JP5090292B2 - Reinforcement structure and reinforcement method for box-shaped diagonal members of lower steel truss bridge - Google Patents

Description

本発明は、下路鋼トラス橋における箱形断面斜材の腐食部の補強構造と補強方法に関する。   The present invention relates to a reinforcing structure and a reinforcing method for a corroded portion of a box-shaped diagonal member in a lower steel truss bridge.

図１５に示すように、下路鋼トラス橋１０は、二本の交差する斜材１１，１１０がコンクリート床版８１を貫通して下弦材（図示せず）と連結されている。前記斜材１１，１１０は、圧縮斜材である箱形断面斜材１１と引張斜材であるＨ形断面斜材１１０とからなる。前記箱形断面斜材１１は、四角形の断面形状を有し、内部が中空の角柱状のものであって、工場での製造時に密閉されて内面の腐食が防止されると共に、外面については塗装などによって腐食の防止が図られている。   As shown in FIG. 15, in the lower steel truss bridge 10, two intersecting diagonal members 11 and 110 penetrate a concrete floor slab 81 and are connected to a lower chord member (not shown). The diagonal members 11 and 110 include a box-shaped diagonal member 11 that is a compression diagonal member and an H-shaped diagonal member 110 that is a tensile diagonal member. The box-shaped oblique member 11 has a quadrangular cross-sectional shape, and has a hollow prismatic shape inside. The box-shaped oblique material 11 is sealed at the time of manufacture in a factory to prevent corrosion of the inner surface, and the outer surface is painted. Corrosion is prevented by such means.

しかし、下路鋼トラス橋１０は、経年変化による塗装の劣化や、コンクリート床板８１上に溜まる雨水や積雪地域で路面に散布される融雪剤等によって箱形断面斜材１１の外面に錆が発生して腐食が進行する。特に、図１６に示すように、箱形断面斜材１１のコンクリート床板８１との境界部外面に腐食部７１を生じ易い。前記箱形断面斜材１１の外面に生じた腐食部７１を放置すると、前記箱形断面斜材１１は腐食部７１の肉厚が減少して強度低下を生じる。そこで、前記腐食部７１を補強して強度低下を防ぐことが必要となる。   However, in the lower steel truss bridge 10, rust is generated on the outer surface of the box-shaped diagonal member 11 due to deterioration of the painting due to secular change, rain water collected on the concrete floor board 81, or a snow melting agent sprayed on the road surface in a snowy area. Corrosion proceeds. In particular, as shown in FIG. 16, the corroded portion 71 is likely to occur on the outer surface of the boundary portion between the box-shaped oblique member 11 and the concrete floor board 81. If the corroded portion 71 generated on the outer surface of the box-shaped oblique member 11 is left untreated, the thickness of the corroded portion 71 is reduced in the box-shaped oblique member 11 and the strength is lowered. Therefore, it is necessary to reinforce the corroded portion 71 to prevent strength reduction.

鋼橋の補強方法として、腐食によって減肉が発生し補強が必要となった場合、錆をグラインダで取り除き、この補強箇所に添接部材（補強板）を掛け渡して溶接すること、および高力ボルトにより添接部材を補強することが行われている。   As a steel bridge reinforcement method, when corrosion is necessary due to thinning due to corrosion, rust is removed with a grinder, and a welding member (reinforcement plate) is welded over this reinforcement, and high strength is achieved. Reinforcing the connecting member with a bolt is performed.

