Investigations of andesitic volcanic debris terrains: Part 2 — Geotechnical

Geophysics ◽  
2006 ◽  
Vol 71 (1) ◽  
pp. B9-B15 ◽  
Author(s):  
Derek A. Gay ◽  
Frank D. Morgan ◽  
Yervant Vichabian ◽  
John A. Sogade ◽  
Philip Reppert ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Elastic Moduli ◽  
Seismic Velocity ◽  
Dynamic Elastic Modulus ◽  
Geotechnical Investigation ◽  
Geophysical Investigation ◽  
Geotechnical Investigations ◽  
Dynamic Elastic Moduli ◽  
Volcanic Debris ◽  
Data Correlations

Here, results of geotechnical investigations for the proposed Dominica international airport are presented. The main geotechnical investigative method is comprised of boreholes to 30 m depth with standard penetrating testing (SPT) and undisturbed Shelby tube and disturbed split-spoon soil sampling. The geotechnical investigation confirms the findings of a companion geophysical investigation, which concludes that bedrock is not likely to be encountered within the proposed depths of excavation for the airport. Geophysical and geotechnical data correlations are developed. Seismic velocity and the number N of blow counts with SPT (SPT N) appear to be well correlated by a linear model. A model relationship between SPT and seismic dynamic elastic modulus is developed using seismic velocity. SPT N is better correlated with the dynamic elastic modulus than with seismic velocity. The study shows that the seismic velocity and the derived dynamic elastic moduli can accurately predict soil strength as measured by SPT blow counts.

scholarly journals Comparison of elastic moduli from seismic diving-wave and ice-core microstructure analysis in Antarctic polar firn

2019 ◽  
Vol 60 (79) ◽  
pp. 220-230 ◽  
Author(s):  
Rebecca Schlegel ◽  
Anja Diez ◽  
Henning Löwe ◽  
Christoph Mayer ◽  
Astrid Lambrecht ◽  
...  
Keyword(s):  
Elastic Moduli ◽  
Seismic Velocity ◽  
Ice Core ◽  
S Wave ◽  
Uncertainty Range ◽  
Wave Refraction ◽  
Refraction Seismic ◽  
Dynamic Elastic Moduli ◽  
Static Elastic Moduli ◽  
Firn Core

ABSTRACTWe compared elastic moduli in polar firn derived from diving wave refraction seismic velocity analysis, firn-core density measurements and microstructure modelling based on firn-core data. The seismic data were obtained with a small electrodynamic vibrator source near Kohnen Station, East Antarctica. The analysis of diving waves resulted in velocity–depth profiles for different wave types (P-, SH- and SV-waves). Dynamic elastic moduli of firn were derived by combining P- and S-wave velocities and densities obtained from firn-core measurements. The structural finite-element method (FEM) was used to calculate the components of the elastic tensor from firn microstructure derived from X-ray tomography of firn-core samples at depths of 10, 42, 71 and 99 m, providing static elastic moduli. Shear and bulk moduli range from 0.39 to 2.42 GPa and 0.68 to 2.42 GPa, respectively. The elastic moduli from seismic observations and the structural FEM agree within 8.5% for the deepest achieved values at a depth of 71 m, and are within the uncertainty range. Our observations demonstrate that the elastic moduli of the firn can be consistently obtained from two independent methods which are based on dynamic (seismic) and static (tomography and FEM) observations, respectively, for deeper layers in the firn below ~10 m depth.

scholarly journals Evaluation of Static and Dynamic Residual Mechanical Properties of Heat-Damaged Concrete for Nuclear Reactor Auxiliary Buildings in Korea Using Elastic Wave Velocity Measurements

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2695 ◽  
Author(s):  
Seong-Hoon Kee ◽  
Jun Won Kang ◽  
Byong-Jeong Choi ◽  
Juho Kwon ◽  
Ma. Doreen Candelaria
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Elastic Wave ◽  
Wave Velocity ◽  
Elastic Moduli ◽  
Nuclear Reactor ◽  
Dynamic Properties ◽  
Velocity Measurements ◽  
Heating And Cooling ◽  
Dynamic Elastic Moduli

