Influence of base-rock characteristics on ground response

1971 ◽  
Vol 61 (5) ◽  
pp. 1213-1231
Author(s):  
John Lysmer ◽  
H. Bolton Seed ◽  
Per B. Schnabel
Keyword(s):  
Ground Response ◽  
Response Characteristics ◽  
Soil Deposits ◽  
Different Types ◽  
Analytical Procedures ◽  
Typical Soil ◽  
Base Rock

abstract The response characteristics of nine typical soil deposits over different types of base rock are studied in order to evaluate the influence of the base-rock characteristics on the surface accelerations. The study shows that the spectra for the surface accelerations are virtually independent of the properties of the base rock provided the latter is homogeneous. However, layering of the base rock may influence the surface acceleration spectra to an appreciable extent and certain types of analytical procedures may give grossly erroneous results for such cases.

Response characteristics of electromagnetic seismographs and their dependence on the instrumental constants

1949 ◽  
Vol 39 (3) ◽  
pp. 205-218
Author(s):  
S. K. Chakrabarty
Keyword(s):  
General Solution ◽  
Equation Of Motion ◽  
Harmonic Motion ◽  
Response Characteristics ◽  
Local Earthquakes ◽  
Simple Harmonic Motion ◽  
The Earth ◽  
Electromagnetic Seismograph ◽  
Different Types ◽  
Proper Values

Summary The equation of motion of the seismometer and the galvanometer in an electromagnetic seismograph has been derived in the most general form taking into consideration all the forces acting on the system except that produced by hysteresis. A general solution has been derived assuming that the earth or the seismometer frame is subjected to a sustained simple harmonic motion, and expressions for both the transient and the steady term in the solution have been given. The results for the particular case when the seismograph satisfies the Galitzin conditions can easily be deduced from the results given in the present paper. The results can now be used to study the response characteristics of all electromagnetic seismographs, whether they satisfy the Galitzin conditions or not, and will thus give an accurate theoretical picture of the response also of seismographs used for the study of “local earthquakes” and “microseisms” which do not in general obey the Galitzin conditions. The results obtained can also be used to get analytically the response of the seismographs for different types of earth motion from the very beginning, and not only after the transient term has disappeared. The theory of the response to simple tests used to determine the dynamic magnification of any seismograph and also to determine and check regularly the instrumental constants of the seismographs has been worked out. The results obtained can also be used for ascertaining the proper values of the instrumental constants suitable for the various purposes for which the seismographs are to be used.

Seismic ground-response studies in Olympia, Washington, and vicinity

1990 ◽  
Vol 80 (5) ◽  
pp. 1057-1078
Author(s):  
K. W. King ◽  
A. C. Tarr ◽  
D. L. Carver ◽  
R. A. Williams ◽  
D. M. Worley
Keyword(s):  
Seismic Waves ◽  
Hard Rock ◽  
Puget Sound ◽  
Open Pit ◽  
Site Conditions ◽  
Ground Response ◽  
Response Characteristics ◽  
Seismic Ground Response ◽  
Geological Units ◽  
The City

Abstract Relative seismic ground-response characteristics in the cities of Olympia, Lacey, and Tumwater, Washington, were determined from analysis of instrumentally recorded ground motion induced by blasts at an open-pit coal mine near Centralia, Washington. A ground-response function (GRF), defined as the ratio of Fourier spectral amplitudes at an alluvium site to spectral amplitudes on hard rock, is a measure of amplification of seismic waves by localized site conditions. GRF values in three frequency bands (0.5 to 1.0 Hz, 1.0 to 2.0 Hz, and 2.0 to 4.0 Hz) were compared with observed Modified Mercalli (MM) intensities from the 29 April 1965, Puget Sound earthquake and with mapped surficial geologic units. Typically, the GRF values relate well with the surficial geological units. In addition, MM intensities within the V to VII range appear to be directly related to the frequencies within the 0.5 to 4.0 Hz bandwidth such that MM V intensity sites had a lower GRF value in the 2.0 to 4.0 Hz bandwidth as compared to the 0.5 to 2.0 Hz bandwidth, and the MM VII intensity sites had higher GRF values in the 2.0 to 4.0 Hz bandwidth as compared to the 0.5 to 2.0 Hz bandwidth. The set of GRF values determined for the city of Olympia and its vicinity should be useful in formulating a theoretical relative ground-response model for the southern Puget Sound area.

