Health Monitoring of Mundhwa Bridge

Bridges are the critical component of the transportation infrastructure. Regular inspections and maintenance are the essential components of any bridge management program to ensure structural integrity and user safety. This is a grand challenge due to enormous number of existing bridges. Health monitoring of bridge concept is widely applied to various forms of infrastructure, ranging from bridge to skyscraper. Health monitoring is used for detecting the existence of damage on the infrastructure, locating the damage, identifying the types of damage and quantifying the severity of damage. The area of health monitoring process that receives the most attention in the technical literature is the identification of data features that allow one to distinguish between the damaged and undamaged structure

The transportation infrastructure is quickly aging. Traffic and variable loading conditions greatly influence the performance, durability, and safety of the bridge structure throughout its service life. Continuous monitoring can provide basis for determining the deterioration rate and for estimating the remaining service life, thus assisting in making important decisions regarding bridge maintenance. Bridge engineers need a reliable way to assess structural integrity of bridges to maintain the continuous operation of the road network while ensuring the safety of the public. Traditional visual inspection techniques are both time consuming and expensive. They are also qualitative and can only assess outward appearance. Any internal damage may go unnoticed for a long period of time. Many old highway bridges are rated as structurally deficient or obsolete. How does a bridge engineer keep track of these problems? Are inspections conducted every other year enough? A possible solution to these issues is to conduct health monitoring of bridges. This technique can detect changes in bridge superstructure and in some cases predict impending failures.

In India many of bridges was constructed during the period of 1950‟s i.e. the age of bridge is more than 55 years. The maintenance of bridge was not carried out compared when compared to other western countries. Due to infrastructure development and heavy traffic, the bridges are subjected to very high dynamic loadings. To avoid collapse of bridge it is mandatory to assess the condition of existing bridge.

This is where health monitoring of bridges has a role to play. It gives a way to overcome these drawbacks with minimum damage and loss. This report provides an overview of the issues related to the inspection, condition assessment, evaluation and maintenance of highway bridges. Thus, the condition of bridge can be determined my various health monitoring techniques.

2.1 Masoumi [2013] [1] In some countries, collapse of bridges initiated the formal requirements for the inspection of highway bridges. This paper discusses visual inspections of 200 reinforced concrete bridges in Turkey and non-destructive testing applications performed on 10 bridges, which were most deficient. Penetration resistance, ultrasonic pulse velocity, rebar locating and reinforcement corrosion tests are performed on decks, piers and beams of reinforced concrete bridges and the results are compared with the results of visual inspections. 2.2 Mr. S.N. Ahmed (2015) [2] the process of implementing a damage detection and characterization strategy for bridges is referred to as health monitoring of bridges. Here damage is defined as changes to the material or geometric properties of structural system which adversely affect the performance of bridges. Many of the reported collapses of in-service structures can be attributed to strength degradation caused by environmental stressors. In recent studies deteriorating bridge structures under various environmental stressors have been evaluated in a reliability context. There are several degradation mechanisms are present in concrete highway bridges as, sulphate attack, alkali-silica reaction, freeze-thaw cycle attack, and corrosion, etc. 2.3 Azlan (2006) [3] This paper presents a non-destructive testing method in evaluating bridge condition in comparison with visual inspection that has been used for ages. While condition ratings are all qualitative and defined primarily as sets of visual indicators in routine inspection, non-destructive testing are more quantitative and has large potential in determining damages inside the structure that are not visible. 2.4 Ann Maria Johnson (2016) [4] The case study from India determines the quality and strength of a T-beam girder bridge. 75 concrete bridges under the supervision of Public Works Department, Malaysia and 10 out of 200 reinforced concrete bridges (i.e. 10 most deficient bridges) in Turkey were selected to determine the strength and to establish a correlation between visual inspection rating and the non-destructive testing results. The investigation shows that the use of non-destructive testing methods can help reduce the allowing inspectors to locate damages earlier. The studies also show that Ultrasonic pulse velocity Test is the ideal NDT method to predict the deterioration in the structures and to determine the service life of the structures. And there exists a correlation between results of non-destructive tests and condition states based on visual inspections. 2.5. Piyush K. Bhandari [2016] [5] Bridges are the most crucial members along lifelines of nation. The bridges constructed along road and rail network must be in sound intact condition and must be inspected periodically to keep it in working condition. Bridge inspection is generally conducted through visual inspection or structural analysis. Most common is visual inspection method. But is can show only surface defects. In case of internal defects, it shows limitations and may depend on experience of Investigator. Non-destructive testing (NDT) method has proved to be a noble solution on this issue. It is widely used now a day for periodical inspection of bridges. NDT results can help to estimate the quality and strength of existing bridges that deteriorate with time and finally result into failure. Advanced testing methods can decide repairs & maintenance plan or complete replacement of bridges. 2.6. James bader [2008] [6] Nondestructive evaluation (NDE) is a means of evaluating structural components without damaging them. It can be used to evaluate structural systems, as well as specific structural components. Nondestructive testing is particularly useful for evaluating in-service bridges, since the bridges can remain intact and open to traffic during the inspection and evaluation period. The NDE methods discussed in this paper include visual inspection, eddy current method, radiographic testing, and manual and automated ultrasonic testing. The Federal Highway Administration‘s NDE Validation Center performs extensive research on a number of these NDE methods.

