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Monitoring and Warning of Landslides and Debris Flows Using an Optical Fiber Sensor Technology

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Journal of Mountain Science 2011年第5期8卷 728-738页

作者： PEI Huafu CUI Peng YIN Jianhua ZHU honghu CHEN Xiaoqing PEI Laizheng department of civil and {2. engineering the Hong Kong Polytechnic University Hong Kong China Institute of Mountain Hazards and Environment CAS Chengdu 610041 China School of Earth Sciences and engineering Nanjing University Nanjing 210093 China

Landslides and debris flows are typical geo-hazards which occur in hilly or mountainous regions. Debris flows may result from landslides. Geotechnical instrumentation plays an important role in monitoring and warning of landslides and resulted debris flows. Traditional technologies for monitoring landslides and debris flows have certain limitations. The new optical fiber sensors presented in this paper can overcome those limitations. This paper presents two new optical fiber sensor systems: one is the Fiber Bragg Grating (FBG)-based in-place inclinometer for monitoring landslides and the other is the FBG-based column-net system for monitoring debris flows. This paper presents the calibration results of FBG-based in-place inclinometers in laboratory. It is found that the calibration results are in good agreement with theoretical results. Both the FBG-based in-place inclinometers and the FBG-based column-net system have been installed at a site in Weijiagou valley, Beichuan County, Sichuan Province of china. Some preliminary results have been obtained and reported in the paper. The advantages of the FBG monitoring systems and their potential applications are also presented.

关键词： Landslide Debris flow Fiber Bragg Grating In-place inclinometer Column-net system

维普期刊数据库

FRP Composites for Retrofit and Construction of Structures:Recent Research at The hong kong polytechnic university

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FRP Composites for Retrofit and Construction of Structures:R...

第三届全国FRP学术交流会议

作者： J.G Teng department of civil and {2. engineering The hong kong polytechnic university hong kong, china

＜正＞ At The hong kong polytechnic university, on-going research addresses many aspects of the theory of FRP-strengthened structures and the innovative use of FRP composites in new construction. A very brief summary of some of the recent research progresses made at The hong kong polytechnic university （PolyU） is given here. Further details of these recent developments can be found in the references listed at the end. Some of the research summarized here has been carried out in collaboration with researchers at other institutions, including the {2. of Edinburgh, Tsinghua {2., Zhejiang {2., the {2. of Adelaide, Fuzhou {2., Jinan {2. and the National engineering Research Centre for Diagnosis and Rehabilitation of Industrial Buildings.

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ANALYSIS OF BIFURCATION BUCKLING IN SHELLS OF REVOLUTION AFTER AXISYMMETRIC SNAP-THROUGH

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ANALYSIS OF BIFURCATION BUCKLING IN SHELLS OF REVOLUTION AFT...

Asia-Pacific Conference on Shell and Spatial Structures

作者： J.G.TENG Y.F.LOU department of civil and {2. engineering The hong kong polytechnic university hung hom Kowloon hong kong

＜正＞Shells of revolution subject to axisymmetric loads often fail by non-symmetric bifurcation buckling after nonlinear axisymmetric deformations.A number of computer programmes have been developed in the past decades for these problems,but none of them is capable of bifurcation analysis on the descending branch of the primary load- deflection path following axisymmetric collapse/*** paper presents the first finite element formulation of post-collapse bifurcation analysis of axisymmetric shells in which a modified arc-length method is developed to effect a new automatic bifurcation solution *** examples are presented to demonstrate the capability of the formulation and the practical importance of post-collapse bifurcation analysis.

