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BIM-based framework of automatic tunnel segment assembly and deviation control

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Underground Space 2024年第3期16卷 59-78页

作者： Jian Gong Tengfei Bao Zheng Zhu Hong Yu Yangtao Li The National Key Laboratory of water Disaster Prevention Hohai UniversityNanjing 210098China College of water conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China College of Hydraulic and Environmental Engineering China Three Gorges UniversityYichang 443002China Zhejiang Design institute of water conservancy and Hydro-Electric power Hangzhou 310002China

The design of universal segments and deviation control of segment assembly are essential for robust and low-risk tunnel construction.A building information modeling(BIM)-based framework was proposed for parametric modeling,automatic assembly,and deviation control of universal ***,segment models of different levels of detail(LoDs)were built based on BIM visual programming language(VPL)for different project life ***,the geometric constraints,requirements,and procedures for parametric segment assembly were distilled to develop a program that combines a novel typesetting algorithm with a 3D path replanning *** is implemented by introducing a point indication matrix,characterizing segments by sides,and manipulating geometries in a ***,3D path replanning,with non-uniform rational B-splines(NURBS)and arcs as basic shapes,was used to resolve unacceptable deviation situations after ***,the proposed framework was validated on a water diversion line and was found to be more effective and accurate than the previous method.

关键词： Parametric generative design BIM Deviation control Typesetting 3D path replanning

Advancement of metal(loid)research on farmland

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Frontiers of Agricultural Science and Engineering 2024年第3期11卷 442-467页

作者： Qiang ZHENG Chenchen WEI Yanbing CHI Peiling YANG College of water Resources and Civil Engineering China Agricultural UniversityBeijing 100083China Agricultural water conservancy Department Changjiang River Scientific Research InstituteWuhan 430019China Zhejiang University of water Resources and Electric power Hangzhou 310018China

Metal(loid)pollution has emerged as a pressing environmental issue in agriculture,garnering extensive public ***(loid)s are potentially toxic substances that infiltrate the soil through diverse pathways,leading to food chain contamination via plant uptake and subsequent animal *** poses a serious threat to environmental quality,food security,and human ***,the remediation of metal(loid)-contaminated agricultural soil is an urgent concern demanding immediate ***,the majority of research papers concentrate on established,isolated remediation technologies,often overlooking comprehensive field management *** is imperative to provide a comprehensive summary of remediation technologies and identify future development *** review aims to comprehensively summarize a range of soil remediation and enhancement technologies,incorporating insights from multiple disciplines including physics,chemistry,biology,and their interdisciplinary *** review examines the mechanisms of action,suitable scenarios,advantages,disadvantages,and benefits associated with each remediation *** relevant is the examination of metal(loid)sources,as well as the mechanisms behind both established and innovative,efficient remediation and enhancement ***,the future evolution of remediation technologies are considered with the aim of offering a scientific research foundation and inspiration to fellow *** is intended to facilitate the advancement of remediation technologies and establish a robust foundation for sustainable development of soil.

关键词： Metal(loid)pollution metal(loid)remediation metal(loid)sources soil

Stability behavior of the Lanxi ancient flood control levee after reinforcement with upside-down hanging wells and grouting curtain

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Journal of Mountain Science 2024年第1期21卷 84-99页

作者： QIN Zipeng TIAN Yan GAO Siyuan ZHOU Jianfen HE Xiaohui HE Weizhong GAO Jingquan School of water conservancy and Environment Engineering Zhejiang University of Water Resources and Electric PowerHangzhou 310018China Department of Civil Engineering Imperial College LondonLondonSW71BFEngland Lanxi water Affairs Bureau Lanxi 321102China Zhejiang water conservancy Engineering Consulting Co. LtdHangzhou 310051China

The stability of the ancient flood control levees is mainly influenced by water level fluctuations, groundwater concentration and rainfalls. This paper takes the Lanxi ancient levee as a research object to study the evolution laws of its seepage, displacement and stability before and after reinforcement with the upside-down hanging wells and grouting curtain through numerical simulation methods combined with experiments and observations. The study results indicate that the filled soil is less affected by water level fluctuations and groundwater concentration after reinforcement. A high groundwater level is detrimental to the levee's long-term stability, and the drainage issues need to be fully considered. The deformation of the reinforced levee is effectively controlled since the fill deformation is mainly borne by the upside-down hanging wells. The safety factors of the levee before reinforcement vary significantly with the water level. The minimum value of the safety factors is 0.886 during the water level decreasing period, indicating a very high risk of the instability. While it reached 1.478 after reinforcement, the stability of the ancient levee is improved by a large margin.

