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life-cycle failure probability analysis of deteriorated RC bridges under multiple hazards of earthquakes and strong winds

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Earthquake Engineering and Engineering Vibration 2022年第3期21卷 811-823页

作者： Zheng Xiaowei li Hongnan Jiangsu Key Laboratory of Environmental Impact and Structural Safety in Engineering School of Mechanics and Civil EngineeringChina University of Mining and TechnologyXuzhou 221116China State Lab.of Coastal and Offshore Engineering Faculty of Infrastructure EngineeringDalian University of TechnologyDalian 116024China

Engineering structures may be exposed to one or more extreme hazards during their life-cycles.Current structural design specifications usually treat multiple hazards separately in designing structures and there is a limited probabilistic basis on extreme load combinations.Additionally,the performance of engineering structures will be deteriorated by the aggressive environments during their service periods,such as chloride attack,concrete carbonation,and wind-induced fatigue.This study presents a probabilistic methodology to assess the time-dependent failure probability of RC bridges with chloride-induced corrosion under the multiple hazards of earthquakes and strong winds.The loss of cross-section area of reinforcements and the reduction in strength of reinforcing steel and concrete cover induced by the chloride attack are considered.Moreover,the Poisson model is employed to obtain the occurrence probabilities of the individual and concurrent earthquake and strong wind events.The convolution integral is used to determine the joint probability distribution of combined load effects under simultaneous earthquakes and strong winds.Numerical results indicate that the structural failure probability under multiple hazards increases significantly during the bridge′s life-cycle due to the chloride corrosion effect.The contribution of each hazard event on the total structural failure probability varies with time.Thus,neglecting the combined influences of multiple hazards and chloride-induced corrosion may bring erroneous predictions in failure probability estimates of RC bridges.

关键词： life-cycle multihazard chloride occurrence model failure probability

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Seismic response of large-span spatial structures under multi-support and multidimensional excitations including rotational components

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Earthquake Engineering and Engineering Vibration 2021年第1期20卷 141-159页

作者： Zhang Jie li Hongnan li Chao State Key Laboratory of Coastal and Offshore Engineering Faculty of Infrastructure EngineeringDalian University of TechnologyDalian 116024China School of Civil Engineering Shenyang Jianzhu UniversityShenyang 110168China

To achieve rational and precise seismic response predictions of large span spatial structures(LSSSs),the inherent non-uniformity and multidimensionality characteristics of earthquake ground motions should be properly taken into consideration.However,due to the limitations of available earthquake stations to record seismic rotational components,the effects of rocking and torsional earthquake components are commonly neglected in the seismic analyses of LSSSs.In this study,a newly developed method to extract the rocking and torsion components at any point along the area of a deployed dense array from the translational earthquake recordings is applied to obtain the rotational seismic inputs for a LSSS.The numerical model of an actual LSSS,the Dalian International Conference Center(DICC),is developed to study the influences of multi-support and multidimensional excitations on the seismic responses of LSSSs.The numerical results reveal that the non-uniformity and multidimensionality of ground motion input can considerably affect the dynamic response of the DICC.The specific degree of influence on the overall and local structural displacements,deformations and forces are comprehensively investigated and discussed.

关键词： large-span spatial structures seismic responses multi-support multidimensional rotational components

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Market-based control strategy for long-span structures considering the multi-time delay issue

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Earthquake Engineering and Engineering Vibration 2017年第1期16卷 153-164页

作者： li Hongnan Song Jianzhu li Gang School of Civil Engineering Liaoning Collaborative Innovation Center for Engineering Disaster Prevention and MitigationDalian University of TechnologyDalian 116024China

To solve the different time delays that exist in the control device installed on spatial structures, in this study, discrete analysis using a 2N precise algorithm was selected to solve the multi-time-delay issue for long-span structures based on the market-based control （MBC） method. The concept of interval mixed energy was introduced from computational structural mechanics and optimal control research areas, and it translates the design of the MBC multi-time-delay controller into a solution for the segment matrix. This approach transforms the serial algorithm in time to parallel computing in space, greatly improving the solving efficiency and numerical stability. The designed controller is able to consider the issue of time delay with a linear controlling force combination and is especially effective for large time-delay conditions. A numerical example of a long-span structure was selected to demonstrate the effectiveness of the presented controller, and the time delay was found to have a significant impact on the results.

