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Frontiers of Structural and Civil Engineering 2024年第7期18卷 1117-1133页

作者： pengfei dou Hao LIU Chengshun XU Jinting WANG Yilong SUN Xiuli DU Department of Hydraulic Engineering Tsinghua UniversityBeijing 100084China Key Laboratory of Urban Security and Disaster Engineering of the Ministry of Education Beijing University of TechnologyBeijing 100124China

This study investigates the seismic response and failure mode of a pile-structure system in a liquefiable site by employing a numerical simulation model combined with the shaking-table results of a soil-pile-structure dynamic *** pile and soil responses obtained from the numerical simulations agreed well with the experimental *** slopes of the dynamic shear-stress-shear-strain hysteretic curves at different positions also exhibited a decreasing trend,indicating that the shear strength of the soil in all parts of the foundation *** peak acceleration of the soil and pile was not clearly amplified in the saturated sand layer but appeared to be amplified in the top *** maximum bending moments appeared in the middle and lower parts of the pile shaft;however,the shear forces at the corresponding positions were not *** can be observed from the deformation mode of the pile-group foundation that a typical bending failure is caused by an excessive bending moment in the middle of the pile shaft if the link between the pile top and cap is articulated,and sufficient attention should be paid to the bending failure in the middle of the pile shaft.

关键词： numerical simulation soil liquefaction pile foundation shaking-table experiment seismic responses failure model

Analysis on kinematic and inertial interaction in liquefiable soil-pile-structure dynamic system

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Earthquake Engineering and Engineering Vibration 2023年第3期22卷 601-612页

作者： Xu Chengshun Liu Hao dou pengfei Wang Jinting Chen Su Du Xiuli Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100124China Department of Hydraulic Engineering Tsinghua UniversityBeijing 100084China

The dynamic pile-soil interaction in a liquefied site was investigated by means of numerical simulation and shaking table tests in this *** on the results from the shaking table experiment,the cross-correlation analysis of the soil displacement-pile bending moment and superstructure acceleration-pile bending moment was performed to study the influence of kinematic interaction and inertial interaction on the seismic response of piles.A relatively reasonable and accurate finite difference numerical analysis model of liquefiable soil-pile group-superstructure dynamic system was *** numerical simulation,the understanding of kinematic interaction and inertial interaction in the shaking table test was *** mass,damping and period of the superstructure were selected as variables to carry out parameter analysis to further study the influence of inertial interaction on the pile-structure failure *** results show that the influence of kinematic interaction on the pile was much greater than that of inertial *** mass of the superstructure was the most important parameter of inertial interaction,and dynamic characteristics of the superstructure also had an effect on inertial *** effect of inertial interaction on the part near the pile tip was more significant,indicating that the failure near the pile tip is closely related to inertial interaction.

关键词： shaking table experiments pile-supported structures dynamic response liquefaction lateral constraint instability

Seismic response comparison and sensitivity analysis of pile foundation in liquefiable and non-liquefiable soils

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Earthquake Engineering and Engineering Vibration 2023年第1期22卷 87-104页

作者： Jia Kemin Xu Chengshun Du Xiuli Cui Chunyi dou pengfei Song Jia Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of Technology Beijing 100124China Transportation Engineering College Dalian Maritime University Dalian 116026China North China University of Technology School of Civil Engineering Beijing 100144China

Case history investigations have shown that pile foundations are more critically damaged in liquefiable soils than non-liquefiable *** study examines the differences in seismic response of pile foundations in liquefiable and non-liquefiable soils and their sensitivity to numerical model parameters.A two-dimensional finite element(FE)model is developed to simulate the experiment of a single pile foundation centrifuge in liquefiable soil subjected to earthquake motions and is validated against real-world test *** differences in soil-pile seismic response of liquefiable and non-liquefiable soils are ***,the first-order second-moment method(FOSM)is used for sensitivity analysis of the seismic *** results show significant differences in seismic response for a soil-pile system between liquefiable and non-liquefiable *** seismic responses are found to be significantly larger in liquefiable soil than in non-liquefiable ***,the pile bending moment was mainly affected by the kinematic effect in liquefiable soil,while the inertial effect was more significant in non-liquefiable *** controlling parameters of seismic response were PGA,soil density,and friction angle in liquefiable soil,while the pile bending moment was mainly controlled by PGA,the friction angle of soil,and shear modulus of loose sand in non-liquefiable soil.