そこで、上記方法を下路鋼トラス橋の箱形断面斜材に適用する場合、全周に発生した錆を取り除いた後、添接部材を掛け渡し、溶接することも行われている。そして、溶接することにより箱形断面斜材の内面を密閉できるが、溶接による接合では母材である斜材が減耗により不陸であるため、均一な厚みを確保した接合が難しく、均一な強度で接合できない問題がある。また、ピンホールがあってもわからない問題がある。一方、高力ボルトによる補強方法では、密閉が困難で、水や酸素などの腐食因子が箱形断面斜材内に侵入しやすくなる。特に箱形断面斜材は工場での製造時に密閉されることにより内面の防錆が行われており、箱形断面斜材の内面については特に防錆処理が行われていないため、前記腐食因子が箱形断面斜材の内部に侵入することで、箱形断面斜材の内面から錆が発生し、箱形断面斜材が内部から腐食が進行する問題がある。   Therefore, when the above method is applied to the box-shaped oblique member of the lower steel truss bridge, after removing the rust generated on the entire circumference, the attachment member is passed over and welded. And by welding, the inner surface of the box-shaped diagonal material can be sealed, but since the diagonal material, which is the base material, is uneven due to wear, it is difficult to ensure a uniform thickness and uniform strength. There is a problem that can not be joined. In addition, there is a problem that is not known even if there is a pinhole. On the other hand, in the reinforcing method using high-strength bolts, sealing is difficult, and corrosion factors such as water and oxygen are likely to enter the box-shaped cross section diagonal member. In particular, the box-shaped cross-section diagonal is sealed at the time of manufacture in the factory to prevent rust on the inner surface, and the inner surface of the box-shaped cross-section diagonal is not subjected to rust prevention treatment. Intrusion into the inside of the box-shaped cross section diagonal material causes rust to be generated from the inner surface of the box-shaped cross section diagonal material, and there is a problem that the box-shaped cross section diagonal material proceeds from the inside.

なお、鋼製トラス構造物の補強については、以下の特許文献１に示すように、トラス構造物を構成している鋼管において、補強部位に半割り円筒部とフランジからなる補強部材を装着して補強部位を被覆するとともに、補強部材の内面を鋼管の外面に接着する構造が提案されている。しかし、この補強構造を下路鋼トラス橋の箱形断面斜材に適用した場合、補強に使用する材料が多いため、重量が増加することによって橋の全体構造へ悪影響を及ぼすことが懸念される。また、補強部材の内面と鋼管の外面間に空隙ができた場合、補強部材の内面と鋼管の外面に腐食が発生するおそれがあり、しかも補強部材で覆われた部分は、補強部材の存在によって補強部材の内面状態と鋼管の外面状態を外部から確認ができないため、補強部材の内面と鋼管の外面で知らない間に腐食が進行するおそれがある。   As for the reinforcement of the steel truss structure, as shown in Patent Document 1 below, in the steel pipe constituting the truss structure, a reinforcing member made up of a half-cylindrical cylindrical portion and a flange is attached to the reinforcing portion. A structure has been proposed in which the reinforcing portion is covered and the inner surface of the reinforcing member is bonded to the outer surface of the steel pipe. However, when this reinforcing structure is applied to the box-shaped cross-section diagonal member of a lower steel truss bridge, there are concerns that it may adversely affect the overall structure of the bridge due to the increase in weight because there are many materials used for reinforcement. . In addition, if there is a gap between the inner surface of the reinforcing member and the outer surface of the steel pipe, corrosion may occur on the inner surface of the reinforcing member and the outer surface of the steel pipe, and the portion covered with the reinforcing member is caused by the presence of the reinforcing member. Since the inner surface state of the reinforcing member and the outer surface state of the steel pipe cannot be confirmed from the outside, there is a possibility that corrosion proceeds without knowing the inner surface of the reinforcing member and the outer surface of the steel pipe.

さらに、鋼製トラス構造物の補強について、以下の特許文献２に示すように、補修箇所の表面に発生している錆をブラスト処理で除去した後、補正箇所に高周波アーク溶射を行って溶射材料による被覆層を形成し、補修箇所を原形状に復元する技術が提案されている。しかし、この技術を下路鋼トラス橋の箱形断面斜材に適用した場合、高周波アーク溶射の設備を現場まで搬入しなければならず、作業に手間取る問題がある。さらには、交通を妨げないようにするため、橋梁上の道路を開放しながら高周波アーク溶射を行うと、溶射時の一時的な部材耐力の低下による部材の破断や、振動による部材の欠損の可能性が高くなる問題がある。   Further, as shown in the following Patent Document 2, for reinforcing the steel truss structure, after removing rust generated on the surface of the repaired portion by blasting, high-frequency arc spraying is performed on the corrected portion to spray the material. A technique has been proposed in which a coating layer is formed by, and the repaired portion is restored to its original shape. However, when this technology is applied to the box-shaped cross section of the lower steel truss bridge, the equipment for high-frequency arc spraying has to be carried to the site, and there is a problem that it takes time and effort. Furthermore, in order not to obstruct traffic, if high-frequency arc spraying is performed while opening the road on the bridge, the member may be broken due to a temporary decrease in the member strength during spraying, or the member may be lost due to vibration. There is a problem that becomes high.