The main objectives of this study are (1) to investigate the effects of heating and cooling on the static and dynamic residual properties of 35 MPa (5000 psi) concrete used in the design and construction of nuclear reactor auxiliary buildings in Korea; and (2) to establish the correlation between static and dynamic properties of heat-damaged concrete. For these purposes, concrete specimens (100 mm × 200 mm cylinder) were fabricated in a batch plant at a nuclear power plant (NPP) construction site in Korea. To induce thermal damages, the concrete specimens were heated to target temperatures from 100 °C to 1000 °C with intervals of 100 °C, at a heating rate of 5 °C/min and allowed to reach room temperature by natural cooling. The dynamic properties (dynamic elastic modulus and dynamic Poisson’s ratio) of concrete were evaluated using elastic wave measurements (P-wave velocity measurements according to ASTM C597/C597M-16 and fundamental longitudinal and transverse resonance tests according to ASTM C215-14) before and after the thermal damages. The static properties (compressive strength, static elastic modulus and static Poisson’s ratio) of heat-damaged concrete were measured by the uniaxial compressive testing in accordance with ASTM C39-14 and ASTM C469-14. It was demonstrated that the elastic wave velocities of heat-damaged concrete were proportional to the square root of the reduced dynamic elastic moduli. Furthermore, the relationship between static and dynamic elastic moduli of heat-damaged concrete was established in this study. The results of this study could improve the understanding of the static and dynamic residual mechanical properties of Korea NPP concrete under heating and cooling.

scholarly journals Temperature dependence of dynamic elastic moduli of wrought aluminum alloys

1972 ◽  
Vol 22 (12) ◽  
pp. 710-715 ◽  
Author(s):  
Hiroshi NEWKO ◽  
Shigeo ZAIMA ◽  
Yoitiro TAKEUTI ◽  
Kazuo TAMARU
Keyword(s):  
Aluminum Alloys ◽  
Temperature Dependence ◽  
Elastic Moduli ◽  
Dynamic Elastic Moduli ◽  
Wrought Aluminum Alloys ◽  
Wrought Aluminum

Studies the Properties of Polyaspartic Polyurea Coated Concrete under Coaction of Salt Fog and Freeze-Thaw

2012 ◽  
Vol 455-456 ◽  
pp. 781-785
Author(s):  
Ping Lu ◽  
Xin Mao Li ◽  
Xue Qiang Ma ◽  
Wei Bo Huang
Keyword(s):  
Elastic Modulus ◽  
Frost Resistance ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw ◽  
Decrease Rate ◽  
Thaw Cycle ◽  
Freeze Thaw Cycle ◽  
Salt Fog

. This paper mainly studied the properties of PAE polyurea coated concrete under coactions of salt fog and freeze-thaw. After exposed salt fog conditions for 200d, T3, B2, F2 and TM four coated concrete relative dynamic elastic modulus have small changes, but different coated concrete variation amplitude is different. T3 coated concrete after 100 times of freeze-thaw cycle the relative dynamic elastic modulus began to drop, 200 times freeze-thaw cycle ends, relative dynamic elastic modulus variation is the largest, decrease rate is 95%, TM concrete during 200 times freeze-thaw cycle, relative dynamic elastic modulus almost no change, B2 concrete and F2 concrete the extent of change between coating T3 and TM. After 300 times the freeze-thaw cycle coated concrete didn't appear freeze-thaw damage phenomenon. Four kinds of coating concrete relative dynamic elastic modulus variation by large to small order: T3 coated concrete > B2 coated concrete >F2 coated concrete > TM coated concrete, concrete with the same 200d rule. Frost resistance order, by contrast, TM coated concrete > B2 coated concrete > F2 coated concrete > T3 coated concrete.

scholarly journals The Effects of Creep on Elastic Modulus Measurement Using Nanoindentation

2000 ◽  
Vol 649 ◽  
Author(s):  
G. Feng ◽  
A.H.W. Ngan
Keyword(s):  
Elastic Modulus ◽  
Elastic Deformation ◽  
Elastic Moduli ◽  
Holding Time ◽  
Time Dependent ◽  
Nanoindentation Test ◽  
Modification Method ◽  
Unloading Rate ◽  
Modulus Measurement

ABSTRACTDuring the unloading segment of nanoindentation, time dependent displacement (TDD) accompanies elastic deformation. Consequently the modulus calculated by the Oliver-Pharr scheme can be overestimated. In this paper we present evidences for the influence of the measured modulus by TDD. A modification method is also presented to correct for the effects of TDD by extrapolating the TDD law in the holding process to the beginning of the unloading process. Using this method, the appropriate holding time and unloading rate can be estimated for nanoindentation test to minimise the effects of TDD. The elastic moduli of three materials computed by the modification method are compared with the results without considering the TDD effects.

