Concrete Abutments Research Articles

Seasonal Variations Of Attached Cyanophyceae Algae on Cocreate Brideges In Tigress Rivere From Baghdad

The attached Cyanophyta community is a model for monitoring aquatic systems and interpreting environmental change in aquatic systems. The present study aims to conduct a seasonal study on Cyanophyta attached to the concrete abutments of three bridges (Al-Jadriya Bridge, Bab Al-Moadam Bridge, and Al-Muthanna Bridge) in the Tigris River within the city of Baghdad, central Iraq (from October 2021 to June 2022). The study included the quality of Cyanophyta and, the eleven environmental parameters (water temperature, electric conductivity, salinity, pH, total alkalinity, Calcium, Magnesium, dissolved oxygen, total dissolved solids, total phosphorus, and total nitrogen). Monthly samples were taken from the water under each bridge from three sampling sites in the river, and the results were presented as four seasons. A total of 45 Cyanophyta taxa were identified in the three orders. Order: Chroococcales 11%; Order: Oscillatoriales 64%; Order: Nostocales 25% dominance of Oscillatoriales from the second site, and the highest number of species recorded in the autumn. The study showed clear differences in the total number of algal species attached to different sites. The study was able to add a new record species to the Iraqi algae flora, which is Lyngbya sordida Gomont.

The Cure for Smallpox

The Cure for Smallpox Florence MacDonald (bio) Jenner—that's his name, Eric decides. It feels as if he's been trying to remember for days, and now he's got it, he's quite pleased with himself. But he can't remember what Jenner did; it has something to do with smallpox, that much he knows. Smallpox has been around for thousands of years, he remembers that too. But is it gone now, completely? He wishes he had time to look that up, but there's another contagion to confront now, travelling at the speed of hundreds of miles per hour, if it happens to catch a jet plane. Whereas the plague, he reminds himself as he straightens his tie and charges down the hospital corridor, travelled at twelve miles per day. On foot. He woke up this morning feeling muzzy, that was his mother's word for it. Trying to find his sea legs, his father would say. The last time he felt surrounded by disturbing and dangerous facts he was a senior resident, in his final year at a teaching hospital. He was on call, and without sleep of any restorative value for forty-two hours. He remembers being called to the ER where a young woman has just arrived by ambulance. Joyriding with her boyfriend, they hit a concrete abutment at one hundred kilometres an hour. Her boyfriend, perhaps mercifully, died instantly, but she has arrived with both femurs telescoped into her hips—not having worn her seat belt—the skin and bone of her cranium peeled back like the lid on a can of sardines, her skull open to expose her brain. It was Eric's job to medically stabilize this woman, this girl, and prepare her for the OR. But in his sleep-deprived state, he watched as the room turned a sparkly pink and the young woman sang like Joni Mitchell, a song about quitting this crazy scene. He joined her with his deep baritone—he had to—as the ER staff escorted her on a stretcher towards the OR. He's not entirely sure this happened, so he's never told a soul. Eric stops in the hall to have a conversation with a medical colleague whose name he can't remember. This man wants to be the next chief of staff for internal medicine. Eric too is applying for the position. His adversary is competitive in ways Eric cannot contend with: he jollies the nurses, makes them feel warm and cozy. Eric must remain on his toes. Sparkly. It's his turn to present at grand rounds this week but he doesn't have his [End Page 114] presentation ready. He plans to present a patient with adult Still's disease, a patient whose high, undulating fevers were being treated as malaria, so his swanning in with the correct diagnosis was something of a coup. But he hasn't got his slides ready for the presentation. Slides? How many times has Ronnie reminded him that he uses power point now? Why can he not remember? He shakes his head and a band of pain arcs from ear to ear like a headset playing horrible music. Were he and Ronnie supposed to go out to dinner tonight? That will have to be cancelled. Or was it last night? The last time they ate out was months ago, what with this virus swarming. Its mutations use Greek names like a pedigree, spreading themselves around like warm butter. He is swamped with work. He's in a swamp, sweating profusely. The air conditioning in this ancient wing of the hospital—slated to be torn down for a towering initiative involving space age technology—is about as effective as a thimble in a sinking boat. His colleague-slash-competitor is back: Eric proceeds to impress him with facts about the history of contagion. "Leprosy. Infecting the world for millennia." He talks about his time at the leprosarium in Carville, Louisiana. "An antebellum property, separated from the Mississippi River by wide, grassy levees. The last leprosarium in the world. It's gone now." He fails to make an impression. He should have followed Ronnie's suggestion...