关键词： Stability analysis Multiple factors Antiseepage reinforcement Upside-down hanging well Grouting curtain Ancient levee

Effects of the sand content of muddy water content on one-dimensional vertical infiltration characteristics and dense layer formation characteristics

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 172-179页

作者： Shouxuan Kang Liangjun Fei Yun Zhong Lihua Liu State Key Laboratory of Eco-hydraulics in Northwest Arid Region Xi’an University of TechnologyXi’an 710048China institute of water Resources and Hydro-electric Engineering Xi’an University of TechnologyXi’an 710048China Engineering research Center of Eco-environment in Three Gorges Reservoir Region Ministry of EducationChina Three Gorges UniversityYichang 443002HubeiChina School of water conservancy and hydroelectric power Hebei University of EngineeringHandan 056038HebeiChina

Muddy water irrigation,an effective water-saving irrigation method,has been widely used in the Yellow River Basin in *** investigate the effect of sand content on water infiltration and dense layer formation under one-dimensional vertical infiltration of muddy water,muddy water infiltration experiments were performed in the laboratory,and five sand contents of muddy water(S=0%,3%,6%,9%,and 12%)were *** were established to describe the relationship between the cumulative infiltration amount[I(t)]and the infiltration duration(t);the relationship among the migration distance of the wetting front(Z),S,and t;the thickness of the sedimentary layer[H(t)];and the relationship between S and *** results revealed that I(t)and Z decreased significantly with the increase of sand contents,while H(t)increased significantly with the increase of sand contents.I(t)and Z were in the range of 7 cm and 20 cm for each treatment,*** variation in I(t)with t fitted Kostiakov and Philip models,and the coefficients of determination were all greater than *** the increase in S,the infiltration coefficient gradually decreased,the infiltration index gradually increased,and the sorptivity gradually *** particle composition of the sedimentary layer was similar to that of the argillaceous sediment,and the content of particles with a size of less than 2 mm in the sedimentary layer was lower than that of the argillaceous *** with the original soil,the content of particles with a size of less than 0.05 mm and physical clay particles(diameter less than 0.01 mm)in the soil with an infiltration depth of 0-2 cm *** retention layer was from the topsoil to the infiltration depth of approximately 2 *** study can provide a scientific basis for further research on soil infiltration mechanisms under muddy water.

关键词： muddy water sand content dense layer cumulative infiltration wetting front transport deposit layer thickness

Calculation of Mass Concrete Temperature and Creep Stress under the Influence of Local Air Heat Transfer

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Computer Modeling in Engineering & Sciences 2024年第9期140卷 2977-3000页

作者： Heng Zhang Chao Su Xiaohu Chen Zhizhong Song Weijie Zhan Academy of Science and Technology Changjiang Institute of Survey Planning Design and ResearchWuhan430010China College of water conservancy and Hydropower Engineering Hohai UniversityNanjing210098China Chief Engineer Office Wujiang Company of Goupitan Power Construction CooperationYuqing564408China

Temperature-induced cracking during the construction of mass concrete is a significant *** simulations of concrete temperature have primarily assumed that the concrete is placed in an open *** problem of heat transfer between the air and concrete has been simplified to the concrete’s heat dissipation ***,in the case of tubular concrete structures,where air inlet and outlet are relatively limited,the internal air temperature does not dissipate promptly to the external environment as it *** accurately simulate the temperature and creep stress in tubular concrete structures with enclosed air spaces during construction,we establish an air–concrete coupled heat transfer model according to the principles of conjugate heat transfer,and the accuracy of the model is verified through ***,we conduct a case study to analyze the impact of airflow within the ship lock corridor on concrete temperature and creep *** results demonstrate that enhancing airflow within the corridor can significantly reduce the maximum concrete *** with cases in which airflow within the corridor is neglected,the maximum concrete temperature and maximum tensile stress can be reduced by 12.5℃ and 0.7 MPa,respectively,under a wind speed of 4 m/*** results of the traditional calculation method are relatively close to those obtained at a wind speed of 1 m/***,the temperature reduction process in the traditional method is faster,and the method yields greater tensile stress values for the corridor location.

