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Underground Space 2024年第2期15卷 44-58页

作者： Yadong Zhang Ron Chik-Kwong Wong Jianfeng Chen Wei Su department of {1. engineering Schulich School of EngineeringUniversity of CalgaryCalgaryAB T2N 1N4Canada department of Geotechnical {1. College of Civil EngineeringTongji UniversityShanghai 200092China

During pipe installation,compacting soil at pipe sides causes an initial pipe deformation which is known as the"peaking"***,in conventional pipe design codes,only pipe deformation caused by vertical overburden is considered while the"peaking"effect is *** this study,a full-scale test was conducted on a Grade X52 steel pipe with a diameter of 600 mm to investigate the impacts of both soil compaction and vertical overburden on pipe *** compaction and external load were found to elongate and shorten the vertical pipe diameter,***"peaking"effect was observed during the installation procedure accompanied by the highest pipe stress measured at the pipe ***,a two-dimensional finite element model was created and validated based on the calculated pipe stresses from the experimental study.A parametric study was performed thereafter to numerically study the impacts of soil water content,pipe wall thickness,compaction pressure,and lift thickness on pipe responses due to soil compaction and external *** increase in the"peaking"effect is observed with increasing soil water content and compaction pressure,while an increase in pipe wall thickness or lift thickness would cause a decrease in the"peaking"effect.

关键词： X52 steel Soil compaction External load Peaking effect Pipe deflection Soil arching

Hydrodynamic Assessment of A New Nature-Based Armour Unit on Rubble Mound Breakwater for Coastal Protection

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China Ocean engineering 2024年第3期38卷 439-452页

作者： Ehsan SAFA Alireza MOJTAHEDI Abdolmajid MOHAMMADIAN Mohamad Ali Lotfollahi YAGHIN department of Water Resources {1. Faculty of Civil EngineeringUniversity of TabrizTabriz ***Iran Faculty of civil {1. University of OttawaOttawa K1H 8M5Canada

This research proposes a novel nature-based design of a new concrete armour unit for the cover layer of a rubblemoundbreakwater. Armour units are versatile with respect to shape, orientation, surface condition details, and ***, a detailed analysis is required to investigate the exact state of their hydraulic interactions and structuralresponses. In this regard, the performance results of several traditional armour units, including the Antifer cube,Tetrapod, X-block and natural stone, are considered for the first step of this study. Then, the related observed resultsare compared with those obtained for a newly designed (artificial coral) armour unit. The research methodology utilizesthe common wave flume test procedure. Furthermore, several verified numerical models in OpenFOAM code areused to gain the extra required data. The proposed armour is configured to provide an effective shore protection as anenvironmental-friendly coastal structure. Thus it is designed with a main trunk including deep grooves to imitate thetypical geometry of a coral type configuration, so as to attain desirable performance. The observed results and ananalytic hierarchy process (AHP) concept are used to compare the hydraulic performance of the studied traditionaland newly proposed (artificial coral) armour units. The results indicate that the artificial coral armour unit demonstratesacceptable performance. The widely used traditional armour units might be replaced by newer designs for betterwave energy dissipation, and more importantly, for fewer adverse effects on the marine environment.

关键词： rubble mound breakwater hydraulic interaction armour unit analytic hierarchy process numerical model

Evaluation of the seismic behavior of reinforced concrete structures with flat slab-column gravity frame and shear walls through nonlinear analysis methods

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Earthquake engineering and engineering Vibration 2024年第3期23卷 713-726页

作者： M.A.Najafgholipour S.Heidarian Radbakhsh E.Erfani department of {1. and Environmental engineering Shiraz University of TechnologyShiraz ***Iran department of Building Civiland Environmental EngineeringConcordia UniversityMontréal H3G 1M8Canada

This paper presents an investigation of the seismic behavior of reinforced concrete(RC)structures in which shear walls are the main lateral load-resisting elements and the participation of flat slab floor systems is not considered in the seismic design *** this regard,the behavior of six prototype structures(with different heights and plan layouts)is investigated through nonlinear static and time history analyses,implemented in the OpenSees *** results of the analyses are presented in terms of the behavior of the slab-column connections and their mode of failure at different loading ***,the global response of the buildings is discussed in terms of some parameters,such as lateral overstrength due to the gravity flat slab-column *** to the nonlinear static analyses,in structures in which the slab-column connections were designed only for gravity loads,the slab-column connections exhibited a punching mode of failure even in the early stages of ***,the punching failure was eliminated in structures in which a minimum transverse reinforcement recommended in ACI 31.(201.)was provided in the slabs at joint ***,despite neglecting the contribution of gravity flat slab-column frames in the lateral load resistance of the structures,a relatively significant overstrength was imposed on the structures by the gravity frames.

