JP2016075090A - Expansion joint system for bridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an expansion joint system for a bridge that appraises integrity of an expansion joint and a bridge body affected by a traffic load, for performing maintenance, replacement and other work at an appropriate time for the bridge body and the expansion joint.SOLUTION: A joint gap A is formed in a bridge axial direction on a floor slab part of a road bridge, leaving an interval. A pair of face plates 7, 7 and a strain measurement sensor 10 are installed on the joint gap A, the pair of face plates constituting a finger joint 4 flush with a road surface of the floor slab part, and the strain measurement sensor measuring displacement and strain caused by a wheel load on the face plates 7, 7. The strain measurement sensor 10 monitors displacement at a tip of the face plates 7, 7, and strain at a root part of the face plates. Integrity of the finger joint and a bridge body is appraised based on the monitoring result. Monitoring by a monitoring camera 11 is also performed.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an expansion joint system for a bridge, and by monitoring the deformation (displacement, strain, etc.) of the expansion joint installed in the floor slab part of the road bridge, the expansion joint and the bridge body (floor part and The soundness of the bridge girder that supports the floor slab part is evaluated, and maintenance and replacement of the bridge body and expansion joints can be performed at an appropriate time, and the bridge body can be replaced.

  In general, bridges such as road bridges are mainly composed of steel girders and PC girders in the superstructure, and the floor slabs are constructed with concrete floor slabs such as RC slabs or PC slabs, Or it is comprised by methods, such as placing concrete in a steel formwork.

  In addition, bridge girders and road slabs are repeatedly expanded and contracted due to seasonal temperature differences and drying and shrinkage of concrete, so a gap is provided at an appropriate interval in the bridge axis direction, and an expansion joint is installed in the gap. The As expansion joints, rubber and metal product type expansion devices and cantilever steel finger joints are mainly used.

  For example, Patent Documents 1 and 2 and Non-Patent Documents 1 to 7 are available as prior art documents related to the telescopic device. Patent Documents 1 and 2 disclose inventions relating to a bridge extension device and a fixing structure of the extension device.

  Non-Patent Documents 1 to 3 describe fatigue damage in a conventional steel telescopic device. Non-Patent Documents 4 to 6 discuss structures related to fatigue durability of an expansion / contraction device in consideration of damage cases such as Non-Patent Documents 1 to 3.

  By the way, even if it is a steel bridge or a concrete bridge, if proper maintenance is not performed at an appropriate time, fatigue cracks, corrosion, cracks, etc. will develop, which will lead to a decrease in strength, and eventually aging. Rapid progress can lead to damage and collapse.

  In particular, when the expansion joint is damaged in the joint part of the floor slab part, rainwater and water containing salt contained in the antifreeze material along with rainwater leaks to the lower side of the floor slab part along the loose part. As a result, the end of the bridge girder supporting the slab will be damaged and the life of the bridge body will be shortened.

  For this reason, it is required to maintain economically and rationally while ensuring safe and smooth traffic in the future. To that end, it is necessary to efficiently acquire data necessary for bridge maintenance. It is important to properly grasp and evaluate the current state of bridges and to perform planned maintenance based on them.

  Conventionally, in order to obtain the data necessary for grasping and evaluating the current state of the bridge body, close visual inspection is mainly used, and investigation is performed using simple inspection machines and equipment as necessary, and the degree of damage is further detailed. Non-destructive inspection is also used as necessary to investigate damage that cannot be detected by visual inspection from the surface.

  In particular, in understanding the soundness of the bridge body, it is important to understand the traffic volume of large vehicles. Since 2002, steel bridges have been designed to prevent fatigue damage in the design life since fatigue design for live loads has been introduced and analytical methods that can calculate fatigue life have been taken. However, the problem of overloading large vehicles is serious, and there are cases in which fatigue cracks occur in years shorter than the fatigue life assumed in the design, and the soundness of the bridge body is significantly reduced.

  For this reason, if the actual traffic load data after road use can be acquired, the life prediction of the actual bridge body can be performed more accurately.

  Bridge members that can directly measure the traffic volume of large vehicles are pavements, floor slabs, expansion joints, etc. that are directly subjected to load, while pavements and floor slabs are widely distributed on the surface, while expansion joints are In the case of a steel cantilever finger joint, it is possible to estimate the traffic load in principle by measuring the strain and displacement of the bridge.