关键词： Conjugate heat transfer temperature field mass concrete creep stress

Calculation of Mass Concrete Temperature Containing Cooling water Pipe Based on Substructure and Iteration Algorithm

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工程与科学中的计算机建模(英文) 2024年第1期138卷 813-826页

作者： Heng Zhang Chao Su Zhizhong Song Zhenzhong Shen Huiguang Lei Changjiang institute of Survey PlanningDesign and ResearchWuhan430010China College ofwater conservancy and Hydropower Engineering Hohai UniversityNanjing210098China Chief Engineer Office Wujiang Company of Goupitan Power Construction CooperationYuqing564408China

Mathematical physics equations are often utilized to describe physical phenomena in various fields of science and *** such equation is the Fourier equation,which is a commonly used and effective method for evaluating the effectiveness of temperature control measures for mass *** important measure for temperature control in mass concrete is the use of cooling water ***,the mismatch of grids between large-scale concrete models and small-scale cooling pipe models can result in a significant waste of calculation time when using the finite element ***,the temperature of the water in the cooling pipe needs to be iteratively calculated during the thermal transfer *** substructure method can effectively solve this problem,and it has been validated by *** Abaqus/Python secondary development technology provides engineers with enough flexibility to combine the substructure method with an iteration algorithm,which enables the creation of a parametric modeling calculation for cooling water *** paper proposes such a method,which involves iterating the water pipe boundary and establishing the water pipe unit substructure to numerically simulate the concrete temperature field that contains a cooling water *** verify the feasibility and accuracy of the proposed method,two classic numerical examples were *** results showed that this method has good applicability in cooling pipe *** the value of the iteration parameterαis 0.4,the boundary temperature of the cooling water pipes can meet the accuracy requirements after 4∼5 iterations,effectively improving the computational ***,this approach provides a useful tool for engineers to analyze the temperature control measures accurately and efficiently for mass concrete,such as cooling water pipes,using Abaqus/Python secondary development.

关键词： Fourier equation cooling water pipe mass concrete iteration algorithm

Experimental investigation of submerged impinging jets in a plunge pool downstream of large dams

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Science China(Technological Sciences) 1998年第4期41卷 357-365页

作者：刘沛清高季章李永梅 China institute of water conservancy and hydroelectric power research Beijing China

Submerged impinging jets in a plunge pool downstream of large dams are experimentally investigated in details. By use of the hot\|film anemometer, the velocity field in the plunge pool produced by middle orifices of 1∶400 scale Xiluodu spillway model is measured. The diffusive characteristics and energy dissipation mechanism of the submerged impinging jet in the plunge pool are analyzed.

关键词： impinging jet plunge pool energy dissipation.

ISOPARAMETRIC ELEMENT TRANSFORMATION FOR FINITE ANALYTIC METHOD

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Journal of Hydrodynamics 1992年第2期4卷 40-45页

作者： Gao, Zhongxin water conservancy and hydroelectric Power Research Inst Beijing China

Finite analytic method (FAM) is widely used to calculate high Reynolds number flow. However, on complex geometric domain this method must employ boundary-fitted coordinate transformation, which is difficult for some flow regions. In this paper, the isoparametric element was incorporated into the FAM. The flow region was subdivided into a number of small arbitary quadrilaterals and each element was transformed into a square element by the shape functions of isoparametric element. Then, the partial differential equations on the square element can be solved by FAM. Because this transformation is solely local, it is more flexible and convenient than the transformation on the whole domain. To illustrate this transformation, the two-dimensional incompressible viscous flow passing tube bundles has been calculated by this method.

关键词： Finite Element Method Mathematical Techniques Finite Element Method Mathematical Transformations

EFFECTS OF LIQUID QUALITY ON CAVITATION EROSION

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Journal of Hydrodynamics 1992年第2期4卷 87-95页

作者： Zhang, Dong Jin, Tailai water conservancy and hydroelectric Power Research Inst Beijing China

This paper is mainly devoted to conduct a series of vibratory cavitation erosion tests using the magnetostriction apparatus. Distilled water was used as a standard liquid medium for comparison and other liquids were glycerine, kerosene, silicone oil and water containing different concentration glycerine and solid particles, bakerite and fly ash. Experimental results indicate that viscosity of liquid restrains, attenuates and alleviats cavitation erosion. Experiments witness that there exists critical concentration and equivalent concentration. The behaviour of cavitation clouds and the appearance of the pitting were observed. It is helpful to explain the effect of liquid quality on cavitation erosion.

关键词： Cavitation Corrosion Oil Magnetostriction