特開２００１−２０７５３２号公報JP 2001-207532 A 特開２００８−２４９５７号公報JP 2008-24957 A

本発明は、前記の点に鑑みなされたものであり、下路鋼トラス橋の箱形断面斜材の補強を容易に行うことができ、かつ箱形断面斜材の内部からの腐食を防止することができる補強構造と補強方法の提供を目的とする。   The present invention has been made in view of the above points, and can easily reinforce the box-shaped diagonal member of the lower steel truss bridge and prevent corrosion from the inside of the box-shaped diagonal member. An object of the present invention is to provide a reinforcing structure and a reinforcing method.

請求項１の発明は、下路鋼トラス橋の箱形断面斜材の外面に発生した腐食部を補強板で覆う補強構造において、前記腐食部を覆う補強板を締結部材で前記箱形断面斜材の外面に取り付け、前記補強板を取り付けた部分の前記箱形断面斜材内部に発泡ウレタンを充填して前記箱形断面斜材の内面と前記発泡ウレタンを密着させたことを特徴とする下路鋼トラス橋の箱形断面斜材の補強構造に係る。   The invention of claim 1 is a reinforcing structure in which a corroded portion generated on the outer surface of a box-shaped oblique member of a lower steel truss bridge is covered with a reinforcing plate, and the reinforcing plate covering the corroded portion is connected to the box-shaped oblique member with a fastening member. The lower surface is characterized in that it is attached to the outer surface of the material, and urethane foam is filled in the box-shaped cross-section diagonal member at the portion where the reinforcing plate is attached, so that the inner surface of the box-shaped cross-section diagonal material and the urethane foam are in close contact with each other. It relates to the reinforcing structure of box-shaped diagonal members of road steel truss bridges.

請求項２の発明は、請求項１において、前記補強板は前記箱形断面斜材の腐食部よりも上方部位と下方部位を高力ボルトとナットからなる締結部材で前記箱形断面斜材に固定し、前記上方部位と前記下方部位間を普通ボルトとナットからなる前記締結部材で前記箱形断面斜材に固定したことを特徴とする。   According to a second aspect of the present invention, in the first aspect, the reinforcing plate is formed on the box-shaped cross section diagonal member by a fastening member including a high-strength bolt and a nut at an upper portion and a lower portion of the corroded portion of the box-shaped cross section diagonal member. The upper portion and the lower portion are fixed to the box-shaped cross section diagonal member with the fastening member made of a normal bolt and a nut.