关键词： RC flat slab-column frames seismic behavior nonlinear analysis time history analysis

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 {1. engineering SRM Institute of Science and Technology Tiruchirappalli CampusTrichy 621105India department of {1. engineering National Institute of Technology PatnaBihar 800005India department of {1. engineering Faculty of EngineeringThammasat School of EngineeringThammasat UniversityBangkok10200Thailand department of {1. engineering 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

Development of design charts to predict the dynamic response of pile supported machine foundations

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Frontiers of Structural and civil {1. 2024年第4期18卷 663-679页

作者： Deepthi SUDHI Sanjit BISWAS Bappaditya MANNA department of {1. engineering National Institute TechnologyWarangal 506004India department of {1. engineering Indian Institute of TechnologyDelhi 110016India

This paper proposes design charts for estimating imperative input parameters for continuum approach analysis of the nonlinear dynamic response of *** and analytical studies using continuum approach have been conducted on single and 2×2 grouped piles under coupled and vertical modes of vibration,for different dynamic forces and pile *** these design charts are derived from model piles,the charts have been validated for prototype pile foundations using scaling *** experimental responses of model piles are scaled up and these responses exhibit good agreement with analytical *** study also extends to estimation of the errors in computing frequency–amplitude responses with an increase in pile *** is found that,with an increase in pile length,the errors also *** effectiveness of the proposed design charts is also checked with data based on different field setups given in existing literature,and these charts are found to be ***,the developed design charts can be beneficial in estimating the input parameters for continuum approach analysis for determining the nonlinear responses of pile supported machine foundations.

关键词： pile foundation vertical vibration coupled vibration continuum approach soil-pile separation boundary zone parameters

Parametric investigation on the novel and cost-effective nano fly ash impregnated geopolymer system for sustainable construction

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Frontiers of Structural and civil {1. 2024年第2期18卷 170-183页

作者： R.MOHANA S.M.Leela BHARATHI department of {1. engineering Mepco Schlenk Engineering CollegeSivakasi 626123India

The hazardous environmental effects of greenhouse gas emissions and climate change demand alternative sources for cementitious materials in the construction *** development of geopolymer structures provides a way of producing 1.0%cement-free *** this research work,a novel and simple way of deriving nano particles from waste fly ash particles is *** effect of adding the synthesized nano fly ash particles as a filler medium in geopolymer mortars was investigated by considering strength and durability *** optimization was done by using regression analysis on the geopolymer mortar and the impact of adding nano fly ash particles was studied by varying different percentages of addition ranging from 0 to 7.5%by weight of binder *** the results,it was observed that 1.nano fly ash acted not only as a filler but also as nano-sized precursors of the polymerization process,resulting in denser geopolymer *** can explain the extraordinary gain in strength of 72.1. MPa as well as the denser core with negligible level of chloride ion penetration,making the material suitable for the development of structures susceptible to marine environment.

关键词： geopolymer nano fly ash chloride ion penetration durability polymerization fillers

Mechanical performance of cold mix asphalt containing cup lump rubber as a sustainable bio-modifier

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Journal of Traffic and Transportation engineering(English Edition) 2024年第3期11卷 424-440页

作者： Syed Abdul Ghafar Muhammad Naqiuddin Mohd Warid Norhidayah Abdul Hassan Zulfiqar Ali Jattak Ashraf Abdalla Mohammed Radwan Faculty of civil {1. Universiti Teknologi MalaysiaSkudai 81310Malaysia department of {1. engineering Balochistan University of Information TechnologyEngineering&Management SciencesQuettaPakistan department of {1. engineering Balochistan University of Engineering and TechnologyKhuzdarPakistan department of {1. engineering Faculty of EngineeringUniversity of TripoliTripoliLibya

The road construction industry aims to contribute to the protection of already compromised *** mix asphalt(CMA)is a measure initiated by the road industry to protect the environment and preserve *** having additional benefits,CMA has attracted little attention due to its inferior ***'s performance is enhanced using a sustainable binder bio-modifier,natural cup lump rubber(CLR)is one of *** study evaluated the tensile properties,rutting,moisture susceptibility,and adhesion properties of CLR-modified CMA(CMA-CR).The tensile property was enhanced by 26%due to CLR ***-CR had excellent rutting resistance of less than 2 mm rut depth at 1.,000 load cycles,showing 70%improvement compared with conventional *** susceptibility evaluation indicated that CMA-CR had tensile strength ratio(TSR)value of 1.4%,satisfying the minimum 80%requirement of AASHTO *** also retained more than 96%bitumen *** moisture damage resistance was improved by 1.%and 1.%in terms of TSR and stripping,*** durability results revealed that the CMA-CR mixture prevented higher mass loss,representing 1.%improvement compared with conventional CMA.