Static and dynamic elastic moduli of rock in a complex axisymmetric stressed state

1984 ◽  
Vol 20 (5) ◽  
pp. 343-350 ◽  
Author(s):  
A. N. Stavrogin ◽  
G. G. Zaretskii-Feoktistov ◽  
G. N. Tanov
Keyword(s):  
Stressed State ◽  
Elastic Moduli ◽  
Dynamic Elastic Moduli

scholarly journals Use of Silica Fume and GGBS to Improve Frost Resistance of ECC with High-Volume Fly Ash

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Yushi Liu ◽  
Xiaoming Zhou ◽  
Chengbo Lv ◽  
Yingzi Yang ◽  
Tianan Liu
Keyword(s):  
Elastic Modulus ◽  
Sodium Chloride ◽  
Mass Loss ◽  
Frost Resistance ◽  
Chloride Solution ◽  
Sodium Chloride Solution ◽  
Tap Water ◽  
High Volume ◽  
Dynamic Elastic Modulus ◽  
Freeze Thaw

Fly ash (FA) has been an important ingredient for engineered cementitious composite (ECC) with excellent tensile strain capacity and multiple cracking. Unfortunately, the frost resistance of ECC with high-volume FA has always been a problem. This paper discusses the influence of silica fume (SF) and ground-granulated blast-furnace slag (GGBS) on the frost resistance of ECC with high volume of FA. Four ECC mixtures, ECC (50% FA), ECC (70% FA), ECC (30% FA + 40% SL), and ECC (65% FA + 5% SF), are evaluated by freezing-thawing cycles up to 200 cycles in tap water and sodium chloride solution. The result shows the relative dynamic elastic modulus and mass loss of ECC in sodium chloride solution by freeze-thaw cycles are larger than those in tap water by freeze-thaw cycles. Moreover, the relative dynamic elastic modulus and mass loss of ECC by freeze-thaw cycles increase with FA content increasing. However, the ECC (30% FA + 40% SL) shows a lower relative dynamic elastic modulus and mass loss, but its deflection upon four-point bending test is relatively smaller before and after freeze-thaw cycles. By contrast, the ECC (65% FA + 5% SF) exhibits a significant deflection increase with higher first cracking load, and the toughness increases sharply after freeze-thaw cycles, meaning ECC has good toughness property.

scholarly journals Study on the Mechanical Properties of Chlorine Saline Soil under the Interaction of Multiple Factors

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Anhua Xu ◽  
Pengcheng Wang ◽  
Jianhong Fang
Keyword(s):  
Elastic Modulus ◽  
Moisture Content ◽  
Mechanical Characteristics ◽  
External Environment ◽  
Confining Pressure ◽  
Dynamic Elastic Modulus ◽  
Dynamic Strain ◽  
Saline Soils ◽  
Loading Frequency ◽  
Failure Strength

The distribution of chlorine saline soils is extensive in Haixi region of Qinghai Province in Northwest China. Its natural and geographical conditions are unique, and the external environment varies greatly. To study the effects of variable external environment on the mechanical characteristics of chlorine saline soils, a number of unconsolidated undrained (UU) dynamic triaxial tests under different confining pressure, moisture content, and loading frequency were carried out. The dynamic stress–dynamic strain, failure strength, dynamic elastic modulus, and parameter of shear strength were analyzed. The triaxial test results demonstrated that the stress–strain curves of the soil were strain-hardening. The failure strength and dynamic elastic modulus increased with the increasing of confining pressure; the law with moisture content and loading frequency were inconsistent. The dynamic cohesion and dynamic friction angle increased with the increasing of loading frequency, but decreased with the increasing of moisture content. Besides, the significance analysis theory was used to analyze the effect degree of different factors. It found that the effects of confining pressure, loading frequency, and the interaction between confining pressure and frequency on mechanical characteristics were significant, but the moisture content had less effect.

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