[1]. To study Health Monitoring system for Mundhwa Bridge [2]. To ensure bridge safety and to identify its damages or deterioration. [3]. It helps to improve the knowledge on various health monitoring techniques used in bridges. [4]. This technique will extend the lifetime of deficient bridgemethod can monitor bridges

problems to avoid tragedies. [5]. It optimises operation and maintenance costs.

Health monitoring is used for detecting the existence of damage on the Mundhwa Bridge, locating the damage, identifying the types of damage and quantifying the severity of damage. Site location: Mundhwa Bridge over Mutha River, Pune. Table -1: General Description

49830 PCU. [Source: Traffic Forecast for the Proposed Metro Rail Project in Pune Metropolitan Area by Transportation Systems Engineering Group, Civil Engineering Department, Indian Institute of Technology Bombay, Powai, Mumbai] [a] Approaches: The approaches are in good condition. [b] Protective works: There are no protective works like pitching or flooring or toes or aprons.

[a] H.F.L.:RL 539.920 m [b] Inadequacy of waterway:By local enquiry it is ascertained that the bridge is not overtopped in floods. Therefore, waterway below the bridge is adequate. [c] Erosion of banks as evident:No erosion is observed.

At Pier No.1 from the abutment on kharadi side the river bed is nearly 4.5m below the ground level, therefore the pier is subjected to one sided earth pressure, this will have to be strengthened. Buttresses are required on the river side on Pier No.1. It is difficult to excavate and study the foundation. But there is no settlement or tilting of the foundation. It was difficult to ascertain the depth of foundation. However, since many bridges are in progress in the town,has investigated the foundation levels. These are found to be within 3 m below the bed level. However, in some cases the maximum depths are found to be 6 m. In large river bridges, exposed rock is also available.

RCC roller rocker bearings are provided. The bearings are in very poor condition.

[a] Concrete [RCC and PSC]:No deflection in the deck appears anywhere. There are minor surface defects in concrete. From the surface it appears that earlier there was stone masonry which has been plastered which can be verified by opening a portion of masonry and removing plaster. [b] Steel: Not applicable. [c] Masonry Arches: Not applicable.

