Site-Dependent Building Response in Singapore to Long-Distance Sumatra Earthquakes

1997 ◽  
Vol 13 (3) ◽  
pp. 475-488 ◽  
Author(s):  
Tso-Chien Pan
Keyword(s):  
Tall Buildings ◽  
Long Distance ◽  
Quaternary Deposit ◽  
High Exposure ◽  
Highly Active ◽  
Geological Conditions ◽  
Measurement Results ◽  
Microtremor Measurement ◽  
City State ◽  
Sumatra Earthquakes

Singapore is a city state located in a low seismicity area with mild winds. The country is a classic example of low seismic hazard and high exposure scenario. It is about 400 km away from a highly active earthquake belt, the Sumatra subduction complex, where great earthquakes have occurred in the past. Twenty-seven earthquakes have been reportedly felt in Singapore since the British settlement in 1819. The frequency of these felt events seems to be rising with time as the country develops. The response of a building to long-distance earthquakes is dependent on the type of structural systems and the local geological conditions. Tall buildings founded on Quaternary deposit, i.e. the Kallang Formation, are particularly apt to respond to the long-distance Sumatra earthquakes. Microtremor measurement results correlate well with the geological conditions and give evidence to the phenomenon of site dependent building response in Singapore to the long-distance Sumatra earthquakes.

Theoretical investigation into the measurability of rail unevenness and corrugation using the dynamic response of axle box and bogie

2020 ◽  
pp. 095440972092321
Author(s):  
Yurong Wang
Keyword(s):  
Dynamic Response ◽  
Standing Waves ◽  
Vehicle Speed ◽  
Long Distance ◽  
Rail Corrugation ◽  
Track Maintenance ◽  
Track System ◽  
Measurement Results ◽  
Ballasted Track ◽  
Rail Irregularity

Monitoring track unevenness is important for noise and vibration control and track maintenance. Rail corrugation and shorter wavelength track unevenness can be measured using the corrugation analysis trolley, but it is not suitable for measurement over long distance. It is of great significance to study the dynamic behavior of the response of the axle box and bogie to the unevenness excitation for a better understanding of the measurement results. In this paper, the dynamic response of the axle box and bogie to the unevenness excitation is analyzed in the frequency domain by taking account of multiple wheel–rail interactions, which is the case in practice. The response of the axle box and bogie is found to be affected by the so-called P2 resonances at low and medium frequencies and the standing waves of rail vibration at higher frequencies due to the multiple wheel–rail interactions. Based on the analysis of the response of the axle box and bogie, the measurability of track unevenness is discussed. Results show that the measurement of rail unevenness using the axle box response is mainly limited by the P2 resonance. The frequency range of measurement for the ballasted track studied is estimated to be 1–35 Hz, corresponding to the measurable unevenness wavelength of 0.6–20 m (or longer) at a vehicle speed of 20 m/s. Above 200 Hz, the standing waves of rail vibration will cause serious uncertainty in the measurement of short wavelength rail irregularity using the axle box response for the resilient track. Short pitch rail corrugation, however, can be evaluated using the axle box response due to its strong correlation with certain modes of the wheel–track system.

scholarly journals The problem of credibility studies on deformations of engineering objects in the geologically unstable area of Szczecin

2018 ◽  
Vol 71 ◽  
pp. 00018
Author(s):  
Marek Zygmunt ◽  
Stefan Cacoń ◽  
Andrzej Piotrowski ◽  
Grzegorz Stępień
Keyword(s):  
Measurement System ◽  
Geological Structure ◽  
Reference Points ◽  
Test Method ◽  
Geological Conditions ◽  
Measurement Results ◽  
Basic Issue ◽  
Class 1 ◽  
Proper Diagnosis ◽  
Control And Measurement System

The location of reference points in deformation studies of engineering objects is often associated with low reliability of the obtained measurement results. This concerns the lack of proper diagnosis of the geological structure of the area. The reliability of deformation measurements is also low when we obtain data that only characterize the effects and not the cause-and-effects. The authors reviewed the influence of geological conditions on the formation of deformations of some engineering objects. The reference points were located in the immediate vicinity of the facilities, without taking into account the geological structure of the areas where the facilities were located. The proposed test method is based on a three-segment control and measurement system. An example of such considerations is the engineering facilities on the Grodzka and Ostrów Grabowski Island in the Szczecin area. The basic issue is to locate geologically stable areas in the vicinity of monitored engineering objects on the basis of geological substrate assessment and to analyse archival materials concerning periodical measurements of class 1 and 2 levelling lines in the Szczecin area. Reference points are located, which constitute the first segment of the control and measurement system. Subsequent segments of the system are organized with reference to the points of the first segment. This method provides reliable data on deformations of engineering objects.