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Test on Sensor Effect of Cement Matrix Piezoelectric Composite

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Transactions of Tianjin university 2005年第2期11卷 133-136页

作者：杨晓明李忠献丁阳李宗津 School of civil engineering Tianjin university Tianjin 300072 china department of civil and Environmental {2. hong kong {2. of Science and Technology hong kong

A novel cement matrix smart piezoelectric composite and its application as sensing element are presented.A cement matrix smart piezoelectric composite piece encapsulated in a cement mortar formed a practical sensor, and it was tested on material test system with cyclic *** to the theoretical analysis, the function of the cement matrix piezoelectric sensor output voltage was expressed in terms of the magnitude of the input cyclic loading amplitude and *** curve fitting of gain function that is defined as sensor′s gain factor under different frequencies of input loading was carried out. From the results of curve fitting, it is found that the cement matrix smart piezoelectric composite has a simple relationship between input loading and output *** the cement matrix piezoelectric composite sensor is suitable to be applied in structural health monitoring.

关键词： piezoelectric composite cement matrix sensor structural health monitoring

Compressive Strength Development and Microstructure of Cement-asphalt Mortar

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Journal of Wuhan university of Technology(Materials Science) 2011年第5期26卷 998-1003页

作者：王强阎培渝 department of civil {2. Tsinghua University

The compressive strength developing process and the microstructure of cement-asphalt mortar （CA mortar） were *** fluidity of CA mortar has a great influence on its *** optimum value of spread diameter of slump flow test is in the range of 300 to 400 *** compressive strength of CA mortar keeps a relatively high growth rate in 56 days and grows slowly *** residual water of hydration in CA mortar freezes under minus environmental temperature which can lead to a significant reduction of the strength of CA *** A/C retards asphalt emulsion splitting and thus prolongs the setting process of CA *** hydration products of cement form the major structural framework of hardened CA mortar and asphalt is a weak phase in the framework but improves the viscoelastic behavior of CA ***,asphalt emulsion should be used as much as possible on the condition that essential performance criterions of CA mortar are satisfied.

关键词： asphalt emulsion compressive strength CA mortar microstructure

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Modeling Flows over Gravel Beds by a Body Force Method

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Modeling Flows over Gravel Beds by a Body Force Method

第六届国际流体力学会议

作者： C.Zeng C.W.Li department of civil and {2. engineering The hong kong polytechnic university hong kong china

A Reynolds-averaged Navier-stokes equations（RANS） model using the body force method（BFM） has been developed to simulate open-channel flows over gravel *** momentum equation is modified by introducing the form drag as an extra body force term to represent the gravel-bed *** applying the body force within the roughness layer of the flow over small-scale roughness,it is found that the body force coefficient f rk varies inversely with the roughness length scale k *** method is robust,not sensitive to mesh resolution and is easily extended to deal with large scale roughness.

关键词： open-channel flows RANS modeling turbulent flows gravel beds body force method

Integration of GPS and Tiltmeters for Structure Monitoring

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Integration of GPS and Tiltmeters for Structure Monitoring

第三届中国卫星导航学术年会

作者： Wentao YANG Xiaoli DING Youlin XU department of Land Survey and Geo-informatics department of {2. and structural engineering The hong kong polytechnic university hung hom Kowloon hong kong

GPS has been studied extensively in recent years for monitoring struc-tural dynamics and *** technology offers a number of advantages in such *** is however well known that GPS observations are often af-fected by error sources such as the GPS signal multi-path effects especially on ob-servation sites where there are smooth reflective surfaces such as structure surfac-es on a building roof or the suspension cables on a cable stayed *** errors often render the GPS observations inaccurate and *** investigate in this research into a structure monitoring system where GPS and a tiltmeter are in-tegrated on a common platform so that the GPS and the tiltmeter measurements can be *** the error sources of GPS and the tiltmeters are different,the combined system makes good use of the complementary natures of the sensors to derive better monitoring *** integrated system,the data processing and analysis involved and some experimental results are presented.

关键词： GPS Tiltmeter Structure Monitoring

ADVANCED ANALYSIS FOR SEISMIC AND NON-SEISMIC DESIGN OF BUILDING STRUCTURES

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ADVANCED ANALYSIS FOR SEISMIC AND NON-SEISMIC DESIGN OF BUIL...