关键词： liquefiable non-liquefiable finite element analysis pile foundation seismic response sensitivity analysis

A Study on the Factors influencing insulin resistance in obese adolescents

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Journal of Nanjing Medical University 2008年第6期22卷 391-394页

作者： Yongmei Jin pengfei dou Departments of Pediatrics The First Affiliated Hospital of Anhui Medical University Hefei 230032 Anhui Province China

Objective： To explore the factors influencing insulin resistance in obese Chinese children. Methods： We randomly selected 53 children with uncomplicated obesity between 9 to14 years of age, and 29 normal healthy children, matched for age and sex. Anthropometric and plasma biochemical variables（including lipid profiles, glucose and insulin） were measured using standard methods. We calculated insulin resistance（IR） index using homeostasis model assessment（HOMA） methods and measured plasma high-sensitivity C-reactive protein（hs-CRP） levels using nephelometric methods. All statistical analyses were conducted using the statistical package SPSS. Results： Levels of fasting serum insulin, hs-CRP, total cholesterol（TC）, low density lipoproteins cholesterol（LDL-C） and IR index were higher in obese children than in controls, while high-density lipoprotein cholesterol（HDL-C） values were lower in the obese children. There was no significant difference in levels of fasting blood glucose between the two groups. HOMA-IR was used as the dependent variable in multivariate regression analysis. Significant independent predictors for insulin resistance adjusted for waist/hip ratio, diastolic pressure （DBP）, BMI, triglycerides and HDL-C level were waist circumference（WC）, weight and systolic pressure（SBP）. Conclusion： Waist circumference, weight and SBP are predictors of insulin resistance syndrome in Chinese adolescents

关键词： Obesity Insulin resistance Adolescents

Simulation of Hydrodynamic Performance of Drag and double Reverse Propeller Podded Propulsors

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Journal of Marine Science and Application 2016年第1期15卷 16-27页

作者： Chunyu Guo pengfei dou Tao Jing Dagang Zhao School of Shipbuilding Engineering Harbin Engineering University Harbin 150001 China

The unsteady performance of drag and double reverse propeller podded propulsors in open water was numerically simulated using a computational fluid dynamics （CFD） method. A moving mesh method was used to more realistically simulate propulsor working conditions, and the thrust, torque, and lateral force coefficients of both propulsors were compared and analyzed. Forces acting on different parts of the propulsors along with the flow field distribution of steady and unsteady results at different advance coefficients were compared. Moreover, the change of the lateral force and the difference between the abovementioned two methods were mainly analyzed. It was shown that the thrust and torque results of both methods were similar, with the lateral force results having the highest deviation

关键词： podded propulsor propeller lateral force computational fluid dynamics (CFD) hydrodynamic performance moving mesh method

Experimental Study on Hydrodynamics of L-type Podded Propulsor in Straight-ahead Motion and Off-Design Conditions

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Journal of Marine Science and Application 2017年第1期16卷 48-59页

作者： Dagang Zhao Chunyu Guo Yumin Su pengfei dou Tao Jing School of Shipbuilding Engineering Harbin Engineering University Harbin 150001 China National Engineering Research Center of Shanghai ship Design Technology Shanghai 200080 China

Experimental tests were conducted to evaluate the hydrodynamic performance of an L-type podded propulsor in straight-ahead motion and off-design conditions using an open-water measuring instrument developed by the authors for podded propulsors, a ship model towing tank, and under water particle image velocimetry （PIV） measurement systems. Under the three types of conditions, the main parameters of an L-type podded propulsor were measured, including the propeller thrust and torque, as well as the thrust, side force, and moment of the whole pod *** addition, the flow field on the section between the propeller and the strut was analyzed. Experimental results demonstrate that the dynamic azimuthing rate and direction and the turning direction affect the forces on the propeller and the whole pod unit. Forces are asymmetrically distributed between the left and right azimuthing directions because of the effect of propeller rotation. The findings of this study provide a foundation for further research on L-type podded propulsors.

关键词： L-type podded propulsor off-design condition flow field particle image velocimetry propeller hydrodynamic experimental test

局部液化夹层场地土-结接触特性对地下结构地震响应的影响研究

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岩石力学与工程学报 2023年第S1期42卷 3643-3653页

作者：闫冠宇许成顺张梓鸿宋佳豆鹏飞北京工业大学城市与工程安全减灾教育部重点实验室北京100124 北方工业大学土木工程学院北京100144 清华大学水利水电工程系北京100084

当地下结构穿越液化土层,场地液化可能会对结构的动力响应产生影响。基于已开展的局部液化夹层场地地下结构离心机振动台模型试验,建立二维局部液化场地土-结构动力相互作用的有限元模型。计算模型考虑砂土液化后易产生剪切大变形的特... 详细信息

当地下结构穿越液化土层,场地液化可能会对结构的动力响应产生影响。基于已开展的局部液化夹层场地地下结构离心机振动台模型试验,建立二维局部液化场地土-结构动力相互作用的有限元模型。计算模型考虑砂土液化后易产生剪切大变形的特点以及饱和两相介质与结构接触的非线性特性,通过与试验结果对比,验证数值模型的正确性,进一步分析土-结构接触非线性特性对结构地震响应的影响。研究结果表明:孔压的增长是由于地震作用的累积效应;近场砂土由于土结相互作用的存在超孔压比上升的更快,且由于土与结构变形不协调而更易消散;对于局部液化夹层场地,土结捆绑接触会放大结构的地震响应,随着地震动强度的增大,砂土层液化程度提高,场地非线性特性增强,土结刚度差异增大,土结界面采用捆绑接触所带来的误差越大,故应合理考虑土结界面接触非线性问题。

关键词：土力学液化场地离心机振动台试验土-结界面模型有限元分析

非液化土-群桩基础-结构体系相互作用动力响应振动台试验研究

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建筑结构学报 2022年第5期43卷 185-194,204页