关键词： market based control multi-time delay interval mixed energy 2N precise algorithm discrete system

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Seismic performance evaluation of large-span offshore cable-stayed bridges under non-uniform earthquake excitations including strain rate effect

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Science China(Technological Sciences) 2020年第7期63卷 1177-1187页

作者： li Chao li Hongnan ZHANG Hao SU JunSheng li RouHan DING YiMing State Key Laboratory of Coastal and Offshore Engineering Faculty of Infrastructure EngineeringDalian University of TechnologyDalian 116024China School of Civil Engineering Shenyang Jianzhu UniversityShenyang 110168China Key Laboratory of Coast Civil Structure Safety of Ministry of Education Tianjin UniversityTianjin 300350China

This paper presents a novel and precise seismic performance evaluation method for large-span offshore cable-stayed(LSOCS)bridge by considering the strain rate effect of RC materials and the spatial variation effect of seafloor seismic motions. Threedimensional finite element(FE) model of a LSOCS bridge located in the southeast coast of China is constructed in the ABAQUS platform. The non-uniform ground motions at the offshore site beneath the bridge are stochastically simulated and used as seismic inputs. Moreover, a subroutine for considering the rate-dependent properties of RC materials in a fiber-based beamcolumn element model is developed to account for the strain rate effect of RC materials in the nonlinear time-history analysis.The numerical results indicate that seismic responses and fragilities of the LSOCS bridge are both considerably affected by the non-uniform seafloor seismic motions and strain rate effect. The seismic performance evaluation approach presented in this paper can provide vital support for earthquake resistant design of LSOCS bridges.

关键词： large-span offshore cable-stayed bridges spatially varying seafloor seismic motions strain rate effect seismic fragility

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Simulation of multi-support depth-varying earthquake ground motions within heterogeneous onshore and offshore sites

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Earthquake Engineering and Engineering Vibration 2018年第3期17卷 475-490页

作者： li Chao li Hongnan Hao Hong Bi Kaiming Tian li State Key Laboratory of Coastal and Offshore Engineering Faculty of Infrastructure EngineeringDalian University of Technology School of Civil Engineering Shenyang Jianzhu University Center for Infrastructure Monitoring and Protection School of Civil and Mechanical EngineeringCurtin University School of Civil Engineering Guangzhou University School of Civil Engineering Shandong University

This paper presents a novel approach to model and simulate the multi-support depth-varying seismic motions（MDSMs） within heterogeneous offshore and onshore sites.Based on 1 D wave propagation theory,the three-dimensional ground motion transfer functions on the surface or within an offshore or onshore site are derived by considering the effects of seawater and porous soils on the propagation of seismic P waves.Moreover,the depth-varying and spatial variation properties of seismic ground motions are considered in the ground motion simulation.Using the obtained transfer functions at any locations within a site,the offshore or onshore depth-varying seismic motions are stochastically simulated based on the spectral representation method（SRM）.The traditional approaches for simulating spatially varying ground motions are improved and extended to generate MDSMs within multiple offshore and onshore sites.The simulation results show that the PSD functions and coherency losses of the generated MDSMs are compatible with respective target values,which fully validates the effectiveness of the proposed simulation method.The synthesized MDSMs can provide strong support for the precise seismic response prediction and performance-based design of both offshore and onshore large-span engineering structures.

关键词： seismic motion simulation onshore and offshore sites ground motion spatial variation depth-varying motions transfer function

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Rapid repair techniques for severely earthquake-damaged circular bridge piers with flexural failure mode

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Earthquake Engineering and Engineering Vibration 2017年第2期16卷 415-433页

作者： Sun Zhiguo li Hongnan Bi Kaiming Si Bingjun Wang Dongsheng Department of Disaster Prevention Engineering Institute of Disaster Prevention Faculty of Infrastructure Engineering Dalian University of Technology Centre for Infrastructural Monitoring and Protection School of Civil and Mechanical EngineeringCurtin University Institute of Road and Bridge Engineering Dalian Maritime University

