Study on dynamic response of embedded long span corrugated steel culverts using scaled model shaking table tests and numerical analyses

A series of scaled-model shaking table tests and its simulation analyses using dynamic finite element method were performed to clarify the dynamic behaviors and the seismic stability of embedded corrugated steel culverts due to strong earth-quakes like the 1995 Hyogoken-nanbu earthquake. The dynamic strains of the embedded culvert models and the seismic soil pressure acting on the models due to sinusoidal and random strong motions were investigated. This study verified that the cor-rugated culvert model was subjected to dynamic horizontal forces (lateral seismic soil pressure) from the surrounding ground, which caused the large bending strains on the structure; and that the structures do not exceed the allowable plastic deformation and do not collapse completely during strong earthquake like Hyogoken-nanbu earthquake. The results obtained are useful for design and construction of embedded long span corrugated steel culverts in seismic regions.

The effects of water flow and temperature on thermal regime around a culvert built on permafrost

Temperature and water flow through a culvert beneath the Alaska Highway near Beaver Creek,Yukon,were measured at hourly intervals between June and October 2013.These data were used to simulate the effect of the culvert on the thermal regime of the road embankment and subjacent permafrost.A 2-D thermal model of the embankment and permafrost was developed with TEMP/W and calibrated using field observations.Empirical relations were obtained between water temperatures at the entrance to the culvert,flow into the culvert,and water temperatures inside the structure.Water temperatures at the entrance and inside the culvert had a linear relation,while water temperatures inside the culvert and water flow were associated by a logarithmic relation.A multiple linear regression was used to summarize these relations.From this relationship,changes in the flow rate and water temperatures at the entrance of the culvert were simulated to obtain predicted water temperatures in the culvert.The temperatures in the culvert were used in the thermal model to determine their effects on the ground thermal regime near the culvert.Variation of ±10% in water flow rate had no impact on the thermal regime underneath the culvert.Variation of water temperature at the entrance of the culvert had a noticeable influence on the thermal regime.A final simulation was conducted without insulation beneath the culvert.The thaw depth was 30 cm with insulation,and 120 cm without insulation,illustrating the importance of insulation to the ground thermal regime.

Centrifugal model test and numerical simulation of vertical earth pressure on soft foundation box culvert

To obtain the vertical earth pressure on a soft foundation box culvert and investigate the interaction of the soil-culvert-foundation system, both a centrifugal model test and a numerical simulation were conducted and the comparisons with the current methods to determine the load on a culvert were completed. The results of the model test and numerical analysis are in satisfactory agreement, which shows that the direction of the shear stress between the culvert and the adjacent embankment depends on the differential settlement between them. A vertical earth pressure concentration appears on the culvert with a rigid piles foundation because of a downward shear stress. The ratio of the load on a soft foundation culvert and the overburden pressure above the culvert raises first and then decreases as the backfill height increases. In order to reduce the load on a culvert, it is suggested to limit the stiffness difference of the foundations under the culvert and embankment and to use a light backfill over the culvert.

Frost heave analysis of ballasted track above box culvert and its influence on train vibration

The uneven frost heave of frost-susceptible subgrade soil causes track irregularity,which highly enhances train vibration and affects the comfort and safety of railway transportation.This paper presents a coupled thermo-hydro-mechanical(THM)analysis for the freezing behavior of railway located above a box culvert.The vertical acceleration of the vehicle,an indicator of riding comfort,is predicted through a vehicle dynamic model.The results reveal that the existence of a box culvert changes the subgrade thermal pattern,leading to a deeper frost penetration depth.The frost heave amount above the box culvert is larger than the adjacent section,resulting in uneven track structure upheave and track irregularity.This frostinduced track irregularity highly affects train vibration.

The Collapse of Culverts-Arch in Several Cities around the World, Technical Arguments for Their Maintenance and a Legal Proposal for Prohibiting Their Construction in Mexico

Construction underground pipes and underground culvertsarch (UCA) in order to transport the flow natural rivers and city’s sewage at the same time, is a practice that should be prohibited by the Mexico National Water Law (NWL). When UCA collapse, it causes severe damage to surrounding infrastructure, public and private property, and puts citizens’ lives at risk. This work presents some examples of UCA collapse incidents in several cities around the world, emphasizes how important preventive maintenance of these structures is, highlights the need to classify risk areas, and stresses the need to formulate norms and civil defense plans as article 83 of the NWL suggests. We also propose an addition to Fraction I, article 100 of the National Water Law, to protect the animal and plant life of its banks and safety of their natural runoff.

Relative Depth Effects on Corrugated Culvert Roughness

Fish passage is important to the overall health of an ecosystem. Therefore, it is important to be able to accurately predict flow conditions within a stream crossing for high and low flow periods. This paper evaluates the effect of relative water depth on the hydraulic roughness of culverts at low discharge. A 21 m long, 0.8 m diameter corrugated steel pipe with 0.068 × 0.013 m annular corrugations was used. For relative depths below 0.5, Manning’s n was found to increase with decreasing relative depth. An equation was developed to predict relative depths below 0.5 within a corrugated steel pipe based on the corrugation height, slope and culvert diameter. While Manning’s equation does perform reasonably well, the percent difference from the measured to predicted water levels warrants the use of an additional prediction method at low flows.