  In Patent Document 1, strain gauges are embedded in finger joints installed on the floor slabs of road bridges to capture the traffic frequency and load of road bridges, and to determine the fatigue process of bridges by traffic volume surveys and load value distributions. In addition, a road bridge expansion joint with a load meter that can be used for feedback to design load conditions is disclosed.

  In addition, when an earthquake with seismic intensity of about 4 or more occurs, the left and right bridges of the telescopic device may each have excessive seismic displacement, which may cause damage to the telescopic device and the tip of the steel cantilever finger joint. If the difference (step) is large, even if the bridge body is healthy, there are cases where it is difficult to open traffic after the earthquake due to a large step on the road surface. For this reason, it is necessary for a maintenance manager or an inspector to go to the site as soon as possible and visually check and determine whether or not the traffic can be opened.

JP 2004-143845 A Utility Model Registration No. 3164031 Japanese Utility Model Publication No. 04-119033 JP 2004-190264 A

Hiroshi Nishi, Takashi Aramoto, Shuhei Sakai, Shuichi Ono, “Fatigue test of steel finger joints”, 63rd Annual Scientific Workshop (2008), pp.145-146 Nagao Chiaki, Yonekawa Hideo, “Discussion on Damage of Steel Comb-type Telescopic Device on Tomei Expressway (between Numazu and Fuji)”, 63rd Annual Scientific Workshop (2008), pp.143- 144 S. Ono, S. Sakai & T. Imamura, “Fatigue evaluation of steel finger type expansion joints for highway”, IABMAS2010 (The Fifth International Conference on Bridge Maintenance, Safety and Management), pp. 3447-3452 Kenichiro Sasuka, Yukihiro Sana, Yasuhisa Tanaka, Masaki Iwasaki “Examination of Fatigue Durability of Improved Stretching Device”, 58th Annual Scientific Workshop (2003), pp.1303-1304 Yukihiro Sauna, Kenichiro Sasazuka, Yohei Koike, Masaki Iwasaki, “Examination of anchorage strength characteristics of improved expansion and contraction device”, 58th Annual Scientific Workshop (2003), Japan Society of Civil Engineers, pp.1301-1302 Kenichiro Sasuka, Akihisa Yanaka, Yukihiro Sauna, “Study on strength and durability of anchoring part of improved steel telescopic device”, Bridge and foundation (October 2004), pp.33-38 Nakanishi Fumio, Yoshida Tetsuya, Watanabe Yuki, Yoda Teruhiko, “Experimental Study on Aluminum Alloy Casting Stretching Device Using Perforated Gyber”, 59th Annual Scientific Workshop (2004), Japan Society of Civil Engineers, pp.1043 -1044

  However, the former method of grasping and evaluating the current state of the bridge mainly using a simple inspection machine / apparatus for close-up visual inspection is greatly influenced by the skill of the operator, so there is a problem that the objectivity is poor. there were.

  On the other hand, in the method disclosed in Cited Document 1, since the strain gauge is thinly processed on the steel plate at the tip of the finger portion and attached to the lower part thereof, the strain gauge is attached due to excessive shaking during an earthquake or the like. There is a possibility that the tip of the finger part is greatly deformed or that it is completely broken and cannot be measured. Moreover, since the thickness is thin, the measured value becomes large due to the decrease in the plate thickness in a corrosive environment, and there is a possibility that an appropriate value cannot be measured.

  Since the present invention is made to solve the above problems, by monitoring the deformation (displacement, strain, etc.) of the expansion joint installed on the floor slab part of the road bridge, For bridges that evaluate the soundness of the bridge body (the floor slab and the bridge girder that supports the floor slab part) so that the bridge body and expansion joints can be maintained and replaced at an appropriate time, and the bridge body can be replaced. An object of the present invention is to provide an expansion joint system.

  In general, the fatigue life of a bridge such as a road bridge is determined by the accumulated traffic volume. Therefore, the necessary maintenance management timing is estimated by measuring the actual traffic load distribution and performing reliable life prediction. It becomes possible to do.

  For example, the expansion joints installed on the floor slabs of road bridges are directly subjected to wheel loads, so if it is possible to always measure the displacement of the expansion joints and the distortion of the root, the cumulative load frequency distribution Therefore, the soundness evaluation of the expansion joint and the soundness evaluation against the fatigue of the rough bridge body can be performed.