In this study, three rapid repair techniques are proposed to retrofit circular bridge piers that are severely damaged by the flexural failure mode in major earthquakes. The quasi-static tests on three 1：2.5 scaled circular pier specimens are conducted to evaluate the efficiency of the proposed repair techniques. For the purpose of rapid repair, the repair procedure for all the specimens is conducted within four days, and the behavior of the repaired specimens is evaluated and compared with the original ones. A finite element model is developed to predict the cyclic behavior of the repaired specimens and the numerical results are compared with the test data. It is found that all the repaired specimens exhibit similar or larger lateral strength and deformation capacity than the original ones. The initial lateral stiffness of all the repaired specimens is lower than that of the original ones, while they show a higher lateral stiffness at the later stage of the test. No noticeable difference is observed for the energy dissipation capacity between the original and repaired pier specimens. It is suggested that the repair technique using the early-strength concrete jacket confined by carbon fiber reinforced polymer （CFRP） sheets can be an optimal method for the rapid repair of severely earthquake-damaged circular bridge piers with flexural failure mode.

关键词： rapid repair severely earthquake-damaged circular bridge piers flexural failure mode CFRP early-strengthconcrete

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Metastable face-centered cubic ruthenium-based binary alloy for efficient alkaline hydrogen oxidation electrocatalysis

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Journal of Energy Chemistry 2024年第5期92卷 207-215页

作者： Yunbo li Jianchao Yue Chaoyi Yang hongnan Jia Hengjiang Cong Wei Luo College of Chemistry and Molecular Sciences Wuhan UniversityWuhan 430072HubeiChina

Metastable nanostructured electrocatalyst with a completely different surface environment compared to conventional phase-based electrocatalyst often shows distinctive catalytic property.Although Ru-based electrocatalysts have been widely investigated toward hydrogen oxidation reaction(HOR)under alkaline electrolytes,these studies are mostly limited to conventional hexagonal-close-packed(hcp)phase,mainly arising from the lack of sufficient synthesis strategies.In this study,we report the precise synthesis of metastable binary RuW alloy with face-centered-cubic(fcc)phase.We find that the introduction of W can serve as fcc phase seeds and reduce the formation energy of metastable fcc-RuW alloy.Impressively,fcc-RuW exhibits remarkable alkaline HOR performance and stability with the activity of 0.67 mA cm_(Ru)^(-2)which is almost five and three times higher than that of hcp-Ru and commercial Pt/C,respectively,which is attributed to the optimized binding strength of adsorbed hydroxide intermediate derived from tailored electronic structure through W doping and phase engineering.Moreover,this strategy can also be applied to synthesize other metastable fcc-RuCr and fcc-RuMo alloys with enhanced HOR performances.

关键词： Hydrogen oxidation reaction Metastable phase Face-centered cubic(fcc) Ru Phase engineering

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Apparent velocity estimation with P-SV ratio method

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Earthquake Engineering and Engineering Vibration 2011年第3期10卷 393-402页

作者： liu Yuewei li Hongnan Faculty of Infrastructure Engineering Dalian University of Technology Dalian 116024 China

The apparent velocity of the incident wave is an important parameter for simulating rotational ground motion with theoretical methods, but it is difficult to estimate effectively when there is only a single record. This paper discusses a P-SV ratio method based on elastodynamic theory in a multi-layer isotropic elastic half space. The apparent velocities of four earthquakes in the SMART1 array are calculated with this method. The result is close to a method that uses travel time analysis. Furthermore, the factors that impact the apparent velocity and equivalent incident angle are considered according to records from the Chi-Chi earthquake. There is no obvious relationship between the equivalent incident angle and epicenter distance. However, the equivalent incident angle is obviously dependent on the site conditions.