scholarly journals Study on Borehole Arrangement Methods for Gas Extraction by Hydraulic Slotting in Long-Distance Through-Coal Seam Tunnel

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Cunfang Zhu ◽  
Shuang Cai
Keyword(s):  
Numerical Simulation ◽  
Coal Seam ◽  
Simulation Models ◽  
Gas Production ◽  
Gas Extraction ◽  
Long Distance ◽  
Pressure Relief ◽  
Coal Deposits ◽  
Geological Conditions ◽  
Rapid Pressure

How to quickly eliminate outburst in long-distance through-coal seam tunnels is one of the major challenges faced by the tunnel industry in mountainous areas. Compared with coal mine rock crosscut coal uncovering, the work surrounding the rock of through-coal seam tunnels has a high degree of breakage, large cross-section of coal uncovering, and tight time and space. In this paper, a method of networked slotting in long-distance through-coal seam tunnels for rapid pressure relief and outburst elimination is proposed. Based on this method, the corresponding mathematical governing equations and numerical simulation models have been established. The optimal borehole arrangement spacing and the slot arrangement spacing obtained by numerical optimization are 2.85 m and 3.1 m, respectively. Field gas production data of through-coal seam tunnels show that compared with the traditional dense-borehole gas extraction, the method of networked slotting in long-distance through-coal seam tunnels for rapid pressure relief and outburst elimination can shorten the extraction time by about 66%, the net quantity of peak extraction is increased by 3.55 times, and the total quantity of gas extraction when reaching the outburst prevention index is increased by 1.26 times, which verifies the feasibility of this method and the reliability of numerical simulation results. This study could be used as a valuable example for other coal deposits being mined under similar geological conditions.

scholarly journals Vulnerability Of The Garut District Region In Tarogong Kalam, Tarogong Kidul, Garut Kota, And Karang Pawitan Sub-District Based On Microtremor Measurement

2020 ◽  
Vol 11 (1) ◽  
pp. 11
Author(s):  
Rahmat Setyo Yuliatmoko
Keyword(s):  
Seismic Vulnerability ◽  
Vulnerability Index ◽  
Dominant Frequency ◽  
Mitigation Measures ◽  
Ratio Method ◽  
Tectonic Earthquake ◽  
Wave Amplification ◽  
Geological Conditions ◽  
Microtremor Measurement ◽  
The Impact

The Tasikmalaya M 7.3 earthquake on September 2, 2009 had an impact on Garut, damaged infrastructure and claimed many lives. From the search results there were five areas that were severely damaged by tectonic earthquake shocks, which included Pemeungpeuk, Cisompet, Cikelet, Peundeuy and Banjarwangi Subdistricts, so that earthquake mitigation measures were needed. One of the mitigations that can research how the impact is if the potential for earthquake disasters occur below the southern surface of Java. The final objective of this research is to map disaster-prone zones in Tarogong Kaler, Tarogong Kidul, Garut City, and Karang Pawitan, Garut Subdistrict, based on dominant frequency values, Vs30, seismic vulnerability indexes, and GSS (Ground Shear Strains) so that they can know the land movement that is. Retrieval of data in this study by measuring geophysicaly methods in the field. Processing data using HVSR (Horizontal to Vertical Spectra Ratio) method, then mapped with ArcGis to interpret the zoning of the study area. Based on the research, we known that the dominant frequency distribution value is between 1-5.2 Hz. The seismic vulnerability index values calculated the study area are between 3 – 45, GSS values in the study area between 3 ×10-4 - 42×10-4. By looking at the spatial distribution of the values of f0, Kg and GSS the areas of Karangmulya, Jatiasih, Sidanggalih and Godog villages are types of young volcanic sediments classified as soft soils that are easily to wave amplification and earthquake vibrations, so that they are easily damaged during large earthquakes. in this region qualify as earthquake resistant buildings to minimize damage and losses, while Sukabakti, Kersamenak, Sukajaya, and Mekargalih villages in the west with the geological conditions of the surrounding area which is hard land so that it will be safer when an earthquake occurs.

