scholarly journals COMPARISON OF BEDROCK AND SURFACE TIME HISTORIES SUBJECTED TO SUBDUCTION EARTHQUAKES IN A SELECTED LOCATION OF YOGYAKARTA

2019 ◽  
Vol 17 (63) ◽  
Author(s):  
Mochamad Teguh
2015 ◽  
Vol 77 (11) ◽  
Author(s):  
B.M. Hutapea ◽  
M. Asrurifak ◽  
Hendriyawan Hendriyawan ◽  
Masyhur Irsyam

It is not the earthquake but the collapse of the building and infrastructure that will cause the damage and the loss of human lives. To mitigate these hazards, the building and infrastructure need to be designed such that will not collapse due to earthquake. This paper presents the procedure for generating time histories at ground surface for Jakarta area. Required data to generate these modified time histories were extracted from the Team for Revision of Seismic Hazard Maps of Indonesia 2010. The results are used as input motions in dynamic time history analysis for predicting earthquake design loads for infrastructures, such as bridges such that those structures can be designed to bear the impact of an earthquake and prevent collapse


1970 ◽  
Vol 1 (12) ◽  
pp. 26 ◽  
Author(s):  
E. Clark McNair ◽  
Robert M. Sorenson

A two-dimensional model submerged offshore bar was installed in a Texas A&M Hydrodynamics Laboratory wave tank Monochromatic waves with a range of heights and periods were generated at this bar for three different depths of water over the bar For each wave, water surface time-histories were measured at points before and after the bar and spectral analyses of these measurements were performed The analysis of each wave record yielded an equivalent wave height which is proportional to the square root of the wave energy per unit surface area The ratio of the reformed to incident equivalent wave height is shown to relate to the ratio of incident wave height to water depth over the bar The predominant periods of the reformed waves are found to be the same as for the incident waves but the presence of energy at higher frequencies is also observed The cause of these higher frequency waves is discussed.


2000 ◽  
Vol 1 (4) ◽  
pp. 2
Author(s):  
R. R. Putz

The establishment of quantitative relationships between recorded wave-system characteristics and other phenomena requires numerical description of the wave record. Current concepts applied to time histories of wave activity at a point are discussed. Characteristic statistical regularities found in wave measurements are described. Examples given show the application of statistical techniques' to the description of wave systems in terms of the distribution of spectral energy as well as the distributions of "individual" wave heights and periods. Results from the prediction, from one point to another, of surface time histories illustrate the application of approximate spectral information.


1976 ◽  
Vol 66 (3) ◽  
pp. 937-958
Author(s):  
William B. Joyner ◽  
Richard E. Warrick ◽  
Adolph A. Oliver

abstract A four-level downhole array of three-component instruments was established on the southwest shore of San Francisco Bay to monitor the effect of the sediments on low-amplitude seismic ground motion. The deepest instrument is at a depth of 186 m—2 m below the top of the Franciscan bedrock. Earthquake data from regional distances (29 km ≦ Δ ≦ 485 km) over a wide range of azimuths are compared with the predictions of a simple plane-layered model with material properties independently determined. Spectral ratios between the surface and bedrock, computed for the one horizontal component of motion that was analyzed, agree rather well with the model predictions; the model predicts the frequencies of the first three peaks within 10 per cent in most cases and the height of the peaks within 50 per cent in most cases. Surface time histories computed from the theoretical model predict the time variations of amplitude and frequency content reasonably well, but correlations of individual cycles cannot be made between observed and predicted traces.


2011 ◽  
Vol 250-253 ◽  
pp. 3822-3826 ◽  
Author(s):  
Xian Mai Chen ◽  
Xia Xin Tao ◽  
Gao Hang Cui ◽  
Fu Tong Wang

The general track spectrum of Chinese main railway lines (ChinaRLS) and the track spectrum of American railway lines (AmericaRLS) are compared in terms of character of frequency domain, statistical property of time domain samples and dynamic performance. That the wavelength range of the ChinaRLS, which is characterized by the three levels according to the class of railway line, is less than AmericaRLS at common wave band of 1~50m is calculated. Simultaneously, the mean square values of two kinds of track spectra are provided at the detrimental wave bands of 5~10m, 10~20m, and so on. The time-histories of ChinaRLS and AmericaRLS are simulated according to the trigonometric method, and the digital statistical nature of simulated time samples is analyzed. With inputting the two kinds of time-histories into the vehicle-railway system, the comparative analysis of the two kinds of dynamic performances for ChinaRLS and AmericaRLS is done in terms of car body acceleration, rate of wheel load reduction, wheel/rail force, and the dynamic responses of track structure. The result shows that ChinaRLS can characterize the feature of the Chinese track irregularity better than AmericaRLS, the track irregularity with the ChinaRLS of 200km/h is superior to the AmericaRLS, and the track irregularity with the ChinaRLS of 160km/h corresponds to with the sixth of AmericaRLS.


