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Selection of digital fabrication technique in the construction industry--A multi-criteria decision-making approach

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Frontiers of Structural and Civil engineering 2024年第7期18卷 977-997页

作者： M.P.SALAIMANIMAGUDAM J.JAYAPRAKASH department of Structural and {1. engineering School of Civil EngineeringVellore Institute of TechnologyVellore 632014India

Digital fabrication techniques,in recent decades,have provided the basis of a sustainable revolution in the construction ***,selecting the digital fabrication method in terms of manufacturability and functionality requirements is a complex *** paper presents alternatives and criteria for selection of digital fabrication techniques by adopting the multi-criteria decision-making *** alternatives considered in the study are concrete three-dimensional(3D)printing,shotcrete,smart dynamic casting,material intrusion,mesh molding,injection concrete 3D printing,and thin forming *** criteria include formwork utilization,reinforcement incorporation,geometrical complexity,material enhancement,assembly complexity,surface finish,and build *** demonstrates different multi-criteria decision-making techniques,with both subjective and objective weighting *** given ranking is based on the current condition of digital fabrication in the construction *** study reveals that in the selection of digital fabrication techniques,the criteria including reinforcement incorporation,build area,and geometrical complexity play a pivotal role,collectively accounting for nearly 70% of the overall *** the evaluated techniques,concrete 3D printing emerged as the best performer,however the shotcrete and mesh molding techniques in the second and third positions.

关键词： digital fabrication multicriteria decision-making concrete 3D printing

Centrifuge study on behavior of raft foundation after tunnelling in soft clay

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Underground Space 2024年第4期17卷 161-169页

作者： Jian Yu Jiaming Liu Chun Fai Leung Maosong Huang Qi Wen Jorgin Tan department of {1. engineering Key Laboratory of Geotechnical and Underground Engineering of Ministry of EducationTongji UniversityShanghai 200092China Centre for Offshore Research and engineering Department of Civil and Environmental EngineeringNational University of Singapore119077Singapore Land Transport Authority 219428Singapore

Ground losses due to tunneling would induce settlement of nearby raft *** study the change in behavior of the raft foundations over time due to tunnel excavation in soft clay,a series of centrifuge model tests were *** results reveal that the raft stiffness has a significant influence on the development of the gap between the raft and the *** width of the gap beneath the flexible foundation would increase over time,leading to a further increase in tensile strain after excavation,whereas the gap for raft foundations with a large stiffness would reduce with time,causing a gradual decrease in tensile *** modification factor(MF)design approach is also evaluated with the test results and demonstrates that the MF design approach would underestimate the tensile strain of the flexible raft and provide a relatively conservative prediction for larger stiffnesses.

关键词： Tunnelling Raft Clay Deflection ratio Centrifuge test

Effect of pipe installation and external load on buried steel pipe responses:Experimental and numerical investigations

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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 Civil {1. Schulich School of EngineeringUniversity of CalgaryCalgaryAB T2N 1N4Canada department of {1. engineering 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

A modified smoothed particle hydrodynamics method considering residual stress for simulating failure and its application in layered rock mass

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Journal of Mountain Science 2024年第6期21卷 2091-2112页

作者： XIA Chengzhi SHI Zhenming KOU Huanjia department of {1. engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of geotechnical and Underground {1. of Ministry of Education Tongji UniversityShanghai 200092China

Residual strength is an indispensable factor in evaluating rock fracture,yet the current Smoothed Particle Hydrodynamics(SPH)framework rarely considers its influence when simulating *** improved cracking strategy considering residual stress in the base bond SPH method was proposed to simulate failures in layered rocks and slopes and verified by experimental results and other simulation methods(i.e.,the discrete element method).Modified Mohr–Coulomb failure criterion was applied to distinguish the mixed failure of tensile and *** fracture markψwas introduced to improve the kernel function after tensile damage,and the calculation of residual stress after the damage was derived after shear *** simulations were carried out to evaluate its performance under different stress and scale conditions and to verify its effectiveness in realistically reproducing crack initiation and propagation and coalescence,even fracture and *** results indicate that the improved cracking strategy precisely captures the fracture and failure pattern in layered rocks and rock *** residual stress of brittle tock is correctly captured by the improved SPH *** improved SPH method that considers residual strength shows an approximately 1.%improvement in accuracy for the safety factor of anti-dip layered slopes compared to the method that does not consider residual strength,as validated against analytical *** infer that the improved SPH method is effective and shows promise for applications to continuous and discontinuous rock masses.