关键词： apparent velocity P-SV ratio equivalent incident angle rotational ground motion

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Treatment patterns and clinical outcomes in patients with metastatic breast cancer treated with palbociclib-based therapies:real-world data in the Han population

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Chinese Medical Journal 2022年第14期135卷 1734-1741页

作者： hongnan Mo Fei Ma Qing li Pin Zhang Peng Yuan Jiayu Wang Yang Luo Ruigang Cai Qiao li Binghe Xu Department of Medical Oncology National Cancer CenterNational Clinical Research Center for CancerCancer HospitalChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijing 100021China

Background:This study aimed to reveal the treatment patterns and clinical outcomes of diverse palbociclib-based regimens in Han patients with estrogen receptor-positive(ER+)metastatic breast cancer in routine clinical practice.Methods:The clinical data of patients with ER+metastatic breast cancer treated with palbociclib were collected from the National Cancer Center database.The efficacy profile of palbociclib in this Han population was evaluated,especially for various combination regimens.The efficacy of palbociclib-based therapy in patients with prior everolimus treatment was also assessed.Results:A total of 186 patients from 89 cities in 18 provinces in China were enrolled.The median progression-free survival(PFS)was similar among different palbociclib-combined groups(P=0.566):10.0 months(95%confidence interval[CI]3.8-16.1)in the+exemestane group,9.7 months(95%CI 6.3-13.1)in the+letrozole group,7.8 months(95%CI 5.5-10.2)in the+fulvestrant group,7.2 months(95%CI 3.2-11.3)in the+toremifene group,and 6.1 months(95%CI 1.2-11.0)in the+anastrozole group.Thirty-four patients(18.3%)had received everolimus for their metastatic disease before the prescription of palbociclib.The disease control rate was significantly lower in patients who had received previous everolimus than in the everolimus-naïve group(50.0%vs.82.2%,Plimus had significantly worse PFS than those in the everolimus-naïve group(3.4 months vs.8.8 months,P=0.001).After propensity score matching,patients pre-treated with everolimus had similar PFS(4.4 months,95%CI 0.5-8.2)compared with everolimus-naïve patients(6.1 months,95%CI 4.7-7.5,P=0.439).Conclusions:Various palbociclib-based regimens have promising efficacy in ER+metastatic breast cancer in real-world settings,even in patients who had been pre-treated with everolimus.

关键词： Metastatic breast cancer Palbociclib Progression-free survival Real-world data

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Correlation of ADC value with pathologic indexes in colorectal tumor homografts in Balb/c mouse

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Chinese Journal of Cancer Research 2014年第4期26卷 444-450页

作者： Xiaojun li hongnan Jiang Jinliang Niu Ying Zheng Department of Radiology the 2nd Hospital of Shanxi Medical University Department of Breast Surgery the 2nd Hospital of Shanxi Medical University

Objective： Noninvasive diffusion-weighted magnetic resonance imaging （DWI） is a well-studied MR imaging technique for quantifying water diffusion especially in tumor area. The correlation between apparent diffusion coefficient （ADC） value and apoptosis or proliferation is not clear by now. This study aimed to investigate whether DWI-ADC value could be used as an imaging marker related with pathologic indexes of tumors. Methods： A total of 3 0 Balb/c mice with HT2 9 colorectal carcinoma were subjected to DWI and histologic analysis. The percentage of ADC changes and the apoptotic and proliferating indexes were calculated at predefined time points. Kolmogorov-Smirnov distances were considered to determine whether the percentage of ADC changes, and the apoptotic and proliferating indexes were normally distributed. An independent-samples t-test was used to analyze the difference between apoptotic and proliferating indexes in the two groups. Results： There was a statistically significant difference in proliferating index between the radiotherapy and control groups （mean proliferating index： 49.27% vs. 83.09%）, and there was a statistically significant difference in apoptotic index between the two groups （mean apoptotic index： 37.7% vs. 2.71%）. A significant positive correlation was found between the percentage of ADC changes of the viable tissue and apoptotic index. Pearson＇s correlation coefficient was 0.655 （P=0.015）. A significant negative correlation was found between the percentage of ADC changes of the viable tissue and ki-67 proliferation index. Pearson＇s correlation coefficient was 0.734 （P〈0.001）. Conclusions： Our results suggest that ADC proliferating indexes in colorectal carcinoma. value may be used in measurement of cell apoptotic and

关键词： Diffusion-weighted magnetic resonance imaging （DWI） apparent diffusion coefficient （ADC） apoptosis proliferation HT29

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