Browsing by Author "Huang, An-Bin"

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A Fiber Optic Sensored Triaxial Testing Device
(2011-03-01)
Lee, Jui-Ting
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Tien, Kai-Cheng
;
Ho, Yen Te
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Huang, An-Bin
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土木工程學系
The physical quantities involved in a triaxial testing device have mostly been monitored with electric sensors. These sensors are currently subject to short circuit when submerged under water and electromagnetic interference (EMI). Waterproofing and EMI noise filtration have often been a challenge to the triaxial test set-up. These drawbacks can be substantially minimized when using optic fiber sensors. The optic fiber Bragg grating (FBG) sensors have the additional advantage of being partially distributive where multiple sensors can share the same signal transmission line. Taking advantage of these unique capabilities, the authors explored the possibility of converting all pressure/force and linear displacement transducers in a triaxial testing device into FBG based sensors. A series of shearing tests on unsaturated and saturated soil specimens were carried out using the new FBG sensored triaxial testing device. In most cases, the measurement of physical quantities was paired with electric sensors so that the results can be compared. This paper describes the principles of the individual FBG sensor designs and demonstrates their applications in triaxial testing.
A mist pluviation method for reconstituting silty sand specimens
(2015-04-07)
Huang, An-Bin
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Chang, Wen-Jong
;
Hsu, Huai-Houh
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Huang, Yu-Jie
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土木工程學系
A mist pluviafion (MP) technique was proposed in an effort to develop a practical method for reconstituting silty sand specimens without inducing severe particle segregation. The mist pluviation method includes both air and water pluviation processes, with the addition of a mist zone that mixes soil particles with water droplets while falling through air. The soil and water mixtures have similar particle sizes, thus resulting in significantly reduced particle segregation. A thin water layer on top of the deposited soil mimics the water deposition process, and saturates the soil with little chance for particle segregation. The performance of the MP method was evaluated with regard to homogeneity, repeatability, undrained monotonic compression, and cyclic strength of triaxial specimens with various fines contents. Results have indicated that the MP method can be a promising technique to prepare reconstituted silty sand specimens. (C) 2015 Elsevier B.V. All rights reserved.
Characterization of reservoir sediment under water with differential pressure-sensored flat dilatometer and piezo-penetrometer
(2013-08-01)
Lee, Jui-Ting
;
Wang, Chien-Chih
;
Ho, Yen-Te
;
Huang, An-Bin
;
土木工程學系
The unusually strong typhoons and heavy rainfalls occurred recently in Taiwan have caused major landslides in many reservoir catch basins. The debris from these landslides eventually settled in the reservoir and turned into mud. From soil mechanics point of view, the mud immediately in front of the dam where the reservoir is usually the deepest is a very young, normally consolidated or under-consolidated fine-grained soil. The engineering properties of the reservoir mud are important parameters in the planning and design of schemes to remove the mud. Yet, our knowledge in this regard is very limited. For some of the major reservoirs in Taiwan, the mud is often under more than 40 m of water. How to conduct effective geotechnical site characterization under these circumstances is a challenge. The authors developed techniques to incorporate differential pressure measurements in flat dilatometer (Delta DMT) and piezo-penetrometer (Delta Pu) tests to facilitate in situ measurements under water in a reservoir. A series of field Delta DMT and Delta Pu tests along with representative soil sampling were conducted at Tsengwen Reservoir in southern Taiwan. The paper describes the techniques of Delta DMT and Delta Pu tests, interpretation of available test data to obtain the engineering properties of the reservoir mud, and discusses implications in the future site characterization of reservoir mud.
CORRELATING CYCLIC STRENGTH WITH FINES CONTENTS THROUGH STATE PARAMETERS
(2011-12-01)
Huang, An-Bin
;
Chuang, Sin-Yu
;
土木工程學系
;
Department of Civil Engineering
Attempts have been made in the past few decades to establish an equivalent void ratio indicative of the effective density state of sands that contain fines. The concept of an equivalent void ratio is most useful when the grain size distribution of the sand/silt mixture is similar to that of binary packing. Due to its grain characteristics and the wide range of compressibility when the fines content changes, correlating the cyclic strength to fines content via the equivalent void ratio for Mai Liao Sand (MLS) is not a straightforward procedure. Earlier studies have demonstrated the effectiveness of relating cyclic strength to state parameters for sands. Using a series of cyclic triaxial test results as a database, the authors demonstrated the effectiveness of relating cyclic strength to fines contents (f(e)) through a state parameter for MLS with an f(e) ranging from 0 to 30% that takes advantage of the equivalent void ratio. In addition to the density and stress states, the state parameter based correlations indirectly reflect the effects of soil grain characteristics. The drawback of requiring a separate critical state line when f, changes can be circumvented by using a unified critical state line based on the equivalent void ratio.