scholarly journals Evaluation of the Diethylene Glycol Regeneration rate in Gas Fields Based on Indirect Measurements

2021 ◽  
Vol 2096 (1) ◽  
pp. 012120
Author(s):  
A N Krasnov
Keyword(s):  
Diethylene Glycol ◽  
Treatment Plant ◽  
Treatment Efficiency ◽  
Long Distance ◽  
Indirect Measurements ◽  
Regeneration Rate ◽  
Gas Treatment ◽  
Measurement Results ◽  
Gas Fields

Abstract Gas dehydration in the field is a mandatory procedure before long-distance transportation. In Russia, gas is dried by absorption using diethylene glycol (DEG). Upon absorbing moisture from the raw gas, DEG is regenerated and recycled to dehydration, the quality of which largely depends on the regeneration rate. This indicator is not measured directly at the dehydration plant, and regeneration is controlled discretely based on the periodic laboratory analysis results. The paper describes a virtual analyzer determining the DEG concentration in a real-time mode based on the temperature and DEG consumption measurement results. The regression mathematical model underlying the virtual analyzer has been built based on experimental data obtained at the Yamburg gas condensate field. As part of the gas treatment plant APCS, a virtual analyzer improves the treatment efficiency and reduces the DEG consumption.

THE DEVELOPMENT OF MULTIPLE CHOICE ACHIEVEMENT TESTS FOR EVALUATION OF GEOGRAPHY LEARNING OUTCOMES STUDENTS OF SECOND GRADE AT SENIOR HIGH SCHOOL

2018 ◽  
Vol 2 (2) ◽  
pp. 118
Author(s):  
Ayu Rahma Nengsi
Keyword(s):  
Test Validity ◽  
Multiple Choice ◽  
Achievement Tests ◽  
Poor Quality ◽  
Achievement Test ◽  
Test Reliability ◽  
High Exposure ◽  
Measurement Results ◽  
Teachers And Students ◽  
Validity Tests

The ability of teachers who are still minimal in developing achievement tests with appropriate procedures results in tests that are of poor quality, ultimately impacting measurement results that are less reliable. This encourages researchers to develop achievement test instruments that are in accordance with the correct test development procedures. This study aims to develop a multiplechoice test that is valid and reliable, as well as practical to be used by evaluators as well as by evaluation target objects. The method used in this study is research and development methods, using the Instructional Development Institute model (IDI) with three stages of development namely 1) define, 2) develop and 3) evaluate. Product testing is limited to 38 students. The research data is obtained in quantitative form in the form of student responses to tests, expert validation and practical questionnaires by teachers and students. Data analysis techniques use classical theory, test validity tests, test reliability tests, and practical tests. The results of the study are in the form of products of multiple choice achievement test instruments. Based on the results of the tests, the test instruments that are developed had good grain quality with a moderate level of difficulty and high exposure power, the results of the measurements are valid and reliable or reliable and had a small standard error of measurement which is 2.82, which meant that the measurement results are accurate.

Heralded Entanglement Between Widely Separated Atoms

Science ◽  
2012 ◽  
Vol 337 (6090) ◽  
pp. 72-75 ◽  
Author(s):  
Julian Hofmann ◽  
Michael Krug ◽  
Norbert Ortegel ◽  
Lea Gérard ◽  
Markus Weber ◽  
...  
Keyword(s):  
Quantum Mechanics ◽  
Quantum Communication ◽  
Information Science ◽  
Essential Feature ◽  
Quantum Systems ◽  
Long Distance ◽  
Quantum Information Science ◽  
Classical Statistics ◽  
Measurement Results ◽  
Generation Of Entanglement

Entanglement is the essential feature of quantum mechanics. Notably, observers of two or more entangled particles will find correlations in their measurement results that cannot be explained by classical statistics. To make it a useful resource, particularly for scalable long-distance quantum communication, the heralded generation of entanglement between distant massive quantum systems is necessary. We report on the creation and analysis of heralded entanglement between spins of two single rubidium-87 atoms trapped independently 20 meters apart. Our results illustrate the viability of an integral resource for quantum information science, as well as for fundamental tests of quantum mechanics.