good. [b] Drainage: Water spout pipes are being clean; some pipes are existing and others are gone. [c] Parapets and handrails etc.: Initially the steel railing was continuous over the joint later the pipes were cut to make a joint at expansion gap. [d] Footpath: The kerb at the footpath is damaged. [e] Expansion joints: Concrete at the expansion joint is deteriorated. Whenever the vehicles travel over the bridge, a thudding sound coming from the expansion joints & bearings indicating upward or downward or longitudinal movement, due to movement of joint. It is not merely a sliding phenomenon. The vertical movement is more prominent. Initially the steel railing was continuous over the joint later the pipes were cut to make a joint at expansion gap. In the service pipe line there is one expansion joint, gap for expansion does not appears to be adequate. [f] Utilities: There is a pipe line passing from the centre of the bridge. Which also acts as a median. Pipe line has leaked and this has cause several damages, it is therefore advisable to have arrangement at the joints in pipe to collect leaking water & let it be released out. In the pipe line there is one expansion joint, gap for expansion does not appears to be adequate. There is another service line going over the footpath which is not covered. A service line is passing outside the railings, fixed to the bridge by steel brackets.

Image-(b): service lines in footpath are not covered

Image-(c): Expansion joint are to be damaged

Image-(d): Damaged bearing

Image- (e): damage to the structure at bearing location

Image- (f): Damage in deck slab, steel is open in slab

[1]. Velocity below 3.00 km/sec indicates ―DOUBTFUL‖ quality concrete. [2]. Velocity between 3.00 to 3.50 km/sec indicates ―MEDIUM‖ quality concrete. [3]. Velocity between 3.50 to 4.50 km/sec indicates ―GOOD‖ quality concrete. [4]. Velocity above 4.50 km/sec indicates ―EXCELLENT‖ quality concrete.

[1]. The width and the span being equal there is expansion and contraction in central and longitudinal direction, however the bearing and expansion gaps are designed only for longitudinal direction. It is therefore necessary to provide such type bearings and expansion joints which can move in both directions i.e. and strip seal expansion joints are ideal for such situations. [2]. Replace the bearings by POT-PTFE bearings as RCC roller rocker bearings are not permitted by MORTH, since many such bearings have cracked. [3]. All expansion joints are to be replaced by strip seal expansion joints. [5]. The kerb should be replaced by M25 concrete RCC kerb and 75mm thick flooring of M35 concrete is to be provided over the footpath. Better to accommodate services in footpath zone. Tiles should be provided on the footpath. [6]. A cover should be provided over the water spouts and a pipe projecting from there is required at all water spout locations. [7]. The service line going over the footpath should be covered.

Health monitoring of bridges are most important since most bridges are becoming old, assessment of bridge condition using non-destructive tests and visual inspection can be used for that purpose. This technique will allow inspectors to get a more accurate view of the condition of the bridge and to locate damage earlier. To save the human life's by warn earlier to any tragedies. The above result shows that the pulse velocity is between 3.61 to 4.28 km/sec means that good quality concrete at damage location. Through, the ultrasonic pulse velocity test indicates good quality of concrete, but the visual observation indicates that their major construction damage. By visual inspection it shows that water line passing through the centre line of bridge, its harmful to traffic movement, need to be shift.

Ann Maria Johnson (2016). ―Evaluation of Bridge Performance Using Non-Destructive Testing - A Review‖, International Advanced Research Journal in Science, Engineering and Technology Azlan Adnan (2006). ―BRIDGE EVALUATION THROUGH NONDESTRUCTIVE TESTING

Construction Conference (APSEC 2006), 5 – 6 September 2006, Kuala Lumpur, Malaysia. F. Masoumi (2013). ―Condition Assessment of Reinforced Concrete Bridges by Combined Non-destructive Test Techniques‖, IACSIT International Journal of Engineering and Technology James Bader, Nondestructive Testing and Evaluation of Steel Bridges, ENCE 710, spring 2008. Mr.S.N. Ahmed (2015). ―Health Monitoring of Bridge‖, International Journal of Innovative Research in Science, Engineering and Technology Piyush k Bhandari (2016). ―Advanced NDT Methods for Evaluation of Bridges‖, International Journal of Advance Research in science engineering. Vol. no.5. Issue no.9, September 2016.

P.G. Student, Padmabhooshan Vasantdada Patil Institute of Technology, Pune, Maharashtra, India