Development of a chirped/differential optical fiber Bragg grating pressure sensor
(2008-04-01)
Ho, Yen-Te
;
Huang, An-Bin
;
Lee, Jui-ting
;
土木工程學系
;
Department of Civil Engineering
With its unique capabilities, the optical fiber Bragg grating has been used as a key component in the development of many sensors. Incorporating the theory of thin plates, the authors have developed an FBG-based pressure sensor by strategically attaching FBGs on the surface of a thin circular plate. The flexural strain in the circular plate induced by pressure applied to the circular plate is sensed by either a single FBG placed radially crossing a neutral point, or two FBGs placed respectively in zones where the strains are of opposite signs. When one FBG is used (i.e., the chirped FBG design), the applied pressure relates to the change in the chirped bandwidth of the FBG reflected waveform. When two FBGs are used (i.e., the differential FBG design), the pressure experienced by the circular plate is correlated to the difference in central wavelength from the two FBGs. In either case the sensing mechanism is immune to temperature fluctuation. The same configuration can potentially be applied for other purposes such as a load cell or displacement transducer. This paper describes the design principles of the FBG pressure sensor and demonstrates its capabilities through laboratory calibrations over a wide range of temperatures.
Effects of seismic anisotropy and geological characteristics on the kinematics of the neighboring Jiufengershan and Hungtsaiping landslides during Chi-Chi earthquake
(2009-03-10)
Dong, Jia-Jyun
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Lee, Wang-Ru
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Lin, Ming-Lang
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Huang, An-Bin
;
Lee, Yen-Liang
The Chi-Chi earthquake (Mw=7.6) of September 21, 1999 triggered many landslides in central Taiwan. Two of these landslides, Hungtsaiping (HTP) and Jiufengershan (JFES) were situated as close as 2 km from each other but had significant differences in their kinematics. JFES landslide was a catastrophic rockslide-avalanche and the HTP landslide was relatively slow-moving. The authors conducted a study to explore the reasons for such differences. Factors such as the characteristics of strong ground motion, sliding direction of landslide, and friction angle of the sliding surface were considered in the study. An analysis of 12 strong-motion records collected in the study area showed that the distribution of horizontal pseudostatic coefficients, earthquake energy ratio and permanent sliding-block displacements (Newmark displacement) were anisotropic with their predominant direction mostly in the E/W-ESE/WNW trending. This direction is perpendicular to the axis of the main geological structures of the studied area. The computed Newmark displacement in the sliding direction of the JFES landslide is larger (44%) than that of the HTP landslide with sliding surface inclination of 21 degrees and friction angle of 28 degrees We can conclude that the seismic anisotropy and the corresponding sliding direction are important contributing factors to the kinematics of studied landslides. The back-calculated friction angle of the sliding surface that corresponds to a critical Newmark displacement for the JFES landslide is about 3.5 degrees higher than that of HTP landslide. The material (colluvium) on the sliding surface in HTP should be less velocity-dependent than that of the JFES landslide (rock) according to the back calculations. The importance of seismic anisotropy, sliding direction, and mechanical properties of sliding surface on the kinematics of deep-seated landslides is demonstrated. (c) 2007 Elsevier B.V. All rights reserved.
Fiber bragg grating sensored segmented deflectometer for ground displacement monitoring
(2007-03-29)
Huang, An-Bin
;
Ho, Yen-Te
The invention provides a monitoring device mainly for sensing ground displacement, including the fiber Bragg grating sensored deflectometer and the signal interrogator/computer system. The device uses a segmented design that consists of a flexible tube (referred to as the flexible segment) and two rigid segments and thus referred to as the FBG segmented deflectometer (FBG-SD). For field installation, multiple FBG-SD units are connected together to form a string as it is inserted into a grouted-in-place inclinometer casing. The distortion of the inclinometer casing induced by ground movement causes relative rotation of the inserted FBG-SD. All of the FBG-SD units are connected to an FBG interrogator/computer system situated on ground surface. The FBG signals are recorded and analyzed by the interrogator/computer system.
Fiber grating sensor
(2009-12-03)
Huang, An-Bin
;
Kao, Sheng-Chiang
A fiber grating sensor including an elastic circular plate and one or two FBG'ss attached to the bottom surface of the elastic circular plate. Two ends of the FBG are connected to an optic fiber for signal transmission. The fiber grating sensor readouts are independent of temperature variation. The fiber grating sensor mechanism according to the present invention may be applied in a variety of sensors such as gauge pressure transducer, differential pressure transducer, load cell and displacement transducer with a distributive design, and for various purposes.
FIELD EVALUATION OF THE CYCLIC STRENGTH VERSUS CONE TIP RESISTANCE CORRELATION IN SILTY SANDS
(2009-08-01)
Huang, An-Bin
;
Tai, Yuan-Yu
;
Lee, Wei F.