ENGINEERING CHARACTERISTICS AND EARTHQUAKE RESPONSE ANALYSIS OF GROUND

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Haruyuki Yamamoto ◽  
Munkhunur Togtokhbuyan
Keyword(s):  
Shear Modulus ◽  
Ground Surface ◽  
Response Analysis ◽  
Soil Profiles ◽  
Lumped Mass ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Natural Period ◽  
Soil Deposits ◽  
Computational Procedures

One-dimensional layered soil lumped mass ground response analysis was conducted for the representative site in Ulaanbaatar, Mongolia. The surficial geology of the site is predominantly composed of the gravely and sandy soil typical of this region in the central part of Ulaanbaatar. The natural period of soil profiles needs to be investigated under several circumstances. For example, these parameters-based study has indicated that damage due to earthquakes occurs when the natural periods, T1 and T2, of the ground are closer to that of a superstructure. Various computational procedures or methods have been proposed for this kind of the ground response analysis. In this paper, the numerical analysis method such as the lumped mass method within eigenvalue analysis is used to determine the natural periods of the ground. The ground surface, soil deposits, and bedrock are assumed to be horizontal. The soil deposits are subjected to shear deformation such as shear modulus, G, on the other hand, excitation of vibration could be a shear modulus on each layer. As well as to determine an engineering bedrock depth in the site, the methodology that is utilized in this paper is focused on the use of the correlation between SPT-N value and soil elastic Young's modulus, E, in the soil profiles, and used over 100 boreholes data with SPT-N values in the vicinity of Ulaanbaatar.

Investigation on the Effect of Asymmetric Vane Spacing on the Reduction of Rotor Blade Vibration

2014 ◽  
Author(s):  
Yonghong Niu ◽  
Anping Hou ◽  
Mingming Zhang ◽  
Tianrui Sun ◽  
Rui Wang ◽  
...  
Keyword(s):  
Stress Amplitude ◽  
Vibration Reduction ◽  
Forced Response ◽  
Aerodynamic Load ◽  
Transient Method ◽  
Blade Vibration ◽  
Response Characteristics ◽  
Different Types ◽  
Vibration Stress ◽  
Reduction Effect

A transient method to analyze blade forced response under stator-rotor wake influence is proposed in dealing with asymmetric aerodynamic load. The vibration response of the blades is calculated in the fluid-structure coupled manner for the asymmetric vane spacing. Four different types of modification are adopted in the investigation. The reduction effect on the vibration stress due to the asymmetric vane spacing is examined by comparing the response characteristics of frequency and amplitude. Though the asymmetric vane spacing does not much affect the performance of the turbine, the results show that the proper asymmetric vane spacing can decrease the levels of the excitation force at specific frequencies to control the downstream blade forced response. The stress amplitude at the vane passing frequency is decreased by 51% in the most desirable modification in the study. After investigating the vibration characteristics of the blades under the wake excitation from upstream, the mechanism of the vibration reduction due to the asymmetric vane spacing is analyzed.

Pore pressure response analysis for earthquakes

1985 ◽  
Vol 22 (4) ◽  
pp. 466-476 ◽  
Author(s):  
Ashok K. Chugh ◽  
J. Lawrence Von Thun
Keyword(s):  
Pore Pressure ◽  
Effective Stress ◽  
Computer Programs ◽  
Pressure Response ◽  
Response Analysis ◽  
Earthquake Loading ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Soil Deposits ◽  
Pore Pressure Response

Modifications and extensions made to the computer programs APOLLO and GADFLEA for studying the generation and dissipation of pore water pressure in soil deposits under earthquake loading are presented. The revised versions of these computer programs permit a fuller use of the analytically estimated site-specific earthquake response of soil deposits. These changes do not, however, alter the basic formulation of the problem and the solution strategies implemented in the computer programs APOLLO and GADFLEA. It is argued that the dynamic pore pressure response results obtained through these programs when used iteratively with the total stress ground response analysis should yield results close to the true effective stress ground response analysis for earthquake loading. Key words: pore pressure, earthquakes, soil dynamics, analysis, effective stress, computer programs, liquefaction.

scholarly journals Interior of saxicolous lichens on different types of rocks as a habitat for microfungal communities in Upper Galilee, Israel

2019 ◽  
Vol 54 (1) ◽  
Author(s):  
Isabella Grishkan ◽  
Marina Temina
Keyword(s):  
Growth Form ◽  
Fungal Species ◽  
Lichen Species ◽  
Fungal Communities ◽  
Nutrient Sources ◽  
Long Period ◽  
Different Types ◽  
Endolichenic Fungi ◽  
Fungal Assemblages ◽  
Typical Soil

We examined the diversity and composition of fungi from the interior of saxicolous (rock inhabiting) lichens covering basaltic and chalk rocks at the Alma–Har-Ben-Zimra area of Upper Galilee, Israel. We also compared the composition of lichen-associated and soil microfungal communities inhabiting the two contrasting soil types in the area to trace possible sources of formation of endolichenic fungal assemblages. In the course of the study, 39 fungal species were isolated from the interior of 13 lichen species. Species richness of the endolichenic fungal communities was associated, to some extent, with the growth form of lichens, being higher in those lichens with thick, warted, and wrinkled thalli. Species composition of the communities was characterized by the dominance of melanin-containing microfungi with large, multicellular, and thick-walled spores that significantly increased in abundance in the summer. Dominant species were also known as endophytes and phylloplane-inhabiting fungi; at the same time, typical soil-borne species were extremely rare components of the isolated endolichenic communities. Some endolichenic melanized microfungi were comprised by coprophilous species prevailing in some lichen thalli; this observation was probably due to a long period of use of the studied area for cattle grazing. Protective morphological features are important for fungi inhabiting the interior of lichen thalli characterized by limited nutrient sources, low-water availability, and restricted aeration. In addition, endolichenic fungi should resist the activity of various extracellular secondary metabolites produced by their host lichen species.