Origin of Erosion and Hydraulic Problems of the San Roque Underground Arched Culvert Channel and Its Relationship with the Maximum Flow Rate and the Maximum Permissible Velocity

This work presents the hydrologic estimations of the hydraulic underground arched culvert channel (UACC) in Sabinal Basin, Chiapas, México and the hydrological problems associated with it, such as the erosion phenomenon and abrasion cavity formation in it. On the other hand, the maximum flows that the UACC could transport were analyzed, concluding that it no longer has the hydraulic capacity to transport the flow rate associated to return periods equal to or greater than five years and that maximum permissible velocity UACC’s bottom is 3 m/s.

Seismic Performance Assessment of Reinforced Concrete Box Culverts under Near and Far Fault Seismic Ground Motion Records

Studying the critical response characteristics of reinforced concrete box culverts with diverse geometrical configurations under seismic excitations is a necessary step to develop a reasonable design method. In this work, numerical analysis and assessment of reinforced concrete box culverts for seismic loading in addition to standard static loading from dead and live loads is conducted, aiming to highlight the critical difference in the seismic performances between two and three cell box culverts under near and far-fault ground motion. The results show how and where the seismic loading alters the responses of seismic loading of the models including the effect on safety and failure. The geometrical configurations of the culvert combined with the loading scenarios also significantly influence the magnitude and distribution of the seismic responses. The findings of this work shed light on the critical role of the geometrical configurations and shaking event in the seismic responses of reinforced concrete box culverts and this procedure can be applied as seismic assessment method to any culvert shape, size, and material.

Finite Element Analysis Study of Box Culvert Jacking-Out Construction under Existing Railway Line

To shorten the existing box culvert demolition construction period and ensure the normal operation of the railway, the jacking-out construction method was adopted. The ABAQUS finite element software was used to establish a three-dimensional model of the box culvert and soil body of the relying project, and three excavation thickness (0m, 1 m, 2 m) were used as the main variation parameters for numerical analysis and research, and the change law of the box culvert itself and soil body stress during the culvert jacking out process was obtained. The results show that the jacking force-displacement curves of the three working conditions can be divided into two stages, and the jacking force reaches the maximum value at the moment when the static friction turns into sliding friction at the end of the first stage. The stress distribution at the bottom slab of the box culvert in the jacking process is approximately normal, and the stress decreases with the increase of the roadbed excavation thickness. The increase of the roadbed excavation thickness can reduce the soil pressure on the side of the box culvert and effectively reduce the deformation of the roadbed in the jacking-out process. The deformation of the roadbed during the jacking process can be reduced by increasing the thickness of the roadbed excavation.

Utility Impact below Bridge or Culvert Soffit on Open Channel Flow

The background to this research was a flooding incident that occurred in Bridgend, Co. Donegal, Ireland in August 2017. While several properties were flooded, a flooding case study of a single dwelling house adjacent to the Bridgend River at Riverdale, Bunamayne, Co. Donegal, Ireland is used herein. For this study the flooded site shall be referred to as the “Hegarty property”. A structure in the form of a stone arched culvert is located directly adjacent to the two-storey detached dwelling house on the Hegarty Property. While the culvert is referred to locally as a bridge, within this research the word culvert will be used in connection with the structure. The culvert has a concrete surrounded utility (watermain) crossing at a gradient below the culvert soffit on the upstream face of the structure. The utility obstructed flow through the culvert and contributed to the flooding event. Given the implication of climate change and the increased probability of more extreme flooding events, it was decided to explore the case study to ascertain the factors that contribute to flooding events when utilities are positioned at culvert or bridge structures. This work was completed to assist undergraduate students, researchers, and local authorities in a relatively unknown area of flood causation.

Research on 3D visualization design system of hydraulic culvert

The conventional 2D design method of culverts separated from 3D model cannot directly visualize the process of creating and renewal process. This paper explores graphics application framework of Open GL based on MFC, developing the 3D visualization system of hydraulic culvert. This system effectively integrats with building design, structural design and parametric design and image processing technology. The results can be shown by 3D visualization design.

A CAD Process for Box Culvert Structure Design

CAD process for structure design of box culvert is introduced. It follows the traditional way of culvert design. All working conditions of culvert are taken into account. It can generate load diagram, bending moment diagram and bending moment envelope diagram for a single-hole, double-hole or triple-hole box culvert .That is to say, the whole CAD process for the box culvert structure design is realized with the self-developed system. It has been used to accomplish several projects in China and the results are satisfactory.

Design and Construction Technology of Prefabricated Reinforced Concrete Slab Culverts

Compared with traditional cast-in-situ concrete slab culverts,prefabricated reinforced concrete slab culverts can be produced more quickly and has strong quality controllability,strong earthquake resistance,and repeatability.They will be the primary production method of slab culverts in the future.This article offers a comprehensive review of the design and construction technology associated with prefabricated reinforced concrete slab culverts.The objective is to provide a valuable reference for related enterprises,enhance the quality of design and construction in precast pile configuration,and,in turn,contribute to the advancement of construction projects within our country.