作者：许成顺豆鹏飞杜修力陈苏李霞北京工业大学城市与工程安全减灾教育部重点实验室北京100124 中国地震局地球物理研究所北京100081 北京城建设计发展集团股份有限公司北京100037

为深入研究非液化场地中桩-结构体系地震响应和土-结构动力相互作用问题,进行了含有一定深度的松砂层非液化场地土-结构体系动力相互作用大型振动台试验,分析非液化场地和群桩基础的加速度地震响应特征,并对土体侧向变形规律以及桩基弯... 详细信息

为深入研究非液化场地中桩-结构体系地震响应和土-结构动力相互作用问题,进行了含有一定深度的松砂层非液化场地土-结构体系动力相互作用大型振动台试验,分析非液化场地和群桩基础的加速度地震响应特征,并对土体侧向变形规律以及桩基弯矩分布进行了分析。结果表明:当输入0.05g拍波时,土体与桩基对加速度反应表现出放大作用,且距离结构较远处土体对加速度放大作用更加明显;当输入0.3g汶川地震卧龙台地震记录时,加速度只在远离桩基的土体中加速度反应有一定放大;桩身最大弯矩均超过60 N·m,并且桩基弯矩幅值呈现出桩顶弯矩小(靠近桩顶处)、下部弯矩大(靠近桩端处)的规律,且在土层交界面附近弯矩存在突变;上部结构加速度反应自上而下有一定程度的减小,地震动Arias强度值减小明显,刚性场地上的结构地震动Arias强度是位于土体上结构的3~4倍,说明土体的耗能作用明显。

关键词：群桩基础非液化场地振动台试验动力响应

淀粉/钠基蒙脱土/聚丙烯酸高吸水树脂的制备研究

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橡塑技术与装备 2019年第20期45卷 40-47页

作者：豆鹏飞长庆油田公司

本文以丙烯酸(AA)、淀粉等为原料,复合钠基蒙脱土,利用水溶液聚合法,合成制备一种复合型高吸水树脂油田堵漏剂,并在此基础上探索影响吸水树脂吸水性能的因素。最佳吸水性能的工艺条件为:70℃条件下调单体中和度至70%、N,N’-亚甲基双丙... 详细信息

本文以丙烯酸(AA)、淀粉等为原料,复合钠基蒙脱土,利用水溶液聚合法,合成制备一种复合型高吸水树脂油田堵漏剂,并在此基础上探索影响吸水树脂吸水性能的因素。最佳吸水性能的工艺条件为:70℃条件下调单体中和度至70%、N,N’-亚甲基双丙烯酰胺0.065 g、过硫酸钾为0.044 g,蒙脱土3 g。所得产品:吸水倍率251.3 g/g、吸盐倍率69.2 g/g。最佳吸盐水配方条件为:60℃条件下调单体中和度至75%、N,N’-亚甲基双丙烯酰胺0.075 g、过硫酸钾为0.049 g、蒙脱土3 g;所得产品:吸水倍率238.2 g/g、吸盐倍率81.5 g/g。样品吸水后为无色透明块状胶体,烘干粉碎后为淡黄色颗粒。

关键词：水溶液聚合法高吸水树脂吸盐倍率吸水倍率

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槲皮素分子印迹聚合物合成及识别研究

橡塑技术与装备 2018年第20期44卷 16-23页

作者：豆鹏飞长庆油田公司陕西榆林718100

以槲皮素(Quercetin)为模板分子,丙烯酰胺(AM)和4-乙烯基吡啶(4-VP)为双功能单体,三羟甲基丙烷三甲基丙烯酸酯(TRIM)为交联剂,采用沉淀聚合法制备槲皮素分子印迹聚合物(MIPs)并对其性能进行了考察。实验考察了致孔剂的体积、功能单体种... 详细信息

以槲皮素(Quercetin)为模板分子,丙烯酰胺(AM)和4-乙烯基吡啶(4-VP)为双功能单体,三羟甲基丙烷三甲基丙烯酸酯(TRIM)为交联剂,采用沉淀聚合法制备槲皮素分子印迹聚合物(MIPs)并对其性能进行了考察。实验考察了致孔剂的体积、功能单体种类以及功能单体比例等因素对槲皮素MIPs吸附容量和选择性的影响。实验结果表明:以40 mL致孔剂、1:1AM/4-VP混合功能单体采用沉淀聚合法制备的MIPs吸附容量达到6.93μmol/g,是传统本体聚合法制备的MIPs吸附量的3.08倍,并且此法制备的MIPs相比本体聚合法具有更好的特异性识别能力和分离能力,分离因子α达到4.33;本文还将制备的MIPs用作固相萃取(SPE)吸附剂,优化了固相萃取的实验条件并采用SPE的方式对实际油茶壳样品中的槲皮素进行分离富集,试验结果表明用MIPs固相萃取处理后的油茶壳提取液中槲皮素的含量能达到83%,说明了槲皮素分子印迹固相萃取对实际油茶壳样品中槲皮素具有较好的分离、纯化效果。

关键词：分子印迹聚合物沉淀聚合法选择性识别能力分离能力