Culvert Structure Research Articles

Influence of Terrain on Windblown Sand Flow Field Characteristics around Railway Culverts

Aeolian sand hazards are often a threat to culverts, which are important channels and pieces of infrastructure of the desert railway. In addition to wind speed, wind direction, and culvert structure, terrain may also be an important reason for the formation of culvert sand hazards. However, there are few studies on the effect of terrain on the sediment accumulation characteristics of culverts. This paper established computational fluid dynamics (CFD) models of railway culverts (flat and concave culverts) based on Euler’s two-fluid theory. An analysis of the influence of terrain on the distribution law of the flow fields and sand accumulation around railway culverts was carried out. The results show that the horizontal wind speed curves changes in a “W” shape along the centre axis surface from the forecourt to the rearcourt within a range of 30 m~66.8 m. Low-speed backflow is formed at the inlet and outlet of the culvert, and the minimum wind speed reaches −3.6 m/s and −4.2 m/s, respectively, when the height from the bottom of the culvert is 1.0 m and 1.5 m, resulting in intensified sand sedimentation. In concave culverts, the lower the roadbed height, the easier it is for sand to accumulate at the culvert outlet, the rearcourt, and the track; the sand volume fraction is close to 0.63, affecting the normal operation of the trains. On the contrary, the higher the roadbed, the easier it is for sand to accumulate at the culvert inlet, hindering the passage of engineering vehicles and reducing the function of the culverts. These results reveal that terrain plays a pivotal role in the sand accumulation around culverts and that it should be one of the key considerations for the design of new railway culverts. This work can provide a theoretical basis for preventing and managing sand hazards in railway culverts.

MONITORING OF WATER BODIES AND RECLAIMED LANDS AFFECTED BY WARFARE USING SATELLITE DATA

The paper presents the results of monitoring the state of water bodies and reclaimed lands affected by warfare using remote sensing methods and in-situ surveys. On the example of the flooding of the floodplain of the Irpin river by the waters of the Kyiv reservoir as a result of the destruction of the culvert structure, as well as the flooding of the floodplain of the Dnipro river near village Otradokamyanka after the explosion of the Kakhovska hydro power plant (HPP), the change in the area of inundation was calculated based on spectral index maps and surface classification using Sentinel-2 L2A imagery. On the base of Sentinel-2 L2A images, maps of SAVI and NDWI indices were obtained. They revealed the places of soil cover by sediments and the increase of the area of water bodies. Monitoring of reclaimed lands affected by warfare was carried out in the floodplain of the Irpin river on the Irpin Drainage and Moistening System during three time intervals: before the war in 2019; during the fighting in the spring of 2022 and a year after the end of military actions. Studies have shown a significant prevalence of waterlogged areas in the present time, which confirms the destruction of drainage network.The calculated values of the NDVI index turned out to be too high for agricultural crops, which indicates that the lands is overgrown with shrubs. Based on the results of the conducted monitoring, the territory was classified according to the degree of its damage by shell craters. Based on the results of the studies, it is recommended to monitor water bodies and reclaimed lands that have been affected by the war using images of different spatial resolution, a complex of spectral indices, a combination of image bands and in-situ surveys.

Effect of Reinforcement Forms on the Load Bearing Capacity of Prefabricated Box Culvert

Box culvert structure was an essential part of modern infrastructure. Due to the advantages of low pollution and convenient construction, the prefabricated box culvert (PBC) has been gradually utilized in engineering. However, the investigations on load bearing capacity of PBC in different reinforcement forms with same reinforcement ratios were still lack. In the present research, one PBC specimen was tested and discussed by the finite-element analysis (FEA) on load bearing capacity under four-point bending. The load bearing capacity of another three PBCs in different reinforcement forms with the same reinforcement ratios was discussed by the FEA. Results of experimental and numerical investigations showed that: (1) a number of flexural cracks were observed in the midspan bottom of upper slab of PBC, and finally shear failure was observed in bending–shear zone of upper slab of PBC; (2) the number of concrete cracking, plastic deformation of PBC, and stress of rebars reduced by increasing the area of tensile rebars in PBC with reducing the area of compressive rebars under same reinforcement ratios; (3) the ductility and load bearing capacity of PBC increased by increasing the area of tensile rebars with reducing the area of compressive rebars.