;
Huang, Yao-Tao
;
土木工程學系
The liquefaction potential assessment under the framework of simplified procedure that involves the use of cone penetration tests (CPT) typically relies on empirical correlations between the soil cyclic resistance ratio, CRR and cone tip resistance q(t). For sands that contain fines (particles passing #200 sieve), an adjustment based on fines content in the CRR-q(t) correlation is called for in currently available procedures. Earlier laboratory calibration tests in reconstituted silty sand specimens performed by the authors have indicated that partial drainage in CPT played an important role in the CRR-q(t) correlations. A series of laboratory tests on undisturbed samples and field piezocone penetration tests (CPTU) were carried out in an alluvial soil deposit at two test sites in Central and Southern Taiwan. The results indicated that unlike the uniformly mixed specimens reconstituted in laboratory, the tested natural alluvial silt/sand soils can be heterogeneous with closely spaced clean sand layers embedded in a matrix of silty material. This stratification can render the CPTU a drained test even at fines contents well in excess of 50%. The ignorance of free draining effects on CPTU due to stratification in alluvial soils may lead to overestimation of CRR. Because of these factors, calibration of the CRR-q(t) correlations by performing tests in local soil and field procedures to ascertain the drainage conditions in CPTU are important to the proper application of the CRR-q(t) correlations in the liquefaction potential assessment.
Geotechnical reconnaissance and liquefaction analyses of a liquefaction site with silty fine sand in Southern Taiwan
(2011-11-13)
Chang, Wen-Jong
;
Ni, Sheng-Huoo
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Huang, An-Bin
;
Huang, Yan-Hong
;
Yang, Yu-Zhang
Geotechnical reconnaissance of a recurrent liquefaction site at a Quaternary alluvial deposit in southern Taiwan was conducted to establish a comprehensive case history for liquefaction on silty fine sand with high fines content. The liquefaction occurred at a silty fine sand layer with D(50) = 0.09 mm and fines content greater than 35% and was triggered by a M(w) = 6.4 earthquake on March 4,2010, which induced maximum horizontal acceleration up to 0.189 g at the site. In situ subsurface characterizations, including standard penetration test, cone penetration test, and shear wave velocity measurement, were performed as well as cyclic simple shear tests on undisturbed specimens retrieved by a modified hydraulic piston sampler. Comparisons of cyclic resistance ratios (CRRs) indicate that CPT sounding with standard penetration rate could overestimate the resistance ratio and drainage conditions during penetration should be considered for high fines content soil in the liquefaction analysis. Additionally, variations of CRRs from different in situ tests indicate that correlations among in situ tests and CRR could be soil specific and precautions should be taken when using these curves on silty fine sands. (C) 2011 Elsevier B.V. All rights reserved.
Optic fiber bragg grating sensor
(2008-12-25)
Huang, An-Bin
;
Kao, Sheng-Chiang
The optic fiber Bragg grating (FBG) sensor comprises of an elastic circular diaphragm and one or two FBG attached to the bottom surface of the elastic circular diaphragm. Two ends of the FBG are connected to an optic fiber for signal transmission. The FBG sensor readouts are independent of temperature fluctuation. The FBG sensor mechanism according to the present invention may be applied for various purposes such as a gauge pressure transducer, differential pressure transducer, load cell and displacement transducer with distributive capabilities.
Physical simulation of aquifer compression due to groundwater fluctuation
(2017-12-14)
Chang, Wen-Jong
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Chou, Shih-Hsun
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Huang, An-Bin
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土木工程學系
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Department of Civil Engineering
To investigate the compression of granular aquifer induced by fluctuations of pore pressure, series of repeated pore pressure induced loading-unloading tests on specimens made of Ottawa sand mixed with mica were conducted in a K-o-triodal consolidation system. To simulate the stress paths in the field, the vertical displacements of soil specimens were monitored while maintaining a constant total vertical stress and applying sinusoidal fluctuations of pore pressure to specimens under K-o conditions. Shakedown theory is applied to interpret the testing data. The paper describes the laboratory setup, test procedure and findings from the test results. The results reveal that a shakedown behavior existed in saturated granular specimens and the accumulated permanent axial strains are 5 to 56 times of the values for conventional, monotonic loading. The finding evidently proves the significance of aquifer compression to ground subsidence due to repeated ground water fluctuations.
Simplified monitoring and warning system against rainfall-induced shallow slope failures
(2018-10-01)
Wang, Chien-Chih
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Chang, Wen-Jong
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Huang, An-Bin
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Chou, Shih-Hsun
;
Chien, Yu-Chun
A system that involves the use of a low-cost microelectromechanical system (MEMS)-based sensor stick and soil-water characteristic curve (SWCC) inferred from grain-size distribution was developed to assess the factor of safety against rainfall-induced shallow slope failure. The system allows water content at multiple depths to be monitored in the field. The corresponding suction and factor of safety against infinite slope failure are derived based on the estimated SWCC. The new system circumvents the use of tedious and often costly field as well as laboratory procedures while providing a quantitative slope stability assessment on a real-time basis. The paper introduces the background of the new development and describes the application of the sensor stick system in a field test.
