratory and field practice

scholarly journals Shear wave velocity by support vector machine based on geotechnical soil properties

2014 ◽  
Vol 2 (4) ◽  
pp. 2443-2461 ◽  
Author(s):  
I. Shooshpasha ◽  
A. Kordnaeij ◽  
U. Dikmen ◽  
H. MolaAbasi ◽  
I. Amir
Keyword(s):  
Support Vector Machine ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Effective Means ◽  
Standard Penetration Test ◽  
Support Vector ◽  
Soil Parameters ◽  
Penetration Test ◽  
In Situ Tests

Abstract. Shear wave velocity (VS) is a basic engineering property implemented in evaluating the soil shear modulus. In many instances it may be preferable to determine VS indirectly by common in-situ tests, such as the Standard Penetration Test (SPT). In this paper, the relationship between VS and geotechnical soil parameters such as standard penetration test blow counts (N160), effective stress and fines content, as well as overburden stress ratio (σvo/σ′vo), is investigated. A new mode based on support vector machine (SVM) approach is proposed to correlate geotechnical parameters and VS, predicated on a total of 620 data sets, including field investigation records for the Kocaeli (Turkey, 1999) and Chi-Chi (Taiwan, 1999) earthquakes. This study addresses the question of whether Support Vector Machine (SVM) approach should be used to estimate VS based on the specified geotechnical variables, and assessing the influence of each variable on VS. Results revealed that SVM, in comparison to previous statistical relations, provides an effective means of efficiently recognizing the patterns in data and accurately predicting the VS.

Study on Critical Shear Wave Velocity of Saturated Loess Foundation Soil Liquefaction under Different Seismic Magnitudes Action

2012 ◽  
Vol 594-597 ◽  
pp. 1720-1726 ◽  
Author(s):  
Ping Wang ◽  
Lan Min Wang ◽  
Qian Wang ◽  
Jun Wang
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Evaluation Method ◽  
Soil Liquefaction ◽  
Test Results ◽  
Foundation Soil ◽  
Liquefaction Potential ◽  
Potential Evaluation ◽  
Loess Region

Use of Seed’s simplified liquefaction evaluation method, combined with the dynamic triaxial test results, and the wave velocity of site liquefaction, to evaluate liquefaction potential of the three typical loess sites under the action of different seismic magnitudes, and calculate the boundary depth of the liquefaction site. Moreover, give the corresponding relationship between the typical loess site liquefaction boundary depth and shear wave velocity, and get the critical shear wave velocity of typical loess liquefaction site. The results of the study show that, (1) saturated loess site could be liquefied under the action of a certain intensity earthquake. (2) saturated soil layers which do not produce liquefied under the action of 6.5 degree earthquake，its critical shear wave velocity is about 200 m/s, and under the action of 7 degree earthquake its critical shear wave velocity is about 303 m/s, under the action of 8 degree earthquake its critical shear wave velocity is about 368 m/s. This conclusion enriches and develops the basis of liquefaction potential evaluation in the loess region.

Multifunctional Piezocone Penetration Testing in Geotechnical Practice

2011 ◽  
Vol 90-93 ◽  
pp. 250-254
Author(s):  
Yan Yong An ◽  
Bao Tian Wang
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Sensor Technology ◽  
Soil Parameters ◽  
Cone Penetration ◽  
Empirical Formulas ◽  
Test Technique ◽  
Penetration Testing ◽  
Porewater Pressure

Cone penetration test is a fast and efficient in-situ test technique. With the development of sensor technology and the use of new probes, such test is employed in more fields and reveals more soil parameters. Based on advanced CPTU equipment, soil types were classified. As CPTU has the function of porewater pressure test, the value of porewater pressure varies a lot when the soil changes, which is shown clearly in the CPTU feature map. So it can be easier to judge soil boundaries and its result is in good agreement with the borehole. Multi-function CPTU system is equip with SCPTU module, which enable to measure shear wave velocity of the soil easily. To meet the needs of conventional CPT equipment, the relationships between shear wave velocity measured by SCPTU and other CPT indexes were analyzed; then, two empirical formulas which suitable for kinds of soils are proved more consistent with the measured results, so it is a good method to estimate shear wave velocity without seismic wave test. With a view to get greater economic and technical benefits, more cone penetration testing experience in different regions should be accumulated for geotechnical engineering investigation and design.