Analyses of Box Bridge and Comparison of Structural Behavior using 3D Finite Element and Typical 1D Line Models

Abstract: In civil engineering practice, 1D modeling (also called line modeling) is often the most common method of modeling used for the analyses of structures. It is easy to create the model and saves time without loss of significant accuracy in the results. However, these line models are ideally not a true representation of the behavior of the structure as they are overly simplified versions. Though this simplification leads to quick modeling and reduces analyses-design cycle time, this oversimplification can lead to inaccuracies and over- design that can impact the economy of construction in repeat projects. Also, in the current era of precast modular construction, it would be prudent to analyze a structure as precisely as it can be so that optimal solution is achieved before designing as standard member that can be reused across an array of projects. In this study an effort is made to model a box bridge structure to analyze and compare the behavior of the bridge under railway vehicular train loading. A Road under Bridge (RUB) of 25m barrel length is considered and analysis is carried out by creating two models subjected to IRS vehicular rail axle loading using STAAD.PRO commercial software. A comparison of flexural forces in the culvert structure is made between results of 1D line model versus 3D box finite element model. It was found that flexure at the critical sections of the box based on line model analysis are much higher than those from 3D finite element analysis. In this particular example, a 14% excess of flexural reinforcement and a 40% excess shear reinforcement are required if we design the structure based on line model of analysis. Thus it is inferred that a design based on line model analysis can be overly conservative and uneconomical. It is suggested that detailed 3D finite element analysis be performed for the design of modular and reusable members especially for precast construction and engineering.

Analisis Simple Cell, Twin Cell, dan Tripple Cell Box Culvert Menggunakan Software Ansys

Box culverts are part of a low-rise structure used to convey water in appropriate channels at railroad crossings, flyovers, roads and bridges. The use of box culverts is according to their function, the amount of damage to box culverts is wrong because the functions and loads that can hold the box culverts are also not taken into account. Any force given to the load affects the behavior of the structure contained in the box culvert. IRC is a loading determination that will be given to the box culvert to see the worst structural behavior that occurs. 2D and 3D modeling was carried out using SAP2000 and Ansys Workbench software with the dimensions of the box culvert model measuring 1000 x 1000 x 160 mm and 3 types, namely single box culvert, double box culvert and triple box culvert. The loading on the box culvert is in the form of a divided and evenly distributed load with a loading value in accordance with the provisions of IRC Class A. The box culvert modeling has a quality of 35 MPa and is designed with several types of loading placement on a single box culvert, double box culvert and triple box culvert structure. culvert with an evenly distributed load of 0.205 mm at maximum loading and a maximum moment of 41.988 KN, under maximum loading conditions planned support reinforcement 17D16-250 and 5D16-250 and stirrups D13-250.

Numerical Model for Rectangular Pedestrian Underpass Excavations with Pipe-Roof Preconstruction Method: A Case Study

Under weak geological conditions, soil deformation and surface settlement are the key factors affecting the success of shallow-buried rectangular excavation. To investigate this issue, an underpass of Zhongxiao East Road in Taipei City was used as a case study. The surface settlement and lateral deformation of an underground diaphragm wall caused by the excavation of a rectangular pedestrian underpass using the pipe-roof preconstruction method (PPM) were investigated by 3D finite element analysis. The numerical analysis results showed that the constructed numerical analysis model had considerable accuracy. The use of PPM combined with a box culvert structure to form a pedestrian underpass could effectively control the surface displacement above the box culvert. Under the condition of the same sectional area, the smaller the width of the pipe-roof structure, the more the impact on the ground surface was reduced. The maximum positive bending moment and maximum negative bending moment on the pipe roof produced by excavation at each stage were roughly inversely related to the height per the width of the cross-section of the pipe diaphragm structure. The results showed that the pipe-roof structure was suitable for underground excavation with shallow-buried depth in the soft soil of the Taipei Basin. Moreover, the shallow-buried box culvert was more sensitive to the subsidence caused by construction than the deep-buried box culvert.