  The present invention was made based on such an idea, and evaluated the soundness of the expansion joint and the bridge body from the deformation (displacement, strain, etc.) of the expansion joint installed in the web gap portion of the expansion joint. In the expansion joint system for bridges configured to be used, a strain measurement sensor that measures displacement and strain due to wheel load of the face plate that constitutes a finger joint flush with the road surface of the floor slab portion in the gap portion Characterized by being able to evaluate the soundness of the finger joint and the bridge body by monitoring the displacement of the tip of the face plate and the strain of the base of the face plate by the strain measuring sensor. Is.

  According to the present invention, the life of the finger joint and the fatigue damage of the bridge body are evaluated by monitoring the deformation (displacement, strain, etc.) of the finger joint that is directly subjected to the wheel load, whereby the finger joint and the bridge body are evaluated. Thus, it is possible to provide data for estimating the lifespan and performing maintenance of the finger joint and the bridge body at an appropriate time, or replacing the finger joint at an appropriate time, and further replacing the bridge body.

  The finger joint to which the present invention can be applied is not particularly limited, and can be implemented in a finger joint having a slightly unique form as long as the basic form (shape, etc.) is common. Needless to say.

  In addition, the strain measurement sensor is attached to the base of the face plate that constitutes the finger joint, so even if a part of the face plate is greatly deformed or broken due to excessive external force such as seismic force. The displacement of the face plate tip and the strain at the base of the face plate can be continuously monitored.

  In addition, for example, a highly durable optical fiber sensor can be used as the strain measurement sensor. In this case, a power source in the vicinity of the measurement point becomes unnecessary, and monitoring can be performed continuously.

  Furthermore, in addition to monitoring the deformation (displacement, strain, etc.) of the finger joint that is directly affected by the wheel load by the strain measurement sensor, it is a small-sized device for telescopic observation of the deformation (misplacement, etc.) of the finger joint itself. A surveillance camera is installed in the railing area of the railing to monitor the displacement of the face plate tip, the occurrence of a finger joint misalignment associated therewith, and the road surface conditions (water congestion, etc.) in the vicinity of the finger joint. Thus, maintenance and repair of the finger joint and its vicinity can be performed at an appropriate time.

  In addition, in the event of an earthquake with a seismic intensity of 4 or more, it is possible to quickly determine whether or not an emergency vehicle is allowed to pass by monitoring whether or not the finger joints are misunderstood or damaged.

  In addition, by installing a humidity meter on the back of the water-stopping member attached to the lower side of the finger joint and monitoring the wetness of the water-stopping member and its surroundings, damage to the water-stopping member and damage to the water-stopping member It is possible to estimate the degree of damage to the bridge girder end due to water leakage and to determine the necessity of replacement of the water stop member and replacement due to corrosion of the bridge end. There is a concern that damage to the end of the bridge girder will shorten the life of the entire bridge.

  In addition, these monitoring data are communicated wirelessly, stored in an observation computer or an external cloud data center, etc., and the data processing is performed. Time is reduced, and the soundness of the bridge body and the expansion / contraction device can be quickly determined for the monitoring data.

  According to the present invention, by monitoring the deformation (displacement, strain, etc.) of the finger joint directly subjected to wheel load with a strain measurement sensor or a monitoring camera, the life of the finger joint and fatigue damage of the bridge body are evaluated, It is possible to estimate the life of the finger joint and the bridge body and perform maintenance of the finger joint and the bridge body at an appropriate time, or to replace the finger joint at an appropriate time and to replace the bridge body. Therefore, it is possible to maintain and manage economically and rationally while ensuring safe and smooth traffic in the future.

It is the perspective view which showed one Embodiment of this invention and was seen from the upper direction of the expansion joint apparatus for bridges. It is the perspective view seen from the lower part of the expansion joint apparatus for bridges. It is a longitudinal cross-sectional view of the bridge axis direction in the joint part of the road floor slab which shows the expansion joint apparatus for bridges. It is a longitudinal cross-sectional view in the direction perpendicular to the bridge axis at the joint of the road floor slab and wall rail showing the installation position of the monitoring camera and the measurement box. FIG. 5 (a) is a perspective view seen from above, and FIG. 5 (b) is a perspective view seen from below, showing an example of a commonly used finger joint.