Relationships Between Concrete Tester (CTS02v4) and Ultrasonic Pulse Velocity in Determining Quality of Concrete; a Case Study of Atimbo Bridge in Nigeria

The research examines the relationship between the use of a concrete tester (CTS02v4) and ultrasonic pulse velocity (UPV) based on the strength characteristics of the Atimbo bridge in the cross-river state of Nigeria. The best fit approach for the cts02v4-UPV relationship under various circumstances is developed by carefully analyzing the correlation between these data sets. As a result, the relation between concrete strength and the CTS-UPV formula is developed by this investigation. From the technical investigation, the residual compressive strength of the concrete abutment was found to be between 29.0 N/mm2 and 40.0 N/mm2. This value is still within the range compared to the expected design value of about 40 N/mm2. The cover to the reinforcement of certain capping beams has an outline of reinforcements, which signifies poor concrete cover, and the mean compressive strength is less than 20 N/mm2. The objectives of this paper are to increase the understanding of processes and the applicability of versatile equipment by making comparisons between the experimental results for both the concrete tester (CTS02v4) and the ultrasonic pulse velocity (UPV), which were used to evaluate the structural integrity of the Atimbo Bridge. Comparisons were made between the UPV method and the concrete tester method using statistical analysis.

Structural performance of perforated steel plate-CFST arch feet in concrete girder-steel arch composite bridges

This paper investigates the mechanical behavior of perforated steel plate-concrete-filled steel tubular (P-CFST) arch feet in concrete girder-steel arch composite bridges. A total of thirteen arch feet specimens, varying testing parameters of the length, thickness and arrangement of perforated steel plates, and the wall thickness of steel tubular, were prepared and tested. Failure modes, load-slip curves, strain history, and ductility of the P-CFST arch feet were presented and discussed. Experimental results indicate that introducing perforated steel plates to traditional CFST arch feet prevented the early-age cracking of the concrete abutment, and the P-CFST with triple-line-shaped perforated plates gave the largest resistance among all specimens. Compared to the P-CFST using a 4 mm-thick perforated steel plate, the cracking resistance of the P-CFST with a perforated plate thickness of 5 mm and 6 mm were increased by 26.9% and 69.4%, respectively, while the improvements for the ultimate resistance of the structure was not obvious. It also magnifies that the cracking resistance of the P-CFST using a 5 mm- and 6 mm-thick steel tubular was increased by 24.3% and 32.9%, respectively, compared to those with a 4 mm-thick steel tubular. Moreover, an analytical model considering the end-bearing effect of the combined tubular-to-plate steel member, the supporting effect of the SRC core column, and the shear effect between the SRC core column and surrounding concrete to predict the capacity of the P-CFST arch feet was proposed. The capability of the developed model was verified by experimental results.

A parametric study on the cost optimization of a reinforced concrete abutment using a genetic algorithm

This paper presents the cost optimization of a reinforced concrete abutment of a cantilever type using a genetic algorithm (GA). During the optimization process, six design variables, including two geometrical design variables and four cross-sectional design variables, were considered. The objective function consists of the cost of steel, concrete, and labor. Computation programs have been developed in JAVA to find an economical design adhering to Indian Road Congress (IRC) standards. To get an optimal solution in reasonable computational time, an attempt is carried out to evaluate the optimal GA parameters for the abutment model. A parametric study was conducted to understand the effect of the angle of friction, grade of concrete, and height on the cost optimization of the abutment. From the parametric study, it is observed that optimum cost of the abutment is obtained with a higher value of the angle of friction and concrete with a lower compressive strength. The results of the optimization are further discussed in detail.

Расчетное обоснование сооружений примыкания батопорта сухого дока с учетом поэтапности возведения и комплексных нагрузок

The article presents the results of calculated studies of the strength of the abutment structures of the floating dam of the dry dock. The calculated studies were carried out on the basis of the spatial finite-element model of abutment, in which there were simulated the enclosing walls of the pipe sheet pile, reinforced concrete abutment, soil of the base and filling. The results of stress-strain state and strength calculations have shown that the maximum displacements of the structures, stresses in the pipe sheet pile, ground anchors and reinforcement do not exceed the maximum permissible values. On the basis of the computational studies performed, the abutment structures of the floating bulkhead were substantiated. The abutment of the floating bulkhead to the dry dock structures serves to support it and transfer the pressing forces of the floating bulkhead to the ground. The enclosing abutment structures of the floating bulkhead are designed as vertical walls made of pipe sheet pile with a reinforced concrete abutment structure in the upper part. To ensure strength, a traditional solution was adopted with the anchoring of the pipe sheet pile with steel rods and ground anchors. To create a waterproof circuit, the project provides for the deepening of the pipe sheet pile into the rock base, the filling of the pipe cavity with concrete, welding of the locks with a metal plate with the filling of the cavity with polymer resin.