第六届海峡两岸及香港钢及组合结构技术研讨会—2.10

作者： Y.P.Liu and S.L.Chan~* department of civil and {2. engineering,The hong kong polytechnic university, hung Horn,Kowloon,hong kong,china

＜正＞Second-order analysis as a new and robust design method has been introduced in many modern codes such as drafted LRFD（2.10）,Eurocode-3（2.05） and HKSC（2.05） and becomes widely used in *** the traditional design method,which is based on the linearized structural response in conjunction with the effective length factor or the K-factor for stability checking,second-order or advanced analysis captures the true behavior in nonlinear range and considers the second-order effects,initial imperfections and material yielding in the process of *** to the superiority in theory,second-order analysis only needs the section design via the section capacity check rather than member design for safety and stability check and therefore avoids uncertainty in determination of effective *** change in design philosophy will likely make the traditional linear design method obsolete in the computer age *** is also noted that in last two decades many strong earthquakes occurred in the world which led to severe damage of numerous buildings and loss of thousands of *** to simplification in the linear theory,the lateral force method and model response spectrum analysis method have many limitations in seismic *** the contrary,the push-over and time history analysis,which are based on the same theoretical background as the second-order analysis,are believed to become more popular under the wide acceptance of performance-based seismic design,especially in meeting multiple performance *** this paper,the basic theoretical framework of second-order analysis for conventional structural design is briefly introduced and this method is extended to performance-based seismic design with the consideration of geometrical change and material ***,the proposed second-order/advanced analysis can be applied to seismic and non-seismic design of building structures.

关键词： Second-order Analysis Advanced Analysis Time History Analysis Performance-based Seismic Design NIDA

An Improved Golden Jackal Optimization Algorithm Based on Multi-strategy Mixing for Solving engineering Optimization Problems

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Journal of Bionic engineering 2024年第2期21卷 1092-1115页

作者： Jun Wang Wen-chuan Wang Kwok-wing Chau Lin Qiu Xiao-xue Hu hong-fei Zang Dong-mei Xu College of Water Resources North China University of Water Resources and Electric PowerZhengzhou450046People’s Republic of China department of civil and Environmental {2. The Hong Kong Polytechnic UniversityHong KongPeople’s Republic of China

Nowadays,optimization techniques are required in various engineering domains to find optimal solutions for complex *** a result,there is a growing tendency among scientists to enhance existing nature-inspired algorithms using various evolutionary strategies and to develop new nature-inspired optimization methods that can properly explore the feature *** recently designed nature-inspired meta-heuristic,named the Golden Jackal Optimization(GJO),was inspired by the collaborative hunting actions of the golden jackal in nature to solve various challenging ***,like other approaches,the GJO has the limitations of poor exploitation ability,the ease of getting stuck in a local optimal region,and an improper balancing of exploration and *** overcome these limitations,this paper proposes an improved GJO algorithm based on multi-strategy mixing(LGJO).First,using a chaotic mapping strategy to initialize the population instead of using random parameters,this algorithm can generate initial solutions with good diversity in the search ***,a dynamic inertia weight based on cosine variation is proposed to make the search process more realistic and effectively balance the algorithm's global and local search ***,a position update strategy based on Gaussian mutation was introduced,fully utilizing the guidance role of the optimal individual to improve population diversity,effectively exploring unknown regions,and avoiding the algorithm falling into local *** evaluate the proposed algorithm,2. mathematical benchmark functions,CEC-2.19 and CEC2.2. tests are *** results are compared to high-quality,well-known optimization *** results of the proposed method are compared from different points of view,including the quality of the results,convergence behavior,and *** superiority and high-quality performance of the proposed method are demonstrated by comparing the ***,to demonstrate

关键词： Golden jackal optimization Chaotic mapping Dynamic inertia weight Dimensional Gaussian variation Muskingum