Value Engineering For Drainage System Planning On Soekarno Hatta Road Malang City

The development of residential areas is very rapid, both in hilly areas and in "water parking" areas. So that puddles occur in several places, where in the past it did not occur. Floods/puddles during the rainy season that occur in the channel area of Jalan Soekarno - Hatta are caused by the capacity of the existing drainage system being no longer able to accommodate rainwater runoff. The aim of this research is Determining alternative drainage structure designs that are more efficient and effective is carried out on Jalan Soekarno - Hatta Malang City using the Value Engineering method and determining cost and time savings after carrying out Value Engineering in the drainage system planning work on Jalan Soekarno - Hatta Malang City. The results of this study is After doing Value Engineering by following the work plan (Job Plan) alternative 2 has been obtained which is efficient because the cost is cheaper (Rp. 15,881,356.00) than other alternatives, and alternative 2 is more effective because time (23 days) is faster than other alternatives . Whereas the initial cost of the U Gutter pair (existing) work on the Drainage System Planning project to Overcome Floods on Jalan Soekarno - Hatta Malang City is Rp. 17,139,144,126.35. While the cost after being in VE, namely alternative 2 Box Culvert Structure, is Rp. 17,014,195,372.72 so that there is a cost savings of Rp. 124,948,753.62 or 0.46%

Reinforcement on existing concrete that has been reinforced with CFRP

Implementing a box culvert system on bridges is an economical choice due to the reduced material use. This system has a joint that blends between the slab and the abutment walls and pillars. With a stiffer joint, the moment that occurs is smaller than a simple beam system. Box culvert foundations are commonly shallow foundations. Consequently, it is vulnerable to settlement, particularly the abutments that receive soil loads from the bridge embankment. Therefore, making the displacement in the abutments greater than in the pillars.
 The existing box culvert structure at the study site in Semarang, Indonesia has a span of 2 x 15 meters. Reinforcement has been previously carried out using Carbon Fiber Reinforced Polymer (CFRP) to treat cracks. Though, as time passed, the treated cracks reopened and new cracks developed. Structural cracks occur at a negative moment, so that the reinforcement yielded.
 A reinforcement using CFRP does not increase stiffness—thus, a reinforcement with adding external reinforcement system is used. This reinforcement is done by adding 400 x 200 WF profile—connected mechanically by attaching anchors to the slab. Reinforcement with a WF profile is safer due to its mechanical system, which makes it easier to implement and monitor.

Settlement Analysis of Pipe Culvert Situated in Soft Clay Treated with Prefabricated Vertical Drains

Engineering structures built on soft and compressible soils are often subjected to a long‐lasting consolidation settlement. It is difficult to achieve an acceptable level of consolidation during the first few years/days of operation. Similarly, the culvert structure provided at station km 159 + 112 of the Awash‐Kombolcha‐Hara Gebeya Railway Project, Ethiopia, was situated along the route traversing soft clay ground of significant thickness. For the intention of reducing consolidation time and lessening the precarious impact of the postconstruction settlement, the soft clay ground was treated with preloading and prefabricated vertical drains. However, the culvert structure is currently undergoing consolidation settlement with varying magnitudes. The vertical deformation of the culvert site is monitored using settlement gauges installed at the site. Monitoring of the site continued for 120 days to track the extent of ground deformation at the culvert site. However, because of environmental and technical factors like calibration and alignment errors, the settlement instrument readings may be exposed to uncertainties, which may probably affect the safety of the culvert structure. Hence, the study is primarily aimed at evaluating the field deformation performance of the culvert structure for 120 days of the consolidation period through numerical analysis and comparing the result with the site settlement monitoring data. The critical effect of wick drain and some key parameters (fill thickness and wick drain spacing) were also scrutinized. Finite element‐based numerical modeling was conducted by using the 2D GeoStudio/SigmaW package, and the Modified Cam Clay Constitutive model was adopted. The conducted numerical analysis revealed that the finite element result has good agreement with the field settlement monitoring data with only 0.0305 m maximum deviation in which the numerical analysis result remained greater for majority of the consolidation time. It can also be inferred that granular fill thickness and wick drain spacing were the key parameters impacting the settlement of the culvert structure.