Holistic Life‐Cycle Analysis of Bridge Solutions

AbstractSteel in bridge constructions is often associated with very large span bridges due to its favorable relationship between strength and weight. But even for bridges with small and medium spans of up to 60 m, steel combined with concrete as a composite bridge can lead to economically justifiable constructions, especially when the performance during the complete life‐cycle is integrated. In this paper, two life‐cycle oriented calculation methods (life‐cycle costs and external costs) are introduced and applied. As a result, comparisons between two abutment solutions (conventional reinforced concrete abutment and a permanent steel sheet pile abutment) and two superstructure variants (steel composite construction and in‐situ prestressed concrete superstructure) are presented. It is shown that accelerated construction processes, durable materials, and a smart bridge‐design considering actual technological developments lead to economically advantageous solution for traffic infrastructures.

Studying and applying bim in the design automation of reinforced concrete abutments bridge according to TCVN 11823:2017 standard

The article mentions the research and application of intelligent information management systems in project implementation steps from design to construction. Use modern computer software to simulate building details on 3D models, intuitive and easy to control. Researching the current modeling technology in construction, thereby serving as the basis for the application of BIM model in the design of reinforced concrete abutment according to TCVN 11823: 2017 and detecting conflict in construction. The topic resolved a real project by using the BIM process following the required technical standards, thereby evaluating the applicability and analyzing the advantages of the model in project information management.

Experimental study of a geosynthetic-reinforced soil bridge abutment

The article presents an experimental study of a geosynthetic-reinforced soil (GRS) bridge abutment (BA). The BAs are seated on a saturated soft foundation layer and support a 16 m long concrete bridge. Laboratory tests were conducted on the foundation soil, geogrid, and fill material. The BA is constructed from 14 geogrids and has a total height of 4.2 m. The strain values in the geogrids were measured and recorded during the construction of the abutments and after installation of the bridge structure. The test results show that more than 50% of the total strain in the geogrids was developed during the construction of the BAs, mostly embedded in the ground. The remainder of the measured strain was a consequence of installing the prefabricated bridge girders, back fill placement, concreting the top slab, and placing the asphalt concrete. The strain distribution along the geogrids shows that the maximum strain was recorded below the sill, and was 50% higher than at the center of the BA. Based on an analysis of the construction costs, it can be concluded that conventional reinforced concrete abutments could cost up to five times the amount of optimally designed GRS-BAs.

COMPARISON STUDY ON THE DYNAMIC RESPONSE OF REINFORCED CONCRETE ABUTMENTS

Abutment performance suggestively impacts the seismic response of bridge constructions. This research investigates the dynamic performance of reinforced concrete abutments in the actual bridge construction with the consequence of the wing wall and movement constraint. The concrete box girder bridge's analytical model was implemented from the actual bridge in Japan, with the numerical model was performed by a 3D finite element model in ABAQUS software. Four distinct abutment modeling approaches were carried out, including abutment without wing wall as Type 1, an ordinary abutment form in Japan as Type 2, abutment with the entire wing wall as Type 3, and the proposed model Type 4. Comparison study will be taken for different positions of input ground acceleration, which were applied horizontally at the bottom of the pier and abutments as Type A, and at the bottom of the pier as Type B. The input seismic motion was Level 2 Type 2 with ground Type I. The results confirmed that the input seismic ground acceleration position resulted in the different response on shear stress and response stress of abutment. The response stress of abutment with 20 cm of the gap is less than 10 cm. Besides, abutment Type 4 has the capability of resisting the flexural load due to strong ground motion.

Bridge assessment: A case study of Ajaokuta-Itobe Bridge, Kogi State

This report summarizes the assessment carried out as a result of the public uproar on the degree of safety of the Ajaokuta/Itobe Bridge in Kogi state. The public outcry was as a result of a severe damaged expansion joints of the bridge. Visual inspection and concrete strength test were carried out to ascertain the safety condition of Itobe Bridge. Seven out of the total number of eight expansion joint covers were damaged and out of place while all the elastomeric bearings were in good working condition. The scouring of the river bed was not visually pronounced except little at the abutment side of the Abuja-Ayingba approach which is attributed to change of water course. Farming activities within the vicinity of the bridge embankment has no effects on the bridge foundation. The compressive strength test result of some bridge elements selected shows that the values are within the satisfactory range. The assessment recommended the lengthening and desilting of the drainage pipes to prevent further corrosion of the concrete and steel members. The use of sand blasting and repainting of the steel beams was also recommended to protect them from further corrosion. Maintenance of cracks on the reinforced concrete abutment and piers should be carried out. The use of sheet piles filled with compacted sand or gabions around the exposed piles caps to protect the foundation was recommended. Shoreline protection measures should be used in protecting the bridge eroded embankment. Seven out of eight expansion joint devices were damaged therefore exposing the elements of the structure that are otherwise protected by the joint devices. The openings about 47cm-53cm becomes a conduit by which moisture, abrasives, chemicals, and other debris are deposited on the superstructure and substructure below the opening, thereby causing extensive damage. The expansion joints devices should be fixed with proper elastomeric strip seal to protect the bridge from further deterioration.