  1 to 4 show a bridge main body of a road bridge. A RC floor deck 2 is laid on a bridge girder 1 made of a steel girder or a PC girder. 3 is laid.

  A plurality of gaps A are provided in the road deck 2 and the wall height column 3 at intervals in the bridge axis direction, and all the gaps A are continuously provided in the direction perpendicular to the bridge axis. In addition, finger joints 4 are installed in each of the gap portions A of the road floor slab 2.

  The finger joint 4 includes a pair of web plates 5 and 5, a plurality of anchor plates 6, and a pair of face plates 7 and 7 and a water stop member 8.

  The pair of web plates 5, 5 are formed in a rectangular plate shape having long sides in the direction perpendicular to the bridge axis, and are respectively installed on opposing surfaces in the play space A. The plurality of anchor plates 6 are formed from perforated plates having long sides in the bridge axis direction, are installed on the back side of the web plates 5 and 5 at regular intervals in the direction perpendicular to the bridge axis, and the concrete of the road slab 2 Embedded deep inside.

  Further, the pair of face plates 7 and 7 are installed in a play portion A between the opposing web plates 5 and 5 so as to form a finger joint that is flush with the road surface of the road slab 2. Further, the end portion of each face plate 7 on the web plate 5 side is fixed in a cantilever manner to the upper end portions of the web plate 5 and the plurality of anchor plates 6, and the front end sides are engaged with each other with a gap therebetween. Forms a type of joint.

  The pair of web plates 5, 5, the plurality of anchor plates 6, and the pair of face plates 7, 7 installed in this way are integrally assembled by welding or the like (simple plate assembly structure), so that the low Costs are being reduced. In addition, because it is formed in a certain length in the direction perpendicular to the bridge axis (unitization), it is possible to shorten the traffic regulation time during maintenance and replacement by dividing construction.

  Further, the web plate 5, the anchor plate 6 and the face plate 7 are all installed vertically, and the end portions 7a of the face plates 7 and 7 are tapered so that the filling property of the concrete can be improved. ing. Further, since the anchor plate 6 is formed of a perforated plate, the integrity with the concrete is improved.

  The water stop member 8 is attached continuously in the direction perpendicular to the bridge axis so as to stop rain water and the like flowing from the gap between the face plates 7 and 7 and close the gap A between the opposing web plates 5 and 5. Yes. Moreover, it also has a dredging function for draining to a drain outlet (not shown) provided at the end of the road deck 2 in the direction perpendicular to the bridge axis.

  Furthermore, the strain measurement sensor for constantly measuring the displacement of the tips of the face plates 7 and 7 due to the wheel load and the strain of the root portion at the base portions of the face plates 7 and 7, that is, the opposing surfaces of the web plates 5 and 5. 9 is attached. Further, a humidity measuring meter 10 for measuring the water stopping member and the humidity in the vicinity thereof is attached to the back surface portion of the water stopping member 8.

  In addition, when a highly durable optical fiber sensor is used for the strain measurement sensor 9, a power source near the measurement point is not required, and an optical cable is placed inside the railing of the bridge and conducted from there, thereby continuing data remotely. Can be acquired.

  In addition, the free space A of the wall height column 3 is used to constantly monitor the deformation (displacement, misplacement, etc.) of the finger joint 4 itself and the road surface (wetting condition, water congestion, etc.) in the vicinity of the finger joint 4. A small surveillance camera 11 is installed.

  Further, in each of the gaps A of the wall height column 3, the displacement of the tips of the face plates 7, 7 measured by the strain measuring sensor 9, the strain of the base, and the humidity of the water stop member and the vicinity thereof are totaled. Measurement Box12 is installed.

  With such a configuration, the soundness of the finger joint 4 and the bridge body can be evaluated. In addition, by monitoring the deformation of the finger joint 4 itself and the road surface in the vicinity of the finger joint 4 (such as the road surface condition and the road surface stagnation condition) by the monitoring camera 11, the soundness of the finger joint 4 and the bridge body can be improved. Can be evaluated.

  Further, by monitoring the humidity of the water-stopping member 8 and its surroundings by using the humidity meter 11, the degree of wetness of the water-stopping member 8 and its surroundings is discriminated to evaluate the soundness of the bridge end girders against corrosion. be able to.

