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Gravel hardness effect on compaction characteristics of gravelly soil

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Journal of Mountain Science 2024年第4期21卷 1432-1443页

作者： SHI Yunfang LI Shengang JIANG Chen LIU Jinning school of Resources and {1. engineering Northeastern UniversityShenyang 110004China

The compaction characteristics of gravelly soil are affected by gravel *** investigate the evolution and influencing mechanism of different gravel hardness on the compaction characteristics of gravelly soil,heavy compaction tests and crushing tests were conducted on gravelly soils with gravels originated from hard,soft and extremely soft *** to orthogonal experiments and variance analysis,it was found that hardness has a significant impact on the maximum dry density of gravelly soil,followed by gravel content,and lastly,moisture *** gravel compositions with an average saturated uniaxial compressive strength less than 60 MPa,the order of compacted maximum dry density is soft gravels>hard gravels>extremely soft *** type of gravelly soil has a threshold for gravel content,with 60%for hard and soft gravels and 50%for extremely soft *** these thresholds,the compacted dry density decreases *** is a certain interaction between hardness,gravel content,and moisture *** hardness increases the influence of gravel content,whereas lower hardness increases the influence of moisture *** soils with the coarse aggregate(CA)between 0.7 and 0.8 typically achieve higher dry densities after *** addition,the prediction equations for the particle breakage rate and CA ratio in the Bailey method were proposed to estimate the compaction performance of gravelly soil *** results further revealed the compaction mechanism of different gravelly soils and can provide reference for subgrade filling construction.

关键词： Gravelly soil Hardness Compaction characteristics Crushing characteristics Particle breakage rate Bailey method

A cumulative damage model for predicting and assessing raveling in asphalt pavement using an energy dissipation approach

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Frontiers of Structural and civil {1. 2024年第6期18卷 949-962页

作者： Kailing DENG Duanyi WANG Cheng TANG Jianwen SITU Luobin CHEN school of {1. engineering and Transportation South China University of TechnologyGuangzhou 510640China

Raveling is a common distress of asphalt pavements,defined as the removal of stones from the pavement *** predict and assess raveling quantitatively,a cumulative damage model based on an energy dissipation approach has been developed at the meso *** construct the model,a new test method,the pendulum impact test,was employed to determine the fracture energy of the stone-mastic-stone meso-unit,while digital image analysis and dynamic shear rheometer test were used to acquire the strain rate of specimens and the rheology property of mastic,*** of the model reveals that when the material properties remain constant,the cumulative damage is directly correlated with loading time,loading amplitude,and loading ***,damage increases with superimposed linear and cosine variations over time.A higher stress amplitude results in a more rapidly increasing rate of damage,while a lower load frequency leads to more severe damage within the same loading ***,an example of the application of the model has been presented,showing that the model can be utilized to estimate failure life due to *** model is able to offer a theoretical foundation for the design and maintenance of anti-raveling asphalt pavements.

关键词： asphalt pavement raveling cumulative damage dissipation energy theory

Sensitivity of optimal double-layer grid designs to geometrical imperfections and geometric nonlinearity conditions in the analysis phase

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Frontiers of Structural and civil {1. 2024年第8期18卷 1209-1224页

作者： Amirali REZAEIZADEH Mahsa ZANDI Majid ILCHI GHAZAAN school of {1. engineering Iran University of Science and TechnologyTehran 16846-13114Iran

This study focuses on exploring the effects of geometrical imperfections and different analysis methods on the optimum design of Double-Layer Grids(DLGs),as used in the construction industry.A total of 1. notable metaheuristics are assessed and contrasted,and as a result,the Slime Mold Algorithm is identified as the most effective approach for size optimization of *** evaluate the influence of geometric imperfections and nonlinearity on the optimal design of real-size DLGs,the optimization process is carried out by considering and disregarding geometric nonlinearity while incorporating three distinct forms of geometrical imperfections,namely local imperfections,global imperfections,and combinations of *** light of the uncertain nature of geometrical imperfections,probabilistic distributions are used to define these imperfections randomly in direction and *** results demonstrate that it is necessary to account for these imperfections to obtain an optimal ***’s worth noting that structural imperfections can increase the maximum stress ratio by up to 70%.The analysis also reveals that the initial curvature of members has a more significant impact on the optimal design of structures than the nodal installation error,indicating the need for greater attention to local imperfection issues in space structure construction.