Temperature and Strain Monitoring Analysis of Self-Compacting Concrete Bridge Decks with Mechanized Sand

The temperature control of self-compacting concrete with machine-made sand is an important research element related to the safety of actual projects. A reasonable and feasible temperature and strain monitoring scheme was designed for the bridge abutment project of Honghezhou Special Bridge in Yunnan Province, and the monitoring results of the concrete abutment on site were analyzed. The results show that the temperature of self-compacting concrete with mechanism sand has the characteristics of large temperature rise and rapid cooling compared with ordinary concrete, and the concrete surface layer is prone to cracking from 1.5d to 4d of age, and the concrete foundation part is prone to cracking at about 9d of age. It can provide reference for the temperature crack prevention and control of similar mechanism sand self-compacting concrete projects.

Abutment Failure and Remedy in Gombe State Nigeria

Fixed and free ends Abutment is a significant issue affecting the overall reliability and safety of a Bridge structure if not design and constructed as functioned. However, despite considerable consequences, potential functionalities of abutments in bridge structure are usually not fully considered and so abutments are generally designed as free end elements. The research presented in this paper, aimed to develop a better understanding of free and fixed ends abutment stability from both analysis and design point of view. This paper includes a case study of a Kwadon Liji Kurba bridge (GPS N10° 16.642ʹ E11° 13.520ʹ), located at Gombe-Biu road in Gombe, Gombe state Nigeria, which was shot down for traffic used due to abutment failure. This paper presents a full result on bridge abutments analysis and design. Moreover, a systematic methodology was implemented, to identify potential remedial options for treatment of abutment movement. Considering similar loading condition as exited bridge, analysis shows a moment maximum of the fixed abutment to be 1748.79kNm and minimum moment at fixed end to be 631.08kNm and the free end abutment has a maximum moment of 2059.02kNm. The moment is considerable large and will result to reinforcement design rather than just mass concrete abutment as in the existing bridge. The pressure exerted by the abutment was 422.35kNm 2 maximum and FS against sliding of 2.8. Unless the bearing pressure of the soil greater than that, earth movement is unavoidable and so pile foundation should be used instead of spread footing.

An orthogonal component method for steel girder-concrete abutment connections in integral abutment bridges

To predict the moment – rotation relationships of steel girder-concrete abutment connections with perfobond connectors, this paper develops an orthogonal component method, which is modified from the conventional component method. The connections were first disassembled into several horizontal and vertical components, and these components were simplified into translational springs. Next, the equations for the mechanical properties of each spring were determined with analytical analyses, and were calibrated against a number of numerical models. The springs were then reassembled and further simplified into two parallel rotational springs to calculate the rotational stiffness, the yield moment and the yield rotation of the girder-abutment connections. Finally, based on the Ramberg and Osgood model, the moment-rotation curves of the connections were determined, and were compared with numerical and experimental results. The results show that the proposed method is feasible to predict the rotational behavior of the girder-abutment connections, and can achieve fair accuracy in most cases when the shear deformation of concrete abutment is considered. The proposed method can also predict the shear force distribution among perfobond connectors. The main feature of the proposed method is that it can incorporate the contribution of perfobond connectors and vertical forces in the connections.

Evaluation of Passive Soil Stiffness for the Development of Integral Abutments for Railways

An integral bridge, which is constructed without expansion joints and bearings, is an economical technology that permits slender abutment and footing design to decrease the associated maintenance and construction costs. In this study, a geosynthetic reinforced integral abutment (IA) for railways and a conventional reinforced concrete abutment (CA) are modeled, considering the two types of foundations, using the finite element method. The passive soil stiffness of the foundations was evaluated through the application of a uniform horizontal load in four separate models. The passive soil stiffness of the IA model is approximately 70% of that of the CA model. Additionally, we confirmed that the passive soil stiffness was affected by changes in the thickness of the abutment, size of the footing, number of installation piles, and elastic modulus of the ground.

