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The long-span suspension bridge has suffered from multiple failures of restraints such as supports, dampers, and expansion joints due to excessive accumulated displacement at the girder end. To investigate the main girders’ characteristics in the longitudinal motion of these bridges and the influence of the restraint device on the longitudinal displacement, the motion characteristics were first analyzed based on the measured displacement data of a certain bridge’s main girder; a dynamic finite element model of the bridge’s random traffic flow was then established based on the measured WIM data; combined with the girder end displacement monitoring data, the Euclidean distance was used to verify the correctness and rationality of the proposed model; finally, the model is used to discuss the influence of restraint devices (i.e., viscous dampers and supports) on the main girder in the longitudinal direction. The results show that dynamic loads (such as vehicles and wind) are the principal reasons for huge accumulated travel at the girder end; The viscous damper can effectively control the longitudinal movement; in a certain range, the larger the damping index, the better the control effect of the damper; meanwhile, the friction coefficient of the support also affects the longitudinal motion, but the effect is limited. When the friction coefficient is ≤ 0.03, the girder end’s cumulative displacement gradually decreases with the increasing friction coefficient, and compared to the damping index, the friction coefficient plays a major controlling role in the girder end displacement; when the friction coefficient is >0.03, the damping index plays a major controlling role in the girder end displacement.

Simple Summary: Apostichopus japonicus is a temperate marine invertebrate and an economically important aquatic echinoderm species in China. As a benthic organism, sea cucumbers feed on small benthic particulate matter and are easily affected by pollutants. Therefore, for conservation purposes, it is important to elucidate the effects of specific pollutants on these animals. Bisphenol A (BPA) has been identified as an endocrine disruptor that functions as an estrogen analog and typically causes reproductive toxicity by interfering with the endocrine system. We identified the G protein-coupled estrogen receptor 1 in A. japonicus and found that both BPA and estradiol could activate the estrogen-receptor-mediated mitogen-activated protein kinase signaling pathway. Using biological approaches, we have confirmed the estrogen-analog bioactivity of BPA on sea cucumbers by direct interaction with the estrogen receptor. We also determined that BPA affects the reproduction of sea cucumbers by metabolic disruption in ovary tissue. The sea cucumber, Apostichopus japonicus, is a marine benthic organism that feeds on small benthic particulate matter and is easily affected by pollutants. Bisphenol A (BPA, 4,4′-isopropylidenediphenol) has been identified as an endocrine disruptor. It is ubiquitously detectable in oceans and affects a variety of marine animals. It functions as an estrogen analog and typically causes reproductive toxicity by interfering with the endocrine system. To comparatively analyze the reproductive effects of estradiol (E2) and BPA on sea cucumbers, we identified a G protein-coupled estrogen receptor 1 (GPER1) in A. japonicus and investigated its effects on reproduction. The results showed that BPA and E2 exposure activated A. japonicus AjGPER1, thereby mediating the mitogen-activated protein kinase signaling pathways. High-level expression of AjGPER1 in the ovarian tissue was confirmed by qPCR. Furthermore, metabolic changes were induced by 100 nM (22.83 μg/L) BPA exposure in the ovarian tissue, leading to a notable increase in the activities of trehalase and phosphofructokinase. Overall, our findings suggest that AjGPER1 is directly activated by BPA and affects sea cucumber reproduction by disrupting ovarian tissue metabolism, suggesting that marine pollutants pose a threat to the conservation of sea cucumber resources. [ABSTRACT FROM AUTHOR]