請求項３の発明は、下路鋼トラス橋の箱形断面斜材の外面に発生した腐食部を覆う補強板を前記箱形断面斜材の外面に取り付けて補強する方法において、前記箱形断面斜材の少なくとも一面は前記補強板を取り付けない補強板非取付面とし、前記補強板が取り付けられる部分の中央位置と対応する前記補強板非取付面の位置には補強板取付時作業用兼ウレタン充填用孔を形成すると共に、前記補強板非取付面の前記補強板取付時作業用兼ウレタン充填用孔の上方位置に上部ウレタン充填用孔を形成し、前記腐食部を覆う前記補強板を前記箱形断面斜材の外面に配置し、前記補強板取付時作業用兼ウレタン充填用孔から前記箱形断面斜材内に挿入した締結部材の一方の部材と前記補強板の外面側に配置した締結部材の他方の部材とで前記補強板を前記箱形断面斜材の外面に取り付け、前記補強板取付時作業用兼ウレタン充填用孔から前記箱形断面斜材内に発泡ウレタン注入ノズルを挿入し、前記発泡ウレタン注入ノズルより前記箱形断面斜材内に発泡ウレタンの液状原料を吐出して前記補強板取付時作業用兼ウレタン充填用孔の下側まで下側発泡ウレタンを充填し、前記補強板取付時作業用兼ウレタン充填用孔を覆う蓋部材を前記箱形断面斜材の外面に溶接で取り付け、前記上部ウレタン充填用孔から挿入した発泡ウレタン注入ノズルより発泡ウレタンの液状原料を吐出して前記下側発泡ウレタン上に前記上部ウレタン充填用孔の下側まで上側発泡ウレタンを充填し、その後、前記上部ウレタン充填用孔よりも上方の前記箱形断面斜材の内面に発泡ウレタンの液状原料を吐出して、該吐出した発泡ウレタンの液状原料を前記上部ウレタン充填用孔へ流下させると共に、前記上部ウレタン充填用孔に封止用ボルトを前記箱形断面斜材の外側から装着し、前記流下した発泡ウレタンの液状原料から形成された発泡ウレタンで前記箱形断面斜材内の前記封止用ボルトの周縁を封止することを特徴とする下路鋼トラス橋の箱形断面斜材の補強方法に係る。   According to a third aspect of the present invention, there is provided a method of reinforcing a reinforcing plate that covers a corroded portion generated on an outer surface of a box-shaped diagonal member of a lower steel truss bridge by attaching the reinforcing plate to the outer surface of the box-shaped diagonal member. At least one surface of the diagonal member is a reinforcing plate non-attaching surface to which the reinforcing plate is not attached, and the position of the reinforcing plate non-attaching surface corresponding to the center position of the portion to which the reinforcing plate is attached is a urethane for working when attaching the reinforcing plate. Forming a hole for filling, forming an upper urethane filling hole at a position above the hole for working and urethane filling when the reinforcing plate is attached to the non-reinforcing surface of the reinforcing plate, and forming the reinforcing plate covering the corroded portion Arranged on the outer surface of the box-shaped diagonal member, and arranged on the outer surface side of the reinforcing plate and one member of the fastening member inserted into the box-shaped diagonal member through the urethane filling hole for mounting the reinforcing plate The reinforcing plate with the other member of the fastening member Attached to the outer surface of the box-shaped cross-section diagonal material, insert a urethane foam injection nozzle into the box-shaped cross-section diagonal material from the hole for work and urethane filling when the reinforcing plate is installed, and the box-shaped cross section from the foam urethane injection nozzle Discharge the liquid material of urethane foam into the diagonal material and fill the lower foamed urethane to the lower side of the hole for work and urethane filling when the reinforcing plate is installed. A cover member for covering is attached to the outer surface of the box-shaped oblique member by welding, and a liquid raw material of foamed urethane is discharged from a foamed urethane injection nozzle inserted from the hole for filling the upper urethane, and the upper urethane is placed on the lower foamed urethane. The upper urethane foam is filled to the lower side of the filling hole, and then the liquid material of the urethane foam is discharged onto the inner surface of the box-shaped oblique member above the upper urethane filling hole, The liquid material of the foamed urethane that has flowed out is allowed to flow down into the upper urethane filling hole, and a sealing bolt is attached to the upper urethane filling hole from the outside of the box-shaped cross-section diagonal member, and the liquid urethane foam that has flowed down is liquidated. The present invention relates to a method for reinforcing a box-shaped cross-section diagonal member of a lower steel truss bridge, characterized by sealing a peripheral edge of the sealing bolt in the box-shaped cross-section diagonal member with urethane foam formed from a raw material.

請求項４の発明は、請求項３において、前記補強板は前記箱形断面斜材の腐食部よりも上方部位と下方部位を高力ボルトとナットからなる前記締結部材で前記箱形断面斜材に固定し、前記上方部位の高力ボルトと前記下方部位の高力ボルト間を普通ボルトとナットからなる前記締結部材で前記箱形断面斜材に固定することを特徴とする。   According to a fourth aspect of the present invention, in the third aspect of the present invention, the box-shaped cross-section diagonal member is the reinforcing member in the upper portion and the lower portion of the corroded portion of the box-shaped cross-section diagonal member with the fastening member made of high-strength bolts and nuts. The high-strength bolt in the upper part and the high-strength bolt in the lower part are fixed to the box-shaped oblique member with the fastening member composed of a normal bolt and a nut.

請求項５の発明は、請求項３または４において、前記下側発泡ウレタンの充填時に、前記締結部材が位置する前記箱形断面斜材の内面に前記発泡ウレタンの液状原料を吹き付けることを特徴とする。   The invention of claim 5 is characterized in that, in filling of the lower foamed urethane, the liquid material of the foamed urethane is sprayed on the inner surface of the box-shaped cross-section diagonal member in which the fastening member is located. To do.