TORSIONAL STIFFNESS AS AN INFLUENCE PARAMETER ON ARCH STABILITY

Arch bridge springs can be connected to concrete abutments either by prestressing bars or by connectors. In both options, the torsional stiffness is substantially reduced, compared to the full arch cross sectional area. The influence of this lack of torsional stiffness on arch buckling is being researched, both numerically and experimentally. To reduce any residual stress during tests, wooden rods that simulate the arch were submerged in water and subsequently bent to the desired shape. Imperfections of the arch samples are measured. Two unequal concentrated loads are applied to the samples, thus simulating the effect of movable loads across half of the arch span. During loading, lateral deflections were measured until elastic buckling occurred. The simulation of more flexible rotation of the springs required replacing the cross section by thin equivalent side plates. Since all parameters have not been isolated, the results are limited yet. However, comparing the failure load of similar conditions, the reduction of torsion stiffness by 81.48% reduces the failure load by 26.3%. This indicates that total prevention of axial rotation may not be imperative for arch bridges.

Supports for Repair Gates at the Lower Bureya Hydroelectric Power Plant

The monolithic concrete abutments as supports for the repair gate made by underwater concreting at a depth of up to 21 m in a permanent formwork fixed to the concrete spillway structures are described.

Evaluation of Bridge Abutment with Ultraseismic Waveform Tomography: Field Data Application

This paper presents an application of ultraseismic waveform tomography for condition evaluation (determination of elastic properties) and the unknown depth of a concrete bridge abutment. A newly developed waveform tomography technique for bounded medium (e.g. thin plate) was applied to an ultraseismic dataset collected on a 30-m long bridge in New York City. The dataset was measured on the top of abutment using 24 100-Hz vertical geophones uniformly spaced at 1.2 m apart, and a 3-lb hammer source to induce wave energy. The results revealed that the waveform analysis was able to characterize both the S-wave and P-wave velocities (Vs and Vp) of the abutments and the supporting soils. The true abutment depth of 5.7 m was generally identified in both inverted Vs and Vp profiles. The main advantages of this approach include: (1) data acquisition on top of the abutment is more convenient and cost effective compared to measurements from the ground, boreholes, or river-beds for water bridges; and (2) abutment concrete physical elastic properties are characterized at high resolution in cells. To our best understanding, this is the first reported study using the waveform tomography on field data for assessment of concrete abutments or wall-type structures.

The Sundsvall Bridge, Sweden

ABSTRACT:Sundsvall is located approximately 400 km north of Stockholm on the Eastern coast of Sweden as neighbour to the Bothnian Bay. The Sundsvall Bridge presently under construction will cross the Sundsvall Fjord and is a missing link in the north south motorway E4 from Stockholm along the Bothnian Bay. The Sundsvall Bridge has a total length of approx. 1.4 km between the concrete abutments. It is designed as a continuous girder bridge with a modern closed box girder cross section. A special feature for the Sundsvall Bridge is a very complex geometry, due to the curved alignment – horizontally as well as vertically. Further a varying width and a varying height of the bridge girder together with a one‐sided slope contributes to the complexity.

DESIGN OF PERKUWEN BRIDGE PART WAY LONG IKIS-LAMBAKAN PASER TANA PASER REGENCY PROVINCE EAST KALIMANTAN

Long Kali is a sub-district of Paser Tana Paser Regency Prov. East Kalimantan. In this sub-district have two village separate by a river, that is Perkuwen river, there is bridge has a broke. Whereas the village very needed a bridge because it is used as a transportation infrastructure for peoples and also passed by vehicles transporting oil palm yields . Therefore, the design of composite bridges made with spans 25 m and 7 m wide bridge.In this plan the analysis of Standard methods of loading refers to the bridge imposition For RSNI T-02-2005 about composite bridge structure design method, refers to RSNI T-03-2005 about Steel Structural Design For Bridge, SNI 03-1729-2002 about Steel Structures Planning Procedures and SNI 03-2847-2002 about Concrete Structures Calculation for Building.The result is used the main girder profile SH 950 x 400 x 16 x 32 and diaphragm WF 400 x 200 x 8 x 13. Vehicle floor plate thickness 20 cm using quality concrete 30 MPa and quality reinforcing steel reinforcement 360 MPa with subject dividers reinforcement D22- 100 and D12-100 mm. In using concrete pavement 30 MPa D22-100 mm staple reinforcement and shear reinforcement rebars quality D12-100 mm 360 MPa. Concrete abutment in the form 25 MPa at 2 m height and length of 8,5 m. Steel pipe pile foundations quality 25 MPa are 16 pieces with a length of 10 meters and a diameter of 0.4 m.Keyword: Bridge, composite, steel pipe pile.