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Field monitoring of differential frost heave in widened highway subgrade

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Research in Cold and Arid Regions 2021年第5期13卷 408-418页

作者： XuFeng Lu Feng Zhang kangwei tang DeCheng Feng School of Transportation Science and Engineering Harbin Institute of TechnologyHeilongjiang 150090HarbinChina

In cold regions,the widened subgrade could produce uneven frost heave that is detrimental to the *** study investigates the differential frost heave characteristics in a widened *** field monitoring system mainly consists of temperature,moisture,and displacement sensors and distributed optical fiber cables for strain *** monitoring results show that the cooling period in the subgrade is longer than the warming *** content in the subgrade changes significantly within 0−2 m below the subgrade surface but stabilizes within 2−5 *** maximum frost heave occurs from February to *** comparison,the existing subgrade has a longer freezing period and larger heave value,caused by the higher density and water content *** in the existing subgrade migrates into the new one after widening,leading to frost heave reduction in the existing ***,the traffic loads result in the consolidation of the new subgrade,thus reducing the heave value in the second *** the third year,the water supply from the existing subgrade facilitates the frost heave in the new *** tensile strain distributions obtained by the distributed optical fiber cables show that the maximum differential frost heave occurs at the joint between the existing and new *** differential frost heave gradually stabilizes after three ***,an improved frost heave prediction model is developed based on the segregation potential concept and monitoring results.

关键词： widened subgrade differential frost heave field monitoring distributed optical fiber strain sensing seasonally frozen region

Numerical simulation of electroosmosis in unsaturated compacted clay

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Research in Cold and Arid Regions 2021年第5期13卷 394-407页

作者： kangwei tang Feng Zhang DeCheng Feng GuanFu Wang School of Transportation Science and Engineering Harbin Institute of Technology73 Huanghe RoadHarbinHeilongjiang 150090China

The moisture content of a road subgrade in cold regions will increase after freeze-thaw cycles,resulting in subgrade strength and stiffness *** is widely used in treating saturated soft soils to decrease the moisture *** induced moisture migration during electroosmosis in unsaturated soil is much more complex than that of saturated soil because of a series of nonlinear changes in soil *** study first uses an exponential function to characterize the relationship between electroosmotic permeability and saturation ***,a one-dimensional model is developed to simulate the electroosmosis-induced moisture migration in unsaturated *** results show that electroosmosis reduces the saturation degree of the unsaturated soil,indicating that it can be applied to subgrade *** parameters such as soil pore size distribution coefficient,air entry value,and effective voltage significantly affect moisture *** properties of unsaturated soils are extremely important to the efficiency of electroosmosis.

关键词： electro-osmosis unsaturated clay moisture migration numerical simulation

A nonlinear interface structural damage model between ice crystal and frozen clay soil

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Research in Cold and Arid Regions 2021年第2期13卷 150-166页

作者： Sheng Shi Feng Zhang kangwei tang DeCheng Feng XuFeng Lu School of Transportation Science and Engineering Harbin Institute of TechnologyHeilongjiangHarbin 150090China State Key Laboratory of Road Engineering Safety and Health in Cold and High−Altitude Regions CCCC First Highway Consultants Co.Ltd.Xi'an 710075China

The shear properties of ice-frozen soil interface are important when studying the constitutive model of frozen soil and slope stability in cold regions. In this research, a series of cryogenic direct shear tests for ice-frozen clay soil interface were conducted. Based on experimental results, a nonlinear interface structural damage model is proposed to describe the shear properties of ice-frozen clay soil interface. Firstly, the cementation and friction structural properties of frozen soil materials were analyzed, and a structural parameter of the ice-frozen clay soil interface is proposed based on the cryogenic direct shear test results. Secondly, a structural coefficient ratio is proposed to describe the structural development degree of ice-frozen clay soil interface under load, which is able to normalize the shear stress of ice-frozen clay soil interface,and the normalized data can be described by the Duncan-Chang model. Finally, the tangent stiffness of ice-frozen clay soil interface is calculated, which can be applied to the mechanics analysis of frozen soil. Also, the shear stress of ice-frozen clay soil interface calculated by the proposed model is compared with test results.

关键词： ice-frozen clay soil interface cryogenic direct shear test structural coefficient ratio shear tangent stiffness cementation

Investigation on the properties of compacted silty clay subjected to electro-osmosis using bender element

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Research in Cold and Arid Regions 2023年第6期15卷 253-261页

作者： kangwei tang Chuang Lin Hao Wang WeiJun Qin DeCheng Feng Feng Zhang School of Transportation Science and Engineering Harbin Institute of Technology73 Huanghe RoadHarbinHeilongjiang 150090China Laboratoire Navier/CERMES Ecole des Ponts ParisTech6 et 8 Avenue Blaise PascalCite DescartesChamps-sur-Marne77455 Marne La Vallee Cedex 2France Key Laboratory of Transportation Industry for Highway Construction and Maintenance Technology in Seasonal Frozen Soil Areas(Changchun) 4887 Xinglong RoadChangchunJinlin 130102China