工場での製造時に密閉された箱形断面斜材は、補強板を箱形断面斜材の外面に締結部材で取り付ける際に箱形断面斜材に形成される締結部材用孔等によって密閉が損なわれ、水分や酸素などの腐食因子が締結部材用孔等を介して外部から箱形断面斜材内に侵入することになる。しかし、本発明の補強構造によれば、補強板を取り付けた部分の箱形断面斜材の内部に発泡ウレタンを充填して箱形断面斜材の内面と発泡ウレタンを密着させているため、腐食因子が箱形断面斜材の内面に接触するのを発泡ウレタンによって阻止することができ、箱形断面斜材が腐食因子によって内部から腐食するのを防ぐことができる。さらに、箱形断面斜材内部に充填した発泡ウレタンによって箱形断面斜材の締結部材用孔等が封止されるため、その後に締結部材用孔等から腐食因子が箱形断面斜材内に侵入するのを防ぐことができ、箱形断面斜材が腐食因子によって内部から腐食するのを防止することができる。   The box-shaped diagonal member sealed at the time of manufacturing at the factory is damaged by the fastening member holes formed in the box-shaped diagonal member when the reinforcing plate is attached to the outer surface of the box-shaped diagonal member with the fastening member. As a result, corrosion factors such as moisture and oxygen enter the box-shaped oblique member from the outside through the holes for fastening members. However, according to the reinforcing structure of the present invention, the inside of the box-shaped diagonal member with the reinforcing plate attached is filled with urethane foam so that the inner surface of the box-shaped diagonal member and the urethane foam are in close contact with each other. It is possible to prevent the factor from coming into contact with the inner surface of the box-shaped oblique member by the urethane foam, and it is possible to prevent the box-shaped oblique member from being corroded from the inside by the corrosion factor. Furthermore, since the holes for the fastening members of the box-shaped diagonal member are sealed by the foamed urethane filled in the box-shaped diagonal member, the corrosion factor is then introduced into the box-shaped diagonal member from the fastener member hole. Intrusion can be prevented, and the box-shaped cross-section diagonal can be prevented from corroding from the inside by a corrosion factor.

また、本発明の補強構造において、補強板を箱形断面斜材の腐食部よりも上方部位と下方部位については高力ボルトとナットで前記箱形断面斜材に固定し、前記上方部位の高力ボルトと前記下方部位の高力ボルト間については普通ボルトとナットで箱形断面斜材に固定することにより、箱形断面斜材において腐食による強度低下の可能性が無い部分、すなわち腐食部より上方部位と下方部位については補強板を高力ボルトで強固に取り付けて高い補強効果を実現することができると共に、腐食によって強度が低下している可能性のある部分、すなわち前記上方部位と前記下方部位間については高力ボルトよりも締め付け力が弱い普通ボルトで補強板を取り付けることにより、ボルトの強い締め付け力で箱形断面斜材が局所的に強度低下するのを防ぐことができ、かつ、上下の高力ボルト間の部分で補強板が箱形断面斜材の外面から浮き上がるのを防いで、前記浮き上がり部分の補強板内面と箱形断面斜材の外面に腐食因子が侵入して腐食を生じるのを阻止することができる。   Further, in the reinforcing structure of the present invention, the reinforcing plate is fixed to the box-shaped diagonal member with high-strength bolts and nuts at the upper part and the lower part of the corroded portion of the box-shaped diagonal member, and the height of the upper part is increased. Between the force bolt and the high-strength bolt in the lower part, it is fixed to the box-shaped diagonal member with normal bolts and nuts, so that there is no possibility of strength reduction due to corrosion in the box-shaped diagonal member, that is, from the corroded part. For the upper part and the lower part, the reinforcing plate can be firmly attached with high-strength bolts to achieve a high reinforcing effect, and the part whose strength may be reduced by corrosion, that is, the upper part and the lower part By attaching a reinforcing plate with normal bolts that have a lower tightening force than high-strength bolts between the parts, the box-shaped cross section diagonally decreases in strength locally due to the strong tightening force of the bolts. This prevents the reinforcing plate from floating from the outer surface of the box-shaped diagonal member between the upper and lower high-strength bolts and corrodes the inner surface of the reinforcing plate at the raised portion and the outer surface of the box-shaped diagonal member. It is possible to prevent factors from entering and causing corrosion.