关键词： double-layer grid sizing optimization metaheuristic algorithms geometrical imperfections analysis approach

Graph Convolutional Networks Embedding Textual Structure Information for Relation Extraction

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Computers, Materials & Continua 2024年第5期79卷 3299-3314页

作者： Chuyuan Wei Jinzhe Li Zhiyuan Wang Shanshan Wan Maozu Guo school of Electrical and Information {1. Beijing University of Civil Engineering and ArchitectureBeijing102616China

Deep neural network-based relational extraction research has made significant progress in recent years,andit provides data support for many natural language processing downstream tasks such as building knowledgegraph,sentiment analysis and question-answering ***,previous studies ignored much unusedstructural information in sentences that could enhance the performance of the relation extraction ***,most existing dependency-based models utilize self-attention to distinguish the importance of context,whichhardly deals withmultiple-structure *** efficiently leverage multiple structure information,this paperproposes a dynamic structure attention mechanism model based on textual structure information,which deeplyintegrates word embedding,named entity recognition labels,part of speech,dependency tree and dependency typeinto a graph convolutional ***,our model extracts text features of different structures from theinput *** Structure information Graph Convolutional Networks employs the dynamic structureattention mechanism to learn multi-structure attention,effectively distinguishing important contextual features invarious structural *** addition,multi-structure weights are carefully designed as amergingmechanismin the different structure attention to dynamically adjust the final *** paper combines these featuresand trains a graph convolutional network for relation *** experiment on supervised relation extractiondatasets including SemEval 201. Task 8,TACRED,TACREV,and Re-TACED,the result significantly outperformsthe previous.

关键词： Relation extraction graph convolutional neural networks dependency tree dynamic structure attention

Prediction of bearing capacity of pile foundation using deep learning approaches

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Frontiers of Structural and civil {1. 2024年第6期18卷 870-886页

作者： Manish KUMAR Divesh Ranjan KUMAR Jitendra KHATTI Pijush SAMUI Kamaldeep Singh GROVER Department of civil {1. SRM Institute of Science and Technology Tiruchirappalli CampusTrichy 621105India Department of civil {1. National Institute of Technology PatnaBihar 800005India Department of civil {1. Faculty of EngineeringThammasat School of EngineeringThammasat UniversityBangkok10200Thailand Department of civil {1. Rajasthan Technical UniversityKota 324010India

The accurate prediction of bearing capacity is crucial in ensuring the structural integrity and safety of pile *** research compares the Deep Neural Networks(DNN),Convolutional Neural Networks(CNN),Recurrent Neural Networks(RNN),Long Short-Term Memory(LSTM),and Bidirectional LSTM(BiLSTM)algorithms utilizing a data set of 257 dynamic pile load tests for the first ***,this research illustrates the multicollinearity effect on DNN,CNN,RNN,LSTM,and BiLSTM models’performance and accuracy for the first time.A comprehensive comparative analysis is conducted,employing various statistical performance parameters,rank analysis,and error matrix to evaluate the performance of these *** performance is further validated using external validation,and visual interpretation is provided using the regression error characteristics(REC)curve and Taylor *** from the comparative analysis reveal that the DNN(Coefficient of determination(R^(2))_(training(TR))=0.97,root mean squared error(RMSE)_(TR)=0.041.;R^(2)_(testing(TS))=0.9,RMSE_(TS)=0.08)followed by BiLSTM(R^(2)_(TR)=0.91.RMSE_(TR)=0.782;R^(2)_(TS)=0.89,RMSE_(TS)=0.0862)model demonstrates the highest performance *** is noted that the BiLSTM model is better than LSTM because the BiLSTM model,which increases the amount of information for the network,is a sequence processing model made up of two LSTMs,one of which takes the input in a forward manner,and the other in a backward *** prediction of pile-bearing capacity is strongly influenced by ram weight(having a considerable multicollinearity level),and the effect of the considerable multicollinearity level has been determined for the model based on the recurrent neural network *** this study,the recurrent neural network model has the least performance and accuracy in predicting the pile-bearing capacity.