The moisture content of subgrade soil in seasonally frozen regions is often higher than its optimum value,leading to a decline in mechanical properties and a reduction in subgrade bearing ***-osmosis has shown promise as a technology for controlling subgrade moisture,but significant heterogeneity has also been observed in treated *** study investigates the impact of electro-osmosis on soil stiffness through a series of bender element tests of compacted *** effects of dry density and supply voltage on the performance of electroosmosis treatment and the layered structure and anisotropy of the soil were *** results show that electro-osmosis treatment increased the shear wave velocity of the soil by 140% compared to untreated saturated soil and by 70% compared to soil with optimum water *** has also been found that layered compaction of soil resulted in a layered structure,with electro-osmosis having a more prominent impact on soil near the cathode,resulting in a more pronounced layered ***,electro-osmosis was found to enhance soil anisotropy,particularly near the *** the dry density and voltage levels can help improve soil *** findings provide insights into the potential use of electro-osmosis in improving soil stiffness,which could benefit various engineering applications.

关键词： Subgrade soil Electro-osmosis Bender element Layered structure Anisotropy

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单向冻结条件下饱和粉质黏土的冻胀试验研究

建筑材料学报 2016年第5期19卷 926-932页

作者：马宏岩张锋冯德成唐康为哈尔滨工业大学交通科学与工程学院黑龙江哈尔滨150090 福州大学土木工程学院福建福州350116

在单向冻结条件下对饱和粉质黏土试件进行了6种工况下的室内冻胀试验研究.结果表明:冷端温度、压实度、温度梯度、上覆压力和补水条件是影响土体冻胀变形的关键因素;温度梯度、冷端温度和上覆压力与土体冻胀变形呈反比,压实度与土体冻... 详细信息

在单向冻结条件下对饱和粉质黏土试件进行了6种工况下的室内冻胀试验研究.结果表明:冷端温度、压实度、温度梯度、上覆压力和补水条件是影响土体冻胀变形的关键因素;温度梯度、冷端温度和上覆压力与土体冻胀变形呈反比,压实度与土体冻胀变形呈正比;冻胀率是表征土体冻胀敏感性的关键指标,与材料参数和冻结条件有关.最后,基于试验研究提出了用于指导工程应用的路基冻胀病害防治措施.

关键词：季节性冻土区粉质黏土冻胀变形温度场冻胀速率冻胀率冻胀控制

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模量不均匀路基上的沥青路面动力响应研究

土木工程学报 2018年第3期51卷 115-122页

作者：张锋臧宏阳冯德成林波唐康为哈尔滨工业大学黑龙江哈尔滨150090 中交公路规划设计院有限公司北京100088

为研究路基模量的不均匀对沥青路面动力响应的影响规律,首先采用便携式落锤弯沉仪(简称PFWD)对亚—雪公路路基模量分布进行现场测试,分析并总结路基模量的空间不均匀分布特征;进而考虑汽车车体的运动、轮胎的黏弹效应、沥青路面的黏弹... 详细信息

为研究路基模量的不均匀对沥青路面动力响应的影响规律,首先采用便携式落锤弯沉仪(简称PFWD)对亚—雪公路路基模量分布进行现场测试,分析并总结路基模量的空间不均匀分布特征;进而考虑汽车车体的运动、轮胎的黏弹效应、沥青路面的黏弹性能以及路基模量的不均匀特性,基于D'Alembert原理和黏弹性薄板振动理论,建立了重载汽车-路面-不均匀模量路基耦合动力学模型,并分析了路基不均匀特性、行车速度和后轴轴重对沥青路面动力响应的影响。计算结果表明,路基模量的不均匀性对路面动应变的影响显著。当汽车行驶通过路基不均匀模量区时,后轴产生的基层底应变幅值约为前轴的2倍;当后轴轴载由100k N增加至180k N,基层底应变幅值由62με增加到109με;随着行车速度从5km/h增加至80km/h,基层底部的拉应变幅值增加1.3倍,并逐渐趋于稳定;特别当路基不均匀模量幅值从40MPa降低到0、不均匀模量弦长由1m增加至4m,基层层底拉应变幅的增幅分别可达26%和23%。

关键词：道路工程路基不均匀模量沥青路面动力响应车-路耦合动力学模型

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弱作用基有机发光材料

有机化学 2024年第8期44卷 2453-2468页

作者：沈钇灼罗康为徐清洋张鉴予孙景志张浩可唐本忠浙江大学高分子科学与工程学系高分子合成与功能构造教育部重点实验室浙江大学杭州国际科创中心浙江-以色列自组装功能材料联合实验室浙江大学绍兴研究院生命健康研究中心大健康材料分中心格罗宁根大学Stratingh化学研究所香港中文大学(深圳)理工学院深圳分子聚集体科学与工程研究院

近年来,在非共轭甚至完全不含π电子的结构中发现的反常发光现象引起了人们的广泛关注.然而,由于其发光机制不清以及发光性能较差,导致这一领域的发展较为缓慢.总结了近年来在此类弱作用基发光材料的空间共轭机理研究及性能调控方面的... 详细信息