一方、本発明の補強方法によれば、箱形断面斜材の補強板非取付面に形成した補強板取付時作業用兼ウレタン充填用孔を利用して締結部材による補強板の取付作業を容易に行うことができる。また、補強板取付時作業用兼ウレタン充填用孔から箱形断面斜材内に挿入した発泡ウレタン注入ノズルから発泡ウレタンの液状原料を吐出して補強板取付時作業用兼ウレタン充填用孔の下側まで下側発泡ウレタンを充填し、補強板取付時作業用兼ウレタン充填用孔を覆う蓋部材を箱形断面斜材の外面に溶接で取り付けた後に、上部ウレタン充填用孔から挿入した発泡ウレタン注入ノズルより発泡ウレタンの液状原料を吐出して、下側発泡ウレタン上に上部ウレタン充填用孔の下側まで上側発泡ウレタンを充填しているため、補強板取付時作業用兼ウレタン充填用孔から発泡ウレタンを漏出させることなく発泡ウレタンを箱形断面斜材内に充填することができると共に、補強板取付時作業用兼ウレタン充填用孔を発泡ウレタンと蓋部材で封止するため、補強板取付時作業用兼ウレタン充填用孔から腐食因子が断面箱形斜材内に侵入するのを防止することができる。さらに、その後に、上部ウレタン充填用孔よりも上方の箱形断面斜材の内面に発泡ウレタンの液状原料を吐出して該吐出した発泡ウレタンの液状原料を上部ウレタン充填用孔へ流下させると共に、上部ウレタン充填用孔に封止用ボルトを箱形断面斜材の外側から装着し、前記流下した発泡ウレタンの液状原料から形成した発泡ウレタンで箱形断面斜材内の前記封止用ボルトの周縁を封止しているため、上部ウレタン充填用孔から腐食因子が箱形断面斜材内に侵入するのを阻止することができる。また、前記補強板取付時作業用兼ウレタン充填用孔を覆う蓋部材を溶接する場合では、溶接箇所で完全に密閉されないことがあっても、発泡ウレタンを充填することで、封止することができる。   On the other hand, according to the reinforcing method of the present invention, it is easy to attach the reinforcing plate with the fastening member using the reinforcing plate mounting hole and urethane filling hole formed on the reinforcing plate non-mounting surface of the box-shaped oblique member. Can be done. In addition, the liquid material of urethane foam is discharged from the urethane foam injection nozzle inserted into the box-shaped oblique member from the hole for work and urethane filling when the reinforcing plate is installed, and below the hole for work and urethane filling when the reinforcing plate is installed. The foamed urethane inserted into the upper urethane filling hole after filling the bottom foamed urethane to the side and welding the cover member covering the urethane filling hole for mounting the reinforcing plate to the outer surface of the box-shaped cross section diagonal material Since the liquid material of urethane foam is discharged from the injection nozzle and the upper foamed urethane is filled on the lower foamed urethane to the lower side of the upper urethane filling hole, from the hole for work and urethane filling when installing the reinforcing plate The foamed urethane can be filled into the box-shaped diagonal member without leaking the foamed urethane, and the work and urethane filling hole when sealing the reinforcing plate is sealed with the foamed urethane and the lid member. Therefore, the corrosion factor from the reinforcing plate mounted at the working and urethane filling hole can be prevented from entering the cross-section box-shaped diagonal in material. Furthermore, after that, the liquid raw material of urethane foam is discharged onto the inner surface of the box-shaped oblique member above the upper urethane filling hole, and the discharged liquid material of foamed urethane flows down to the upper urethane filling hole, A sealing bolt is attached to the upper urethane filling hole from the outside of the box-shaped diagonal member, and the periphery of the sealing bolt in the box-shaped diagonal member is made of foamed urethane formed from the liquid material of the foamed urethane that has flowed down. Therefore, it is possible to prevent a corrosion factor from entering the box-shaped cross section through the upper urethane filling hole. In addition, when welding the lid member that covers the hole for working and urethane filling when the reinforcing plate is attached, even if the lid member is not completely sealed at the welded portion, it can be sealed by filling with urethane foam. it can.