scholarly journals Reliability on ProSHAKE 2.0 in the Assessment of One Dimensional Ground Response Analysis through Verification Example

2019 ◽  
Vol 8 (4S2) ◽  
pp. 56-59
Keyword(s):  
Maximum Amplitude ◽  
Response Spectra ◽  
Response Analysis ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Peak Displacement ◽  
Earthquake Motion ◽  
Soil Deposits ◽  
Time Histories ◽  
Frequency Domain Approach

It is understood from the recent destructive earthquakes, topography, nature of the bedrock and geometry of the soil deposits are the prime factors that made modifications to the underlying earthquake motion. The influence of such confined soil states on the strong earthquake motion plays a significant task in accessing the uniqueness of ground action. In this paper, the response of the soil layers to the earthquake action of the bedrock directly under it is determined. The analysis is done through frequency domain approach. Pro-shake software 2.0 is used to arrive the reliability of the ground response study. A wide variety of output parameters such as time histories of acceleration, velocity, displacement, shear stress, shear strain, response spectra and maximum amplitude of various parameters with depth are plotted and the other scalar parameters such as peak acceleration, peak velocity, peak displacement, RMS acceleration, arias intensity, predominant period and bracketed duration was computed.

scholarly journals Numerical Simulation of Dynamic Response Characteristics of Cutting Coal and Rock by a Roller Coal Cutter

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Kesong Fan ◽  
Yutong Feng ◽  
Ruoyang Kong ◽  
Hua Wei ◽  
Wenlong Jiao ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Experiments ◽  
Simulation Software ◽  
Dynamic Responses ◽  
Average Speed ◽  
Response Characteristics ◽  
Whole Process ◽  
Different Types ◽  
Finite Element Numerical Simulation ◽  
Dynamic Response Characteristics

Currently, the identification technology of rock-coal medium is not reliable and practical, so we cannot judge the cutting state of coal-winning machine in real time. Different dynamic responses over different medium types of rock-coal can indirectly reflect the physical and mechanical parameters of rock-coal. In this study, we establish the 3-D numerical model of cutting the rock and coal by the finite element numerical simulation software in which we obtain the whole process of numerical simulation of the roller cutting coal, mudstone, and sandstone, where different dynamic responses counterpart different types of rock and coal by means of numerical experiments. The results show that when the drum keeps the average speed of cutting coal and medium forward, the instantaneous speed which is close to the average speed will have a small jump. The average speed and the torque in the cutting process can be considered as good indices to evaluate the rock and coal types. The torque from high to low is as follows: sandstone, mudstone, and coal. The average speed from high to low is as follows: coal, mudstone, and sandstone. If the portion of rock is more, the torque is higher and the average speed is lower during cutting the roof foot. This research is helpful for identifying rock-coal medium types by using related instrument to record the dynamic responses of rock-coal medium types.

scholarly journals The Impact of Using Different Types of Soft Soils Treated by Stone Columns on Creep Behavior

2022 ◽  
Vol 961 (1) ◽  
pp. 012052
Author(s):  
Sura Tawfeeq Al-Auqbi ◽  
Nahla M. Salim ◽  
Mahmood R. Mahmood
Keyword(s):  
Soft Soil ◽  
Horizontal Displacement ◽  
Cohesive Soil ◽  
Stone Columns ◽  
Stone Column ◽  
Geometric Conditions ◽  
Improvement Factor ◽  
Soil Deposits ◽  
Different Types ◽  
The Impact

Abstract The stone column technique is an effective method to increase the strength of soft cohesive soil, which results in a reduction in foundation settlement and an increase in bearing capacity. The topic of restraining creep settlement through the use of stone columns techniques has gained increasing attention and consideration; because stone columns are widely used to treat soft soil deposits, caution should be applied in estimating creep settlement. We discovered a reversible relation between shear parameters and the creep settlement in floating stone columns; while, in case of end-bearing stone columns shows a direct positive relation between shear parameters and the creep settlement, and the creep settlement began at the primary settlement. The shear parameters affected the improvement factor (n) of creep settlement in both floating and end-bearing stone columns. The standard creep coefficient’s n values in floating and end-bearing conditions were more significant than the low creep coefficient’s n values in forwarded geometric conditions. The stress in both floating and end-bearing stone columns was increasing and uniformly distributed along the length of the floating stone column and in the case of end-bearing stone column was limited to the stiffness layer; the maximum vertical stress was in the central point of the embankment. The embankment’s maximum horizontal displacement occurred on the edge.

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