关键词： Cup lump rubber Cup lump modified cold mix asphalt Moisture damage Tensile property Rutting Digital imaging

An ultra-thin bolt tension sensor and online monitoring system:For application in hydropower plant unit

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Frontiers of Structural and civil {1. 2024年第9期18卷 1388-1400页

作者： Shaoquan ZHANG Yanke TAN Hanbin GE Qilin ZHANG department of {1. engineering Meijo UniversityNagoya 4688502Japan College of civil {1. Tongji UniversityShanghai 200092China

The condition of bolted connections significantly affects the structural ***,conventional bolt tension sensors fail to provide precise measurements due to their bulky size or inadequate *** study employs the piezoresistive effect of crystalline silicon material to fabricate an ultrathin *** sensor exhibits a linear relationship between pressure and voltage,an exceptional stability at varying temperatures,and a superior resistance to corrosion,making it adaptable and user-friendly for applications of high-strength bolt tension monitoring.A monitoring system,incorporating the proposed sensor,has also been *** system provides real-time display of bolt tension and enables the assessment of sensor and structural conditions,including bolt loosening or component *** efficacy of the proposed sensor and monitoring system was validated through a project carried out at the Xiluodu Hydropower *** to the results,the sensor and online monitoring system effectively gauged and proficiently conveyed and stored bolt tension *** addition,correlations were created between bolt tensions and essential unit parameters,such as water head,active power,and pressures at vital points,facilitating anomaly detection and early warning.

关键词： ultra-thin sensor high-strength bolt tension online monitoring system anomaly alarm hydro-generator units

Probabilistic prediction on three-dimensional roughness of discontinuity based on two-dimensional traces under rock tunnel excavation based on Bayesian theory

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Underground Space 2024年第1期14卷 338-356页

作者： Qi Zhang Yuechao Pei Xiaojun Wang Xiaojun Li Yixin Shen School of civil {1. Southeast UniversityNanjing 211189China department of Geotechnical {1. College of Civil EngineeringTongji UniversityShanghai 200092China

Three-dimensional(3D)roughness of discontinuity affects the quality of the rock mass,but 3D roughness is hard to be measured due to that the discontinuity is invisible in the ***-dimensional(2D)roughness can be calculated from the visible traces,but it is difficult to obtain enough quantity of the traces to directly derive 3D roughness during the tunnel *** this study,a new method using Bayesian theory is proposed to derive 3D roughness from the low quantity of 2D roughness *** more accurately calculating 3D roughness,a new regression formula of 2D roughness is established firstly based on wavelet *** new JRC3D prediction model based on Bayesian theory is then developed,and Markov chain Monte Carlo(MCMC)sampling is adopted to process JRC3D prediction *** discontinuity sample collected from the literature is used to verify the proposed *** groups with the sampling size of 2,3,4,and 5 of each group are randomly sampled from JRC2D values of 1.0 profiles of the discontinuity,*** research results indicate that 1.0%,90%,85%,and 60%predicting JRC3D of the sample groups corresponding to the sampling size of 5,4,3,and 2 fall into the tolerance interval[JRC_(true)–1.JRC_(true)+1..It is validated that the sampling size of 5 is enough for predicting *** sensitivities of sampling results are then analyzed on the influencing factors,which are the correlation function,the prior distribution,and the prior *** discontinuity across the excavation face at ZK78+67.5 of Daxiagu tunnel is taken as the tunnel engineering application,and the results further verify that the predicting JRC3D with the sampling size of 5 is generally in good agreement with JRC3D true values.

关键词： Rock discontinuity Joint roughness coefficient Tunnel excavation Bayesian theory Markov chain Monte Carlo sampling

Seismic response of pile-supported structures considering the coupling of inertial and kinematic interactions in different soil sites

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Frontiers of Structural and civil {1. 2024年第9期18卷 1350-1361页

作者： Huiling ZHAO Fan ZHANG department of {1. engineering Shanghai UniversityShanghai 200444China

Dynamic soil−pile−superstructure interaction is crucial for understanding pile behavior in earthquake-prone *** the safety of piles requires determining the seismic bending moment caused by combined inertial and kinematic interactions,which is *** paper addresses this problem through numerical simulations of piles in different soil sites,considering soil *** reveal that the period of the soil site significantly affects the interaction among soil,piles,and *** moments in soft and hard soil sites exceed those in medium soil sites by more than *** modes of piles exhibit distinct characteristics between hard and soft soil *** soil sites exhibit a singular inflection point,while hard soil sites show two inflection *** soft soil sites,pile-soil kinematic interaction gradually increases bending moment from tip to head,with minor influence from superstructure’s inertial *** hard soil sites,significant inertial effects from soil,even surpassing pile-soil kinematic effects near the tip,lead to reversed superposition bending ***’s inertial interaction notably impacts pile head in hard soil sites.A simplified coupling method is proposed using correlation coefficient to represent inertial and kinematic *** findings provide insights into complex seismic interactions among soil,piles,and structures.

关键词： pile seismic response soft soil inertial interaction kinematic interaction