  Based on the results of these evaluations, the degree of damage and life of the finger joint 4, bridge body (road deck and bridge girder) and water-stopping member are estimated, and maintenance, replacement, and replacement are performed at an appropriate time. be able to.

  The expansion joint system for a bridge according to the present invention is not limited to the finger joint described with reference to FIGS. 1 to 4, and for example, generally used finger joints as illustrated in FIGS. 5 (a) and 5 (b). Needless to say, this can also be implemented.

  Incidentally, the finger joints shown in FIGS. 5 (a) and 5 (b) will be briefly described. A plurality of rib plates 13 and anchor bolts 14 instead of the anchor plates are installed on the back surfaces of the web plates 5 and 5.

  A plurality of anchor bars 15 are installed on the lower surface side of the face plate 7, and a base plate 16 is installed at the lower end of the web plates 5, 5. The rib plate 13 is disposed between the face plate 7 and the base plate 16 at a right angle to the web plate 5, the base plate 16, and the face plate 7 with an interval in a direction perpendicular to the bridge axis.

  The anchor bolts 14 are arranged with a constant length in the direction of the bridge axis at intervals across the entire back side of the web plate 5. The anchor bars are installed obliquely downward in the bridge axis direction at intervals in the direction perpendicular to the bridge axis.

  Moreover, each member installed in this way is integrally assembled by welding or the like.

  Other configurations such as the installation position of the strain measurement sensor and the monitoring camera and the monitoring method using the strain measurement sensor and the monitoring camera are substantially the same as those in the embodiment described with reference to FIGS.

  The present invention monitors the deformation (displacement, strain, etc.) of the expansion joint installed on the floor slab part of the road bridge with a strain measurement sensor or a monitoring camera, so that the expansion joint and the bridge body (floor part by the traffic load) And the bridge girder supporting the slab) can be evaluated, and maintenance and replacement of the bridge body and expansion joint can be performed at an appropriate time, and the bridge body can be replaced.

DESCRIPTION OF SYMBOLS 1 Bridge girder 2 Road deck 3 Wall height 4 Finger joint 5 Web plate 6 Anchor plate 7 Fay spray 8 Water stop member 9 Strain measuring sensor
10 Humidity meter
11 Surveillance camera
12 Measuring Box
13 Rib plate
14 Anchor bolt
15 Anchor bar
16 Base plate

Claims (5)

  In the expansion joint system for a bridge that evaluates the soundness of the expansion joint and the bridge body from the deformation of the expansion joint installed in the gap section provided in the bridge axis direction with a gap in the bridge slab portion, the gap section A pair of face plates constituting a finger joint flush with the road surface of the floor slab part, and a strain measurement sensor for measuring displacement and strain due to the wheel load of the face plate, and the displacement of the end of the face plate by the strain measurement sensor An expansion joint system for a bridge, characterized in that the integrity of the finger joint and the bridge body can be evaluated by monitoring the strain at the base of the face plate.   2. The expansion joint system for a bridge according to claim 1, further comprising a monitoring camera for monitoring the face plate and a road surface in the vicinity of the face plate, and monitoring the road surface in the vicinity of the face plate and the face plate by the monitoring camera. In addition, the bridge is configured to be able to evaluate the soundness of the finger joint and the bridge body by monitoring the displacement of the face plate tip and the strain of the face plate base by the strain measuring sensor. Expansion joint system.   The expansion joint device for bridges according to claim 1 or 2, wherein humidity measurement is performed to measure the water stop member and the humidity in the vicinity of the water stop member on the back side of the water stop member attached to the underside of the face plate so as to block the gap portion. An expansion joint system for a bridge comprising a sensor and configured to be able to evaluate the soundness of the bridge body from the water stop member and the wetness in the vicinity thereof.   The expansion joint device for a bridge according to any one of claims 1 to 3, wherein the face is provided in a play space provided in a wall height column laid on a side portion of the floor slab portion with a gap in a bridge axis direction. An expansion joint system for bridges, comprising a measurement box for calculating the wheel load acting on the plate and counting the displacement at the tip of the face plate and the strain at the base.   5. The expansion joint system for bridges according to claim 4, wherein the monitoring data is wirelessly transmitted from a measurement box having a data communication function, and the data is stored in an observation personal computer or an external cloud data center. An expansion joint system for bridges that enables quick evaluation of the soundness of bridge bodies and expansion devices by processing.

Images