Оценка кинематической структуры потока за колодцем заглубленного типа в нижнем бьефе водопропусных сооружений АПК

The purpose of the investigation is to study the operating conditions of the downstream of the low-pressure conjugation and water passageway structures of the reclamation complex of the agro-industrial complex (AIC) in relation to the structural scheme of culvert sections operating in the conditions of the conjugation of the pools by the type of a submerged jet in the presence of a deep, relatively short stilling well. A brief description of the laboratory installation, the measuring equipment used to record turbulent fl ow characteristics and the methodology for performing model studies is given. The results are given on fi nding and studying rational downstream structures and devices (hearth, baffl es, apron) taking into account pulsating fl ow effects on the fastening elements. The fl ow modes behind the culvert structure and spillway dam with a deep well have been established, calculated dependences are given to determine its optimal parameters and assess the average and pulsation components of pressure on the main elements of the downstream devices. On the model operating at the Reynolds numbers over 10000 and Froude numbers in the compressed section from 20 to 120, a design was chosen that provides the greatest energy baffl e effect at the angle of the turbulent jet entry into the well varying within 50°…70°, which includes blocks in addition to the deep short well. This made it possible to analyze the kinematic structure of the fl ow and reveal the intense attenuation of the pulsation component of the fl ow velocities and pressures along the length of the outlet channel by about 20% compared to a jump well of simple outlines, and a decrease in the planned irregularity of the diagrams. All this together confi rmed the effi ciency of the structure on the sloping sections of the reclamation network for the structures with a specifi c fl ow rate in the range of 0.15…5.5 m2 /s. As a result of the research carried out, the design of the device and downstream anchorage has been improved providing the necessary reliability of its operation.

Оценка пропуска минимальных расходов воды сооружениями дюкерного типа мелиоративных систем

Issues related to the design and hydraulic calculation of the transit part of a closed tubular water supply structure of the siphon type is considered. The operating conditions of the siphon with rectangular pipes in the transition mode are evaluated, in which the entrance section of the pipes of the culvert structure experiences increased hydrodynamic loads, often leading to certain destructions. The siphon design was modeled with two breaks along the length with a smooth inlet head and without a head. During the experiments, the absence of infl uence of the inlet head of the tubular HTS on the length of the free-flow section was noted. It has been established that the conditions of formation and features of the hydraulic operation of the siphon in the transient mode are largely determined by its design features. With the flooding of the inlet head, the flow of air into the pipe is hindered and a transition mode of the second type is formed with a slight fluctuation of the water level in the upper pool. The dependence of the location of the point of separation of the flow with a decrease in the passing water flow rate on its value is revealed, which made it possible to obtain a graph of the dependence of the relative length of the non-pressure end section on the square root of the Froude number. A comparison was made with the results of studies by other authors, which showed an increase in the relative length in tubular HTS of the siphon type in sections with reverse slopes at the same Froude numbers. Recommendations are given on the methodology for carrying out hydraulic calculation of tubular structures of the siphon type with minimal flow rates.