关键词： deep learning algorithms high-strain dynamic pile test bearing capacity of the pile

Performance of Bacillus tropicus on Mechanical,Durable and Crack Remediation Properties in Sustainable Vermiculite Concrete

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Journal of Bionic engineering 2024年第4期21卷 1987-1999页

作者： Anbazhagan Rajesh Venkatesh Sri Hariny Arunachalam Sumathi school of {1. engineering SASTRA Deemed to be UniversityThirumalaisamudramThanjavurTamilnadu613401India

Sustainable cement-based concrete materials are primarily used for construction,among which vermiculite as lightweight fine aggregate gains more future development ***,a bacterial solution was sprayed over vermiculite and wrapped using calcium sulphoaluminate(CSA)cement to replace with fine aggregate in ***,based on a preliminary test on compressive strength results,1.%of Ground Granulated Blast Furnace Slag(GGBS)and a healing solution proportion of 9:1.was selected for preparing self-healing *** fine aggregate was replaced in concrete using vermiculite in 0%,5%,1.%and 1.%and the findings suggest that bacterial vermiculite replacement should be at most 5%to achieve better results in strength and durable *** strength enhancement observed for compressive strength,strength regain,split tensile strength,flexural strength,and ultrasonic pulse velocity were 29.22%,45.5%,34.02%,28.03%and 41.4%*** crack healing at 7,1. and 28 days of BIVC was 38.23%,58.82%and 79.41.,which is 3–4%lower than internal crack *** analysis by Scanning Electron Microscopy(SEM),X-Ray Diffractometer(XRD),and Energy Dispersive Spectroscopy(EDS)reveals the existence of calcite,and it was formed due to the bio-mineral action of bacteria with available nutrients in sustainable concrete.

关键词： Bacillus tropicus Vermiculite Ground granulated blast furnace slag Mechanical properties Durable properties Crack healing Microstructural characterization

Extending the decision-making process during yellow phase from human drivers to autonomous vehicles:A microsimulation study with safety considerations

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Journal of Traffic and Transportation engineering(English Edition) 2024年第2期11卷 362-379页

作者： Efthymis Papadopoulos Anastasia Nikolaidou Emmanouil Lilis Ioannis Politis Panagiotis Papaioannou Transport engineering Laboratory School of Civil EngineeringFaculty of EngineeringAristotle University of ThessalonikiThessaloniki 54124Greece

One of the main factors affecting the safety of signalised intersections is the stop/go behaviour during the yellow *** previous research has exhaustively examined drivers’stop/go decision-making,the expected autonomous vehicles’(AVs’)stop/go behaviour has not yet been thoroughly *** a series of simulation experiments developed for conventional and autonomous vehicles using different carfollowing,lane-changing,lateral placement and stop/go model parameter values,we examine here whether the default VISSIM stop/go parameter values can adequately replicate the observed drivers’behaviour at the considered intersection and assess the suitability of using the currently available options,albeit referring to human drivers,to simulate the expected stop/go behaviour of *** also propose a policy framework for determining the desired behaviour of AVs in yellow interval,which is integrated into an AVs logic and achieved in the last simulation to explore the effect of automation on the stop/go outcome and,hence,on the safety level of signalised *** data analysis and modeling techniques were used for the formulation of certain scenarios,including binary choice *** default stop/go parameter values were found unfit to replicate the observed stop/go behaviour and subjected to *** to the currently available options,the proposed AVs logic proved to produce the most accurate results,in terms of the stop/go simulation *** the impact of automation on the stop/go outcome,the simulation experiments showed that AVs preferred a more conservative behaviour in favor of road safety,as indicated by the significant reduction(≈1.%)in the number of vehicles crossing the stop line during the yellow light and zero instances of red light ***,compared to the conservative drivers represented by the default stop/go parameter values,AVs preferred a more rational behaviour in favor of intersection capacit