Stability monitoring of rainfall-induced deep landslides through pore pressure profile measurements
(2012-08-01)
Huang, An-Bin
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Lee, Jui-Ting
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Ho, Yen-Te
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Chiu, Yun-Fang
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Cheng, Shyr-Yuan
It has long been recognized that field hydrological and geomechanical properties/conditions are the key elements controlling the stability of a slope under the influence of rainfall. Warning systems based on rainfall or ground displacement measurements are popular methods currently being used to minimize the hazards of landslides. When field hydrological monitoring is used, it usually involves a limited number of sensors for either positive or negative pore-water pressure measurements. The available numerical schemes that couple pore-water pressure with a geomechanical analysis are the most suitable for shallow slope failures. Due to the variable and transient nature of the hydrological conditions in earth slopes, field measurements that reflect the pore-water pressure profile on a realtime basis would be highly desirable. Thus, the authors have developed a piezometer system that is based on optical fiber Bragg grating (FBG) pressure sensors. With this system, an array of nine sensors was installed in a single, 60-m-deep borehole to monitor the pore-water pressure profile in a highway slope in Southern Taiwan. This paper describes the details of the FBG sensor array installation in the field and the data obtained throughout three typhoons from 2008 to 2010. The results demonstrate that the field readings can be readily incorporated into the existing mechanics-based analytical framework and can predict the potential of an upcoming slope failure. (C) 2012 The Japanese Geotechnical Society. Production and hosting by Elsevier B.V. All rights reserved.
紅菜坪地滑監測系統建立與變形機制研究(I)
(2005)
黃安斌
;
Huang, An-Bin
;
國立交通大學工學院防災工程研究中心
紅菜坪地滑範圍涵蓋數百公頃，其滑動機制複雜，無論從地表地形或地層移動來觀察此一地滑或從理論上來做力學行為分析都有其高度之挑戰性。台灣還有許多類似，具有滑動潛能之大型坡地。此類坡地如果發生滑動將造成重大人命財產之損失。如果能夠為此類坡地滑動建立一有效之監測與安全分析系統，將有助於國內地質災害之防制。本計畫將以紅菜坪地滑為對象，使用新近研發成功之光纖感應地層移動、水壓/水位監測與航測及其他影像技術分別從地層內部與地表來監測坡地的滑動。研究團隊同時也將在紅菜坪地區從事鑽探取樣以及針對取樣試體進行力學試驗，根據試驗結果配合地質背景以及過去受力之歷史以反算的方式來了解紅菜坪地滑發生之機制，從而建立台灣類似大型坡地監測、安全分析與災害防制之經驗，建立長期地滑之監測與研究示範區，並研提其他可能地滑災害地點持續研究建議。
道路邊坡高效能監測系統研發與崩塌預警基準制訂
(2003)
黃安斌
;
Huang, An-Bin
;
國立交通大學工學院防災工程研究中心
台灣多丘陵與山地，鐵公路系統大多位於山區。然而，台灣山區平均年降雨量高，每每大雨過後有很多路段都出現嚴重坍方或路基流失而造成阻斷，因此，山區道路邊坡的不穩定，直接影響道路使用者之安全。關於邊坡之整治，過去幾年之研究已提供許多重要之政策研擬參考方向，目前仍有許多重要之研究案正進行中或準備進行。然而，許多重要路段，或一再發生邊坡崩塌災害、或已有災害發生之潛能或徵兆、或因其重要性而有必要長期監控邊坡安全，均已設置或有必要設置邊坡安全監測系統，透過實測加以分析、研判並提供作為道路管理者之重要參考。本研究計畫第一年完成的工作項目包括：（1）文獻蒐集與整理；（2）傳統感測系統監測能量評估與彙整；（3）實驗室光纖監測與TDR監測技術與系統之研發與量測研究；（4）初步現地安裝與量測試驗研究；（5）崩塌預警基準制訂。第二年將延續第一年之研究成果，持續完成下列工作項目，包括：（1）監測技術之改善與研發；（2）監測技術評估；（3）現地監測與量測；（4）崩塌預警基準制訂範例；（5）先進科技於邊坡崩塌監測之推廣講習會。本計畫已研發成功光纖光柵彎曲變形監測管可以做地層移動監測之用，一系列使用TDR技術之監測系統包括地層錯動，水位監測，線性伸張以及雨量計等監測儀器也已研發完成，在未來將持續投入研究，以達研究計畫之目的。