Numerical study on mechanical properties of large diameter double-layer shield tunnels under the elevated temperatures in fire

As the development of underground engineering, shield tunnels in single-pipe and double-deck type have been widely used and promoted to improve the utilization rate of the effective space. For this complex structure, fire may trigger tunnel lining structure damage or even the failure of the structure. In this paper, the mechanical properties of a large diameter double-layer shield tunnel under elevated temperatures induced by fire were analyzed numerically. A thermo-mechanical coupling numerical approach was employed to implement the thermo-mechanical models in full size. Aiming at a large-diameter shield tunnel with the internal structure combining road and metro space in Jinan, China, the model is applied in a parametric study to verify the fire resistance of tunnel structures under different configurations and RABT fire exposure. The effects of the internal structure and fire location on the complicated mechanical properties of the tunnel were analyzed. Results from numerical analysis showed that the elevated temperatures have a significant impact on the mechanical properties of tunnel, and the structure subjected to elevated temperatures has obvious expansion deformation and stress change. The internal structure has a great influence on the mechanical properties of the tunnel under elevated temperatures, which is conducive to reducing the radial convergence deformation of the tunnel lining structure and improving the internal force state of the lining structure. The location of the fire in the tunnel has a major influence on the internal force and deformation of the tunnel structure. When the fire occurs in the lower space of the tunnel, the fire safety of the internal box culvert structure should be paid more attention. The key design considerations have been identified as the concrete deck slab and the tunnel lining segmental joints configuration.

Vibration test study on aeolian sand filler of existing slab culvert strengthened by corrugated metal pipe

Inadequate structural bearing capacity has appeared in the Reinforced Concrete (RC) slab culverts in permafrost regions of China which have experienced degradation, and need to meet new codes or standards. Based on the method of strengthening for culvert structure by the corrugated metal pipe (CMP), in this paper, shaking table test and vibration box test were introduced to study the vibrational compactness of aeolian sand filled in the small space between the CMP and existing culvert. The results show that aeolian sand in drying or near saturation can be better compacted; aeolian sand with a higher water content has a lower optimum vibration frequency; the sand within 0.6 m from the vibrator can be effectively compacted and 0.4m is the best; in the vibration frequency range of 50~110 Hz, the modulus of aeolian sand decreases as the frequency increases.

Measured Deformation of Pipe-Roof during Box Culvert Jacking in Soft Ground

RBJ method is suitable for shallow covering and micro-disturbed underpassing project. In this paper, the pipe deformation induced by box culvert jacking is analyzed. The research shows that: (1) The closed pipe-roof frame presented a phenomenon of expanding outward, namely the uplift of top pipe and the settlement of bottom pipe. (2) Along the jacking direction, the deformation of pipes was positioned over the box culvert structure and about 10m in front of the excavation face. (3) Due to the bounded constraint of diagram wall, it’s prone to be a reverse deformation at joint between pipe and diagram wall, and resulting in a wave-type deformation pattern.

Settlement of Geosynthetic Encased Stone Columns Liquefaction Condition in Box Culvert

When the box culvert system is placed on a sandy soil layer with a relatively low bearing capacity and is disposed to potential liquefaction, the soil layer must be repaired to avoid damages to the box culvert structure. The proposed method is Geosynthetic Encased Stone Columns (GESC) to increase the bearing capacity and anticipated the liquefaction potential. however, to meet the criteria for a stable and safe GESC soil improvement in liquefaction conditions, the value of the settlement must meet the requirements for the settlement permit limit. This research was conducted to determine the potential for liquefaction at the study location, to calculate the value of single and group settlements in liquefaction conditions and to analyze the stability of single and group settlements including safe or unsafe in liquefaction conditions. Analysis of liquefaction potential was analyzed based on SPT data using the Valera and Donovan method, and settlement analysis applied the Almeida and Alexiew method. The analysis shows that potential liquefaction due to an earthquake with a magnitude of 9.0 SR will be at a depth of 4 to 8 m. Single and group settlements (144 sets) with an installation distance of 1.2 m with a diameter of 0.4 m and at a depth of 10 m are 246.23 and 214.92 mm, respectively. The entire GESC system is considered to be in an unstable and unsafe condition against potential liquefaction and box culvert loading.