关键词： Driver behaviour AVs behaviour Signalised intersection Choice model Micro-simulation Policy framework

Determination of ice jam thickness—A new approach

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Journal of Hydrodynamics 2024年第3期36卷 570-581页

作者： Jun Wang Lian-sheng Sang Fei-hu Song Tie-jie Cheng Jueyi Sui school of {1. and Water engineering Hefei University of TechnologyHefei230009China school of {1. University of Northern British ColumbiaPrince GeorgeCanada

In winter,rivers in cold regions often experience flood disasters resulted from ice jams or ice *** of the variation of ice jam thickness and water level during an ice jammed period are not only a practical need for ice prevention to avoid disaster and plan water resource,but also essential for the development of any mathematical model for predicting the evolution of ice *** far,some equations based on the energy equation have been proposed to describe the relationship between ice jam thickness and water ***,in the derivation of these equations,the local head loss coefficient at the ice jam head and the riverbed slope factor were ***,those reported equations cannot be used to preciously describe the flow energy equation with ice jams and accurately calculate the ice jam thickness and water *** the present study,a more comprehensive theoretical model for hydraulic calculation of ice jam thickness has been derived by considering important and essential factors including riverbed slope and local head loss coefficient at the ice jam ***,based on the data collected from laboratory experiments of ice jam accumulation,the local head loss coefficient at the ice jam head has been calculated,and the empirical equation for calculating the local head loss coefficient has been established by considering flow Froude number and the ratio of ice discharge to flow *** results of this study not only provide a new reference for calculating ice jam thickness and water level,but also present a theoretical basis for accurate CFD simulation of ice jams.

关键词： Energy equation ice jam thickness local head loss coefficient ice jam head riverbed slope

Quasi-static and dynamic compressive behaviour of additively manufactured Menger fractal cube structures

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Defence Technology（防务技术） 2024年第7期37卷 39-49页

作者： Damith Mohotti Dakshitha Weerasinghe Madhusha Bogahawaththa Hongxu Wang Kasun Wijesooriya Paul JHazell school of {1. and Technology UNSWCanberraACT2600Australia school of {1. Mining and Environmental EngineeringFaculty of Engineering and Information SciencesUniversity of WollongongWollongongNSWAustralia

This paper presents the first-ever investigation of Menger fractal cubes'quasi-static compression and impact *** cubes with different void ratios were 3D printed using polylactic acid(PLA)with dimensions of 40 mm×40 mm×40 *** different orders of Menger cubes with different void ratios were considered,namely M1.with a void ratio of 0.26,M2 with a void ratio of 0.45,and M3with a void ratio of ***-static Compression tests were conducted using a universal testing machine,while the drop hammer was used to observe the behaviour under impact *** fracture mechanism,energy efficiency and force-time histories were *** the structured nature of the void formation and predictability of the failure modes,the Menger geometry showed some promise compared to other alternatives,such as foams and *** the increasing void ratio,the Menger geometries show force-displacement behaviour similar to hyper-elastic materials such as rubber and *** third-order Menger cubes showed the highest energy absorption efficiency compared to the other two geometries in this *** findings of the present work reveal the possibility of using additively manufactured Menger geometries as an energy-efficient system capable of reducing the transmitting force in applications such as crash barriers.

关键词： Additive manufacturing Fractal geometries Menger cube Energy absorption Quasi-static