近年来,在非共轭甚至完全不含π电子的结构中发现的反常发光现象引起了人们的广泛关注.然而,由于其发光机制不清以及发光性能较差,导致这一领域的发展较为缓慢.总结了近年来在此类弱作用基发光材料的空间共轭机理研究及性能调控方面的最新研究进展.首先,基于非共轭多芳基烷烃机理研究模型,提出了弱作用基发光材料的空间共轭机制,并开发了空间共轭的构象和基元电子结构调控策略,基于这些策略成功开发出了高效率全光色发射的弱作用基发光聚合物.与此同时,研究发现空间共轭在传统具有共轭结构的扭转分子中也广泛存在,被认为是聚集诱导发光效应的一个重要发光机理.

关键词：空间共轭弱相互作用荧光多芳基烷烃聚集诱导发光

基于深度学习构建微创肝切除术关键解剖结构识别模型的应用价值

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中华消化外科杂志 2024年第4期23卷 590-595页

作者：陶海粟黎柏宏曾小军郭康炜唐玄霜钱银玲杨剑南方医科大学珠江医院肝胆一科广东省数字医学临床工程技术研究中心广州510280 中国科学院深圳先进技术研究院深圳市虚拟现实与人机交互技术重点实验室深圳518055

目的探讨基于深度学习构建微创肝切除术关键解剖结构识别模型的应用价值.方法采用回顾性描述性研究方法.收集2019年1月至2023年4月在南方医科大学珠江医院保存完整的31个腹腔镜肝左外叶切除术视频资料.由2位肝脏外科医师筛选出包含肝... 详细信息

目的探讨基于深度学习构建微创肝切除术关键解剖结构识别模型的应用价值.方法采用回顾性描述性研究方法.收集2019年1月至2023年4月在南方医科大学珠江医院保存完整的31个腹腔镜肝左外叶切除术视频资料.由2位肝脏外科医师筛选出包含肝左外叶肝蒂、肝左静脉的视频片段,对视频进行质控、筛选、抽帧后,标注图像中的关键解剖结构.所有图像经过预处理后,输送至DeepLab v3+神经网络框架进行模型训练.观察指标:(1)视频标注及分类情况.(2)人工智能解剖识别模型测试结果.正态分布的计量资料以(-x)±s表示,计数资料以绝对数表示.结果 (1)视频标注及分类情况.31个视频共标注4 130帧图像,其中仅有肝左外叶肝蒂的标注图像2083帧,仅有肝左静脉的标注图像1 578帧,同时有肝左外叶肝蒂和肝左静脉的标注图像469帧.(2)人工智能解剖识别模型测试结果.4种场景(干净场景、血渍场景、器械部分遮挡场景、暴露面积小的场景)下,模型成功识别肝左外叶肝蒂或肝左静脉.模型对以上视频图像的解剖识别速度均>13帧/s.模型在对仅有肝左外叶肝蒂的图像进行解剖识别时,Dice系数、交并比、准确度、灵敏度、特异度分别为0.710± 0.110、0.560±0.120、0.980±0.010、0.640±0.030、0.980±0.010;在对仅有肝左静脉的图像进行解剖识别时,上述指标分别为 0.670±0.180、0.530±0.200、0.980±0.010、0.600±0.040、0.990±0.010;在对同时有肝左外叶肝蒂和肝左静脉的图像进行解剖识别时,上述指标分别为0.580±0.180、0.430±0.190、0.980± 0.010、0.580±0.020、0.990±0.010.结论基于深度学习构建微创肝切除术关键解剖结构识别模型可用于识别肝脏肝蒂和静脉结构.

关键词：深度学习微创肝切除术解剖结构计算机视觉图像分割

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构造地质学虚拟仿真实验设计与实现

实验室科学 2024年第4期27卷 51-55,59页

作者：唐亮余养里陈伟王康伟西南石油大学计算机与软件学院四川成都610500 西南石油大学地球科学与技术学院四川成都610500 通威太阳能(成都)有限公司四川成都610500

由于构造地质学研究的对象为各种构造现象,其具有形成过程长期性、变形条件复杂性、变形过程不可逆性及实验室难以完全还原等特征,使得在构造地质学的教学和学习过程中,理论知识和实践观察中的构造现象仅以结果呈现,制约了学生对断层、... 详细信息

由于构造地质学研究的对象为各种构造现象,其具有形成过程长期性、变形条件复杂性、变形过程不可逆性及实验室难以完全还原等特征,使得在构造地质学的教学和学习过程中,理论知识和实践观察中的构造现象仅以结果呈现,制约了学生对断层、褶皱等构造现象形成过程的认识,造成学生无法有效吸收构造地质理论知识并触类旁通应用于构造实践。采用虚拟仿真实验方法是开展该类实验教学和工程实践技能训练的有效途径。以西南石油大学“构造地质学”这门课程的实验教学资源建设为例,介绍其教学资源应用案例、教学体系建设与实现。

关键词：构造地质学虚拟仿真教学体系实验教学