关键词： Smoothed particle hydrodynamics Cracking strategy Residual stress Layered rock Crack propagation

Model-based offline reinforcement learning framework for optimizing tunnel boring machine operation

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Underground Space 2024年第6期19卷 47-71页

作者： Yupeng Cao Wei Luo Yadong Xue Weiren Lin Feng Zhang department of Urban Management Kyoto UniversityKyoto 615-8540Japan department of {1. engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of geotechnical and Underground {1. of Ministry of Education Tongji UniversityShanghai 200092China

Research on automation and intelligent operation of tunnel boring machine(TBM)is receiving more and more attention,benefiting from the increasing construction ***,most studies on TBM operations optimization were trained by the labels of human drivers’decisions,which were subjective and *** a result,the control parameters suggested by these models could hardly surpass the performance of a human driver,even the possibility of subjective incorrect *** that the geomechanical feedback to TBM under drivers’actions is objective,in this paper,a transformer-based model called the geological response for tunnel boring machine(GRTBM),is proposed to learn the relationship between operation-adjust and TBM monitoring ***,with the model-based offline reinforcement learning,this paper provided a novel approach to optimizing the TBM excavation *** decision processes,recorded in the Yin-song TBM project for a waterway tunnel in Jilin Province of China,were used for the validation of the *** adopting an implicit perception of geological conditions in the GRTBM model,the suggested method achieved the desired state within a single action,greatly outperformed the practical adjustments where 500 s were taken,revealing the fact that the proposed model has the potential to surpass the capability of human beings.

关键词： TBM Reinforcement learning Transformer Data mining

Self-initiated static-dynamic state transition behavior and triggering mechanism of strain rockburst using three-dimensional discrete element method

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Underground Space 2024年第3期16卷 143-163页

作者： Yuan Qian Cheng Zhao Rui Wei Rui Zhang Lin Huang Huiguan Chen department of {1. engineering College of Civil EngineeringTongji UniversityShanghai 200092China Key Laboratory of geotechnical and Underground {1. of Ministry of Education Tongji UniversityShanghai 200092China School of engineering Tibet UniversityLhasaTibet850000China

The accurate understanding of rockburst mechanism poses a global challenge in the field of rock *** for strain rockburst,achieving self-initiated static-dynamic state transition is a crucial step in the formation of catastrophic ***,the state transition behavior and its impact on rockburst have not received sufficient attention,and are still poorly ***,this study specifically focuses on the state transition behavior,aiming to investigate its abrupt transition process and formation mechanism,and triggering effects on *** facilitate the study,a novel burst rock-surrounding rock combined laboratory test model is proposed and its effectiveness is validated through experiment ***,corresponding numerical models are established using the three-dimensional(3D)discrete element method(DEM),enabling successful simulation of static brittle failure and rockbursts of varying intensities under quasi-static displacement loading ***,through secondary development,comprehensive recording of the mechanical and energy information pertaining to the combined specimen system and its subsystems is *** a result of numerical investigation studies,the elastic rebound dynamic behavior of the surrounding rock was discovered and identified as the key factor triggering rockburst and controlling its *** impact loading on the burst rock,induced by elastic rebound,directly initiates the dynamic processes of rockburst,serving as the direct ***,the transient work and energy convergence towards the burst rock resulting from elastic rebound are recognized as the inherent cause of ***,it has been observed that a larger extent of surrounding rock leads to a stronger elastic rebound,thereby directly contributing to a more intense *** findings can provide novel theoretical insights for the exploring of rockburst mechanism and the development of monitoring and