2021 ◽  
pp. 875529302110279
Author(s):  
Sanaz Rezaeian ◽  
Linda Al Atik ◽  
Nicolas M Kuehn ◽  
Norman Abrahamson ◽  
Yousef Bozorgnia ◽  
...  

This article develops global models of damping scaling factors (DSFs) for subduction zone earthquakes that are functions of the damping ratio, spectral period, earthquake magnitude, and distance. The Next Generation Attenuation for subduction earthquakes (NGA-Sub) project has developed the largest uniformly processed database of recorded ground motions to date from seven subduction regions: Alaska, Cascadia, Central America and Mexico, South America, Japan, Taiwan, and New Zealand. NGA-Sub used this database to develop new ground motion models (GMMs) at a reference 5% damping ratio. We worked with the NGA-Sub project team to develop an extended database that includes pseudo-spectral accelerations (PSA) for 11 damping ratios between 0.5% and 30%. We use this database to develop parametric models of DSF for both interface and intraslab subduction earthquakes that can be used to adjust any subduction GMM from a reference 5% damping ratio to other damping ratios. The DSF is strongly influenced by the response spectral shape and the duration of motion; therefore, in addition to the damping ratio, the median DSF model uses spectral period, magnitude, and distance as surrogate predictor variables to capture the effects of the spectral shape and the duration of motion. We also develop parametric models for the standard deviation of DSF. The models presented in this article are for the RotD50 horizontal component of PSA and are compared with the models for shallow crustal earthquakes in active tectonic regions. Some noticeable differences arise from the considerably longer duration of interface records for very large magnitude events and the enriched high-frequency content of intraslab records, compared with shallow crustal earthquakes. Regional differences are discussed by comparing the proposed global models with the data from each subduction region along with recommendations on the applicability of the models.


2021 ◽  
Vol 156 ◽  
pp. 107660
Author(s):  
James C. Peyton Jones ◽  
Saeed Shayestehmanesh

Author(s):  
Christian Raab ◽  
Kai Rohde-Brandenburger

AbstractThe determination of structural loads plays an important role in the certification process of new aircraft. Strain gauges are usually used to measure and monitor the structural loads encountered during the flight test program. However, a time-consuming wiring and calibration process is required to determine the forces and moments from the measured strains. Sensors based on MEMS provide an alternative way to determine loads from the measured aerodynamic pressure distribution around the structural component. Flight tests were performed with a research glider aircraft to investigate the flight loads determined with the strain based and the pressure based measurement technology. A wing glove equipped with 64 MEMS pressure sensors was developed for measuring the pressure distribution around a selected wing section. The wing shear force determined with both load determination methods were compared to each other. Several flight maneuvers with varying loads were performed during the flight test program. This paper concentrates on the evaluation of dynamic flight maneuvers including Stalls and Pull-Up Push-Over maneuvers. The effects of changes in the aerodynamic flow characteristics during the maneuver could be detected directly with the pressure sensors based on MEMS. Time histories of the measured pressure distributions and the wing shear forces are presented and discussed.


Author(s):  
Daniele Dessi ◽  
Sara Siniscalchi Minna

A combined numerical/theoretical investigation of a moored floating structure response to incoming waves is presented. The floating structure consists of three bodies, equipped with fenders, joined by elastic cables. The system is also moored to the seabed with eight mooring lines. This corresponds to an actual configuration of a floating structure used as a multipurpose platform for hosting wind-turbines, aquaculture farms or wave-energy converters. The dynamic wave response is investigated with numerical simulations in regular and irregular waves, showing a good agreement with experiments in terms of time histories of pitch, heave and surge motions as well as of the mooring line forces. To highlight the dynamical behavior of this complex configuration, the proper orthogonal decomposition is used for extracting the principal modes by which the moored structure oscillates in waves giving further insights about the way waves excites the structure.


Sign in / Sign up

Export Citation Format

Share Document