Long-term assimilation wetlands in coastal Louisiana: Review of monitoring data and management

Along with building slender and longer span structures, vibration serviceability becomes more important considerations in bridge design and maintenance. In this study, vibration serviceability and deflection limit for long span cable bridges are investigated using long-term monitoring data such as accelerations and displacements of bridges. Exampled bridges are Yi Sun-Sin Grand Bridge (suspension bridge, main span length=1,545m) and 2nd Jindo Grand Bridge (cable stayed bridge, main span length=344m). Long-term data are analyzed and compared with various design codes, guidelines, and other research results. Probability of exceedance are calculated for each criterion. Regarding on deflection limits, Korean Bridge Design Code (Limit State Design) specifies L/400 and L/350 for cable stayed and suspension bridges, respectively. Saadeghvaziri suggested deflection limit based on natural frequency, acceleration limit of 0.5 m/s² and vehicle speed. Various human comfort criteria on vibration are also applied including ISO standards. The results of this study are expected to be useful reference for the design, the proper planning and deflection review of the long span cable bridges around the world. Further researches are required to find the optimum deflection or vibration criteria for long span bridge and their effects on bridge clearance and elevation.

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Proposed evaluation methods for vibration serviceability of long span cable bridges

IABSE Congress, Christchurch 2021: Resilient technologies for sustainable infrastructure ◽

10.2749/christchurch.2021.0327 ◽

2021 ◽

Author(s):

E.-S. Hwang ◽

M. T. Hwang ◽

D. Y. Kim ◽

K. J. Park

Keyword(s):

Heavy Traffic ◽

Damping Ratio ◽

Flexible Structures ◽

Evaluation Methods ◽

Monitoring Data ◽

Long Span ◽

Vibration Serviceability ◽

Long Term Monitoring ◽

Term Monitoring

Vibration serviceability becomes more important considerations in design and maintenance, especially for slender and flexible structures such as long span cable bridges. In this study, various evaluation methods for vibration serviceability for long span cable bridges are proposed. These methods are based on short and long-term monitoring data such as accelerations and displacements of bridges. Proposed methods include (1) method of evaluating vibration amplitude based on Reiher-Meister curves, (2) method of evaluating variations in natural frequencies and damping ratio,(3) method of weighted rms(root-mean-square) acceleration based on ISO 2631-1, and (4) probabilistic analysis using long-term monitoring data. These methods are applied to example cable bridge and cases of normal traffic, heavy traffic, windy condition and sudden abnormal vibration are considered. The results of this study are expected to be implemented to real bridge monitoring system for real-time and periodic evaluation of vibration serviceability.

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Forecasting structural strains from long-term monitoring data of a traditional Tibetan building

Structural Control and Health Monitoring ◽

10.1002/stc.2300 ◽

2018 ◽

Vol 26 (1) ◽

pp. e2300 ◽

Cited By ~ 2

Author(s):

Na Yang ◽

Xiaobin Bai

Keyword(s):

Monitoring Data ◽

Long Term Monitoring ◽

Term Monitoring

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Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

San Francisco Estuary and Watershed Science ◽

10.15447/sfews.2021v19iss3art6 ◽

2021 ◽

Vol 19 (3) ◽

Author(s):

Vanessa Tobias ◽

Keyword(s):

San Francisco ◽

Water Clarity ◽

Ecological Monitoring ◽

Monitoring Data ◽

Delta Smelt ◽

Individual Based Simulation ◽

The Relationship ◽

True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are the result of changing water clarity affecting catchability.

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Simulated Fishing to Untangle Catchability and Availability in Fish Abundance Monitoring

10.20944/preprints202002.0177.v3 ◽

2021 ◽

Author(s):

Vanessa Tobias

Keyword(s):

San Francisco ◽

Water Clarity ◽

Ecological Monitoring ◽

Monitoring Data ◽

Delta Smelt ◽

Individual Based Simulation ◽

The Relationship ◽

True Population

In fisheries monitoring, catch is assumed to be a product of fishing intensity, catchability, and availability, where availability is defined as the number or biomass of fish present and catchability refers to the relationship between catch rate and the true population. Ecological monitoring programs use catch per unit of effort (CPUE) to standardize catch and monitor changes in fish populations; however, CPUE is proportional to the portion of the population that is vulnerable to the type of gear that is used in sampling, which is not necessarily the entire population. Programs often deal with this problem by assuming that catchability is constant, but if catchability is not constant, it is not possible to separate the effects of catchability and population size using monitoring data alone. This study uses individual-based simulation to separate the effects of changing environmental conditions on catchability and availability in environmental monitoring data. The simulation combines a module for sampling conditions with a module for individual fish behavior to estimate the proportion of available fish that would escape from the sample. The method is applied to the case study of the well-monitored fish species Delta Smelt (Hypomesus transpacificus) in the San Francisco Estuary, where it has been hypothesized that changing water clarity may affect catchability for long-term monitoring studies. Results of this study indicate that given constraints on Delta Smelt swimming ability, it is unlikely that the apparent declines in Delta Smelt abundance are due to an effect of changing water clarity on catchability.

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Long-term monitoring data logs of a recirculating artificial seawater based colonial ascidian aquaculture

Data in Brief ◽

10.1016/j.dib.2021.107372 ◽

2021 ◽

Vol 38 ◽

pp. 107372

Author(s):

Marta K. Wawrzyniak ◽

Lluìs Albert Matas Serrato ◽

Simon Blanchoud

Keyword(s):

Artificial Seawater ◽

Monitoring Data ◽

Colonial Ascidian ◽

Long Term Monitoring ◽

Term Monitoring

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