关键词： Strain rockburst Static-dynamic state transition Self-initiation Triggering mechanism Elastic rebound Discrete element method

Planning an adaptive reuse development of underutilized urban underground infrastructures:A case study of Qingdao,China

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Underground Space 2024年第1期14卷 18-33页

作者： Yong-Kang Qiao Fang-Le Peng Yun-Hao Dong Chun-Fang Lu Research Center for Underground Space&department of {1. engineering Tongji UniversityShanghai 200092China

Urban underground infrastructures(UUIs)are a vital component of built capital for urban ***,many cities are now home to a multitude of disused or underutilized UUIs,not least aged purpose-built underground facilities,causing a waste of valuable underground space resource *** the process of urban renewal,adaptive reuse can be an attractive solution to breathe new life into underutilized UUIs,while addressing some of the modern problems of the built environment by an economically feasible ***,there is a prevalent absence in the current literature of the overarching planning and decision-making approaches for an adaptive reuse development of underutilized *** the intention of addressing this shortfall,this paper first lays out development strategies,then sets the generic patterns for adaptive reuse of disused or underutilized *** the city of Qingdao,China as a case study,detailed planning and decision-making approaches with the aid of multi-source data and spatial analysis tools are *** is anticipated that the findings of this research will assist the adaptive reuse development of UUIs in providing theoretical guidance and empirical evidence,thereby enhancing the role of urban underground space use in contributing to urban revitalization and urban sustainability.

关键词： Urban underground infrastructures Underutilized Adaptive reuse Planning Urban renewal

Quantitative evaluation of the contribution of underground space to urban resilience:A case study in China

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Underground Space 2024年第4期17卷 1-24页

作者： Si-Cong Liu Fang-Le Peng Yong-Kang Qiao Yun-Hao Dong Research Center for Underground Space&department of {1. engineering Tongji UniversityShanghai 200092China

Urban underground space(UUS)development has been acknowledged as a positive contribution to urban resilience(UR).Such contribution has been qualitatively addressed in recent years,but only quantitatively discussed in few *** evaluation methods for UR are widely used in China and around the world,but the role of underground space is barely *** paper provides a way to bridge this gap on the city scale.A UR evaluation framework was carefully constructed that covers the basic aspects and elements of *** contributions of UUS to UR were identified and integrated into the UR evaluation framework,and the measurement methods for each indicator related to UUS were determined.A case study of 1. sample cities in China were conducted using the integrated evaluation *** analysis and clustering analysis were further adopted to interpret the evaluation results,mainly with three indicators reflecting the level of UUS development,namely UUS area(m^(2)),UUS density(1.4 m^(2)/km^(2))and UUS area per capita(m^(2)/person).The results showed a strong correlation between UUS area and *** average proportion of UR provided by UUS in the 1. sample cities was 1..46%,while the maximum figure reached 29.20%.The sample cities were clustered into four categories based on the relationship between the proportion of UR provided by UUS,UUS area,and GDP per capita,where both high and low UUS area tend to provide less proportion of resilience than the medium UUS *** suggestions for UUS utilization were proposed to assist cities in achieving urban resilience.

关键词： Urban underground space(UUS) Urban resilience Resilience evaluation Resilient development

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Book Review

Underground Space 2024年第6期 4-5页

作者： Dongming Zhang Key Laboratory of geotechnical and Underground {1. of Ministry of Education Tongji UniversityShanghai 200092China department of {1. engineering College of Civil EngineeringTongji UniversityShanghai 200092China

Uncertainty,Modeling,and Decision Making in Geotechnics Edited by Kok-Kwang Phoon,Takayuki Shuku,and Jianye Ching,CRC Press,ISBN:978-1.032-36750-7,https://***/1..1.01.9781.03333586 The pervasive challenge of inherent uncertainty stands as one of the most widely acknowledged hurdles in geotechnical and rock *** of failures in geotechnics are frequently reported worldwide,often stemming from unpredictable ground properties during design,inadequate quality control measures,or erroneous decision-making processes.

关键词： engineering. measures rock