Safety assessment for buried drainage box culvert under influence of underground connected aisle blasting:A case study

Blasting engineering in complex urban environments is considered to influence the safety and stability of the overlying drainage box culvert structure owing to vibration.Therefore,field blasting and vibration tests were performed on the blasting engineering of the Wuhan Metro Line 8 connected aisle,and the LS-DYNA software was used to analyze the dynamic response characteristics of an underground drainage box culvert during the blasting test.The vibration response evolution law of the buried drainage box culvert under blasting vibration was investigated,and a safe surface control standard for the blast vibration of a drainage box culvert is proposed.The results reveal that the maximum tensile stress of the box culvert structure was 0.33 MPa.The peak particle velocity(PPV)and peak tensile stress(PTS)of the drainage box culvert decreased as the water level in the box culvert increased.Based on the relationship between the tensile stress of the box culvert,PPV of the box culvert,and PPV of the surface,it is proposed that the surface control velocity of the buried drainage box culvert is 1.36 cm/s.

Evaluation of seismic behavior of box culvert buried in the ground through centrifuge model tests and numerical analysis

Japan has yet to establish a seismic design for road box culverts(RBCs)because past major earthquakes did not damage them.In recent years,structures with enlarged sectional dimensions(the purpose of which is to optimize the internal space in RBCs)have become common.However,the unknown seismic strength of such large RBCs makes RBC seismic designs increasingly necessary.Several seismic design methods have been developed for and applied to rectangular underground structures,e.g.,cut-and-cover tunnels,which are structurally similar to RBCs.Although these methods are applicable to RBCs,it is uncertain whether they can be applied directly because there are currently no evaluation results from model tests on RBCs,which have unique structural features,e.g.,no haunch at the bottom of the sidewalls.Therefore,we verify a seismic behavior of an RBC and develop a method for evaluating it in order to establish a seismic design for RBCs.We conducted centrifuge model tests subjected to seismic force and a numerical analysis using an elastoplastic finite analysis method,in addition,we validated this analysis by comparing the test and analytical results.The test results show RBCs will most likely develop rocking rotation when the ground strain exceeds approximately 0.08%.A comparison of the numerical and experimental results shows that this analysis can estimate the shear deformation behavior with approximately 90%accuracy in square cross-section cases.Meanwhile,this analysis has tendency to underestimate the axial forces in each case and to overestimate the bending moments of some members in the case of wide cross-sections.

基于BIM技术的桥梁识图课程改革实践研究

随着以BIM技术为核心的建筑信息化改革的全面推行和高职教育1+X证书制度的实施,传统的高职土建、交通运输类专业教育也迎来了新的挑战。本文从高职道桥专业BIM人才培养、专业课程改革实践角度,对课程设计、实施、成效等方面进行了深入探讨,以促进职业教育1+X证书制度背景下课证融通的实现。

Experimental study on concrete box culverts in trenches

Concrete box culverts are widely used in expressways in mountain areas.Many problems frequently take place due to improperly estimated vertical earth pressures on culverts.The prevailing Chinese General Code for Design of Highway Bridges and Culverts(CGCDHBC)stipulates the computation of the design load on culverts primarily based on the linear earth pressure theory,which cannot accurately describe the variation of the vertical load on culverts in trenches.In this paper,a full-scale experiment and numerical simulation were conducted to evaluate the variation of vertical earth pressures on culvert and soil arching in backfill.The variations of foundation pressure and settlement were also analyzed.The result revealed that the soil arch forms when the backfill on the culvert reaches a certain height.The soil arching effect reduces the stress concentration on the crown of the culvert but it is unstable.The vertical earth pressure on top of the culvert is significantly different from that recommended by the CGCDHBC.

Deformation behavior and acting earth pressure of three-hinge precast arch culvert in construction process

The three-hinge precast arch culvert consists of two segmental precast units and three hinge points.It harnesses the passive resistance of an embankment by permitting deflection,resulting in a mechanically stable structure.However,the design of the three-hinge precast arch culvert differs from that of a conventional culvert,prompting the mechanical behavior of the culvert to become an important issue.In this study,therefore,1/5 scale model tests were conducted on a three-hinge precast arch culvert to measure the changes in the inside width and earth pressure acting on the culvert at each step in order to investigate the culvert’s mechanical behavior at each construction stage.Moreover,the deflection measurement of the culvert was obtained at the in-situ construction site.The results indicate that the arch members were displaced according to the embankment depth in a similar manner to the design load.Therefore,the horizontal earth pressure,which was larger than the earth pressure at rest,acted on the culvert at the end of its construction.

河道防洪治理的工程措施探析

针对诸多河道治理工程措施尚无系统比较分析,易造成经费浪费或治理效果不达标的情况发生,本文简要介绍了河道防洪治理各工程措施的特点,并以徒骇河防洪治理工程为例,详细介绍了一种“防洪墙护岸+河道清理+排水涵闸”的综合治理措施,其思路和经验可供类似工程治理项目参考借鉴。