Study on the Correlation between Strength Parameters and Shear Wave Velocity of Pavement Subgrade Soil

2011 ◽  
Vol 90-93 ◽  
pp. 2002-2007
Author(s):  
Guo Yong Cheng ◽  
Xue Juan Liu ◽  
Rui Qiu
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Analytical Models ◽  
Soil Parameters ◽  
Dry Density ◽  
Strength Parameters ◽  
Nondestructive Technique ◽  
Subgrade Soil ◽  
Resilience Modulus

By using three kinds of subgrade soil and controlling dry density and moisture content，the correlation between strength parameters of pavement subgrade soil, California Bearing Ratio(CBR) and Resilience modulus E, and their shear wave velocity are studied through CBR Penetration test, lever pressure meter test and shear wave velocity test. Then the analytical models of CBR and Resilience modulus E by shear wave velocity are proposed. These models are valuable to acquire airport pavement subgrade soil parameters by nondestructive technique.

scholarly journals Improved parameterization to invert Rayleigh-wave data for shallow profiles containing stiff inclusions

Geophysics ◽  
2007 ◽  
Vol 72 (1) ◽  
pp. U1-U10 ◽  
Author(s):  
Carlos Calderón-Macías ◽  
Barbara Luke
Keyword(s):  
Rayleigh Wave ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Reference Model ◽  
A Priori ◽  
Velocity Measurements ◽  
Cost Estimating ◽  
Foundation Design ◽  
Final Model

Inversion of shear-wave velocity profiles from phase-velocity measurements of Rayleigh-wave energy for sites containing stiff layers can be erroneous if such layers are not characterized in the starting or reference model. Incorporation of a priori knowledge then is key for converging upon a realistic or meaningful solution. Resolving soil profiles in desert regions where stiff layers cemented with calcium carbonate are intermixed with softer, uncemented media is an application for which locating shallow stiff inclusions has important implications. Identification of the stiff layers is critical for foundation design and cost estimating of excavations. A parameterization that seems adequate for this problem is to solve for anticipated high-stiffness layers embedded in a coarser (background) profile that captures the general shear-wave velocity trend of the study area. The optimization is accomplished by using simulated annealing. Uncertainty measures resulting from the inversion are helpful for describing the influence of the parameterization on final model estimates.

Corrélations entre des propriétés mécaniques dynamiques et statiques de sols argileux intacts et traités à la chaux

1987 ◽  
Vol 24 (3) ◽  
pp. 327-334 ◽  
Author(s):  
Jacques Locat ◽  
Normand Beauséjour
Keyword(s):  
Shear Strength ◽  
Shear Wave ◽  
Elastic Properties ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Soil Parameters ◽  
Dynamic Shear Modulus ◽  
Static Properties ◽  
Sols Argileux ◽  
Static Mechanical

The use of an ultrasonic accelerometer has led to an empirical correlation between the wave velocity and the static mechanical strength deducted from destructive tests made on intact or lime-treated clays, and to an evaluation of the influence of certain physical soil parameters on wave velocity. The results give a good correlation between the dynamic elastic properties deducted from the shear wave velocity and the static mechanical properties of the intact and the lime-treated clays when measured without confining pressure. The results also confirm that the maximum dynamic shear modulus is proportional to undrained shear strength, independently of soil type. The structure of a lime-treated clay is more favorable to the transmission of shear waves than the same clay in an intact state having the same shear strength; the cause of this difference is associated with the compaction energy and the newly formed minerals resulting from the treatment. Finally, the study of these, treated soils has illustrated the effect of the cementation process on the mechanical behavior of clayey soils. Key words: ultrasonic accelerometer, shear wave velocity, clay, lime treated, cementation, elastic properties, static properties. [Journal translation]

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