scholarly journals Method of improving large-scale measurement accuracy of laser tracker based on photogrammetry

2019 ◽  
Vol 52 (9-10) ◽  
pp. 1220-1227 ◽  
Author(s):  
Chengyang Zhang ◽  
Xishuang Jing ◽  
Siyu Chen ◽  
Xuanzhe Ling ◽  
Jiarong Zou ◽  
...  
Keyword(s):  
Large Scale ◽  
Measurement Accuracy ◽  
Measurement Data ◽  
Correction Method ◽  
Laser Tracker ◽  
Digital Measurement ◽  
Long Distance ◽  
Measurement Results ◽  
High Measurement ◽  
Coordinate Correction

Background: When performing the spatial large-scale measurements, the measurement accuracy of laser tracker would decreased with the increase of the measurement distances due to the refraction difference of most optical digital measurement devices. Therefore, this paper proposed a method based on photogrammetry system to improve the large-scale measurement accuracy of the laser tracker. Purpose: The purpose of this method is to improve the large-scale measurement accuracy of the laser tracker by considering the advantages of photogrammetry system such as high measurement accuracy and good portability. Methods: The measurement data from the photogrammetry system would be used as a reference to do correction on measurement results from laser tracker. The coordinate correction method based on Rodrigues’ rotation formula has been discussed. The measurement accuracy of the long-distance point of laser tracker can be significantly improved through the coordinate correction method. Conclusion: Based on the advantages of using photogrammetry system, the proposed method can achieve higher accuracy when measuring the common points at a closer distance than the laser tracker can do when measuring objects far away from instrument. The feasibility of the proposed method has been demonstrated by experiment.

Design of Long-Distance and High-Accuracy Rail Subgrade Deformation Monitoring System Based on Zigbee Wireless Network

2013 ◽  
Vol 303-306 ◽  
pp. 676-684 ◽  
Author(s):  
Chun Hui Gong ◽  
Guo Qiang Zeng ◽  
Liang Quan Ge ◽  
Cheng Jun Tan ◽  
Qun Luo ◽  
...  
Keyword(s):  
Wireless Network ◽  
Monitoring System ◽  
Satellite System ◽  
High Accuracy ◽  
Deformation Monitoring ◽  
Long Distance ◽  
Term Stability ◽  
Long Term Stability ◽  
Remote Server ◽  
Measurement Results

A design of long-distance and high-accuracy rail subgrade deformation monitoring system based on Zigbee wireless network is proposed according to the requirement of inclination measurement for the Qinghai-Tibet railway rail subgrade. This paper selects Atmega128 as the microprocessor of the system, and uses SCA103T as high accuracy inclination sensor. When the real time inclination data has been collected and analyzed, GPRS network and Beidou satellite system should send the data to remote server, which can exhibit the deformation of rail subgrade after processing and analyzing the data comprehensively. The measurement results show that the short-term stability reaches 0.01°, and long-term stability reaches 0.02°. The final application distance is nearly 378 kilometers.

Precise Study and Application of Long Distance Lead Forecast Technology in Tunnel

2012 ◽  
Vol 490-495 ◽  
pp. 417-422
Author(s):  
Wei Dong Pan ◽  
Yong Lei Luo ◽  
Ren Guo Gu ◽  
Zheng Bo Hu ◽  
Fan Cheng Mao
Keyword(s):  
Reliable Data ◽  
Surrounding Rock ◽  
Long Distance ◽  
Mountain Ridge ◽  
Tunnel Face ◽  
Geological Conditions ◽  
Precise Study

It is important to accurately previse the circumstances of the tunnel face in advance to realize a safe construction, because of the polytrope and indefinability to mountain ridge tunnel surrounding rock. However, it is also painful evaluating the detecting zone precisely because of the influence of complex geological conditions and uncertain interpreting outcome. With the study and application on long distance lead forecast in Sheng Ren Moutain tunnel of Mei Zhou-Da Pu highway using TSP48, this paper introduces the principle of parameters electing in data managing and detecting to achieve precisely explaining about the detecting zone. The interpretation is not only more close to practice, but also can provide a piece of reliable data to the construction, which can effectively promote the construction safe.

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