Research on Deformation Characteristics of Tunnel Box Culvert Structure under Different Construction Loads

The box culvert structure is an important part of the internal structure of the tunnel. The stability of the box culvert structure directly affects the safety of the tunnel structure, so it is particularly important for the deformation analysis of the box culvert structure. This study uses the finite element software ABAQUS to establish a numerical model of soil-tunnel-assembled box culvert, and quantitatively analyzes the influence of different construction loads on the deformation of the box culvert structure. Through analysis and summary, the horizontal and vertical deformation of the box culvert structure under construction load and the force deformation performance of the junction of the box culvert structure are obtained. At the same time, the deformation performance of the connection between the internal prefabricated box culvert and the side plate under the load of the construction vehicle is also obtained. It has certain guiding significance for the research on the force of the box culvert structure inside the tunnel.

Project Spotlight: Using precast concrete speeds bridge replacement project through Pennsylvania tunnel

The new State Route 191 bridge replacement project inside Stites Tunnel includes a 345 ft (105 m) long precast concrete box culvert structure inside the tunnel and two new post-tensioned precast con¬crete approach spans. Northeast Prestressed Products in Cressona, Pa., was chosen as the precast concrete producer for the project.

Manual RC Box Culvert Analysis and Designing

The culvert is small structures that are required for the under roads and its uses for the crossing of water like streams under the roads. The culvert structure balances the water flow on both sides of the roads, also is protecting and balance of the embankment to reduce the water flow level. There are different types of culverts shapes, and they are circle, arch, Slap & box; therefore, these can be constructed by using different materials like; stones, bricks, reinforced cement concrete. Since the culvert crossing under the earthen embankment, so the culvert is subjecting a traffic load similarly as the roads carry; therefore, they required to be designed for such loads the acting on the surface of the culvert. This project is dealing with the RCC box culvert with and without cushions. The cushion depends on the road profile at the culvert location.

Linked pools culverts facilities

A mathematical model is presented, a hydraulic jump that appears during the transition of the flow from a turbulent state (Fr>1.0) to critical (Fr<1.0). The main assumptions made to obtain the divergent form of the Saint-Venant hydrodynamic equations are given: - planned (two-dimensional) effects do not affect the flow (but still local energy losses due to sharp turns and changes in the channel shape in the plan can be taken into account; to take into account such losses in local sections of the channel increased local hydraulic resistance is introduced). The results of numerical studies of the downstream of the culvert structure of the medium-pressure reservoir are presented. The developed numerical model using explicit difference schemes is presented. Based on the results of numerical studies of the hydraulic jump, the possibility of establishing the degree of quenching of the excess flow energy having the destructive ability of the construction of the downstream of medium-pressure reservoirs is substantiated. The calculation results showed that an increase in the hydraulic resistance value promotes the displacement of the hydraulic jump against the current and an increase in its associated depths. At the concatenation site of the upstream, there was a sharp decrease in the Froude number from 2.76 to 0.69, with a change in average speed from 8.81 m/s to 3.26 m/s. It is substantiated that from the calculated values of the vertical dimensions of the hydraulic jump with various values of hydraulic resistance and the throughput of the structure, it is possible to determine the horizontal dimensions of the jump, which makes it possible to select the optimal sizes of the downstream attachment zone in and after the hydraulic jump.

Study on the Reinforcement of Existing Slab Culverts by Corrugated Steel in Permafrost Regions

Through the field detection and numerical simulation methods of existing culvert structures, the stress state of the corrugated steel structure strengthened with the slab culvert is studied, the reinforcement effect and stress state of the slab culvert structure in the unfavorable state, the corrosion of the corrugated steel and the change of the fill height are analyzed. Numerical simulation results show: Corrugated steel structure can significantly improve the internal force of the slab culvert structure and the degree of flexural deformation, and the reinforcement effect of the culvert structure under live load is more obvious. Corrugated steel structure can effectively reinforce the existing cover culvert structure when subjected to corrosion and the wall thickness becomes small, and its reinforcement performance decreases slowly with the decrease of wall thickness. When the original cover culvert structure loses its bearing capacity, the corrugated steel structure can still effectively exert the function of the original cover culvert structure. When the top fill height of the slab-culvert is between 1 m and 4 m, the reinforcement effect of the corrugated steel structure is relatively stable.