このように、本発明の補強方法によれば、アーク溶射等の面倒な作業が不要であるため、橋上の道路を閉鎖することなく容易に腐食部を補強することが可能であり、しかも、箱形断面斜材の内面には発泡ウレタンが密着しているため、箱形断面斜材の内面に対する腐食防止効果を得ることができ、箱形断面斜材の内部からの腐食を防止することができる。   As described above, according to the reinforcing method of the present invention, since troublesome work such as arc spraying is unnecessary, it is possible to easily reinforce the corroded portion without closing the road on the bridge. Because the foamed urethane is in close contact with the inner surface of the diagonal section, the anti-corrosion effect on the inner surface of the box section diagonal can be obtained, and corrosion from inside the box section diagonal can be prevented. .

さらに、本発明の補強方法における補強板の取付に際し、補強板を箱形断面斜材の腐食部よりも上方部位と下方部位については高力ボルトとナットで前記箱形断面斜材に固定し、前記上方部位の高力ボルトと前記下方部位の高力ボルト間については補強板を普通ボルトとナットで箱形断面斜材に固定することにより、箱形断面斜材において腐食による強度低下の可能性が無い部分については補強板を高力ボルトで強固に取り付けて高い補強効果を実現することができると共に、上下の高力ボルト間において腐食による強度低下の可能性がある箱形断面斜材の部分については、高力ボルトよりも締め付け力の弱い普通ボルトで補強板を固定することにより、ボルトの締め付け力で箱形断面斜材が局所的に強度低下するのを防ぐことができ、かつ、上下の高力ボルト間の部分で補強板が箱形断面斜材の外面から浮き上がるのを防いで、浮き上がり部分の補強板内面と箱形断面斜材の外面に腐食因子が侵入して腐食を生じるのを阻止することができる。   Furthermore, when attaching the reinforcing plate in the reinforcing method of the present invention, the reinforcing plate is fixed to the box-shaped oblique member with a high-strength bolt and nut for the upper portion and the lower portion of the corroded portion of the box-shaped oblique member, Between the high-strength bolts in the upper part and the high-strength bolts in the lower part, by fixing the reinforcing plate to the box-shaped section diagonal with normal bolts and nuts, there is a possibility of strength reduction due to corrosion in the box-shaped section diagonal The part with no cross section is a box-shaped diagonal member that can be firmly attached with high-strength bolts to achieve a high reinforcing effect and that there is a possibility of strength reduction due to corrosion between the upper and lower high-strength bolts. With regard to, by fixing the reinforcing plate with ordinary bolts with a lower tightening force than high strength bolts, it is possible to prevent the box-shaped cross section diagonal material from locally lowering the strength due to the tightening force of the bolts, and Prevents the reinforcing plate from floating from the outer surface of the box-shaped diagonal member between the upper and lower high-strength bolts. Corrosion factors invade the inner surface of the reinforcing plate at the raised portion and the outer surface of the box-shaped diagonal member to cause corrosion. Can be prevented.

さらに、本発明の補強方法において、下側発泡ウレタンの充填時に、締結部材が位置する箱形断面斜材の内面に発泡ウレタンの液状原料を吹き付けることにより、前記締結部材が位置する箱形断面斜材の内面上で発泡ウレタンを直接発泡させることができ、発泡ウレタンの発泡時に生じる接着性によって発泡ウレタンを、締結部材が位置する箱形断面斜材内面に確実に接着して密着させることができるため、発泡ウレタンにより締結部材用孔等の封止性を確実にして締結部材が位置する箱形断面斜材内面の腐食防止効果を高めることができる。   Furthermore, in the reinforcing method of the present invention, when filling the lower foamed urethane, the foamed urethane liquid material is sprayed onto the inner surface of the box-shaped oblique member on which the fastening member is located, so that the box-shaped oblique member on which the fastening member is located. The urethane foam can be directly foamed on the inner surface of the material, and the urethane foam can be securely adhered and adhered to the inner surface of the box-shaped cross section diagonal member where the fastening member is located by the adhesiveness generated when foaming the foamed urethane. Therefore, it is possible to enhance the corrosion prevention effect on the inner surface of the box-shaped oblique member where the fastening member is located by ensuring the sealing performance of the fastening member hole or the like by urethane foam.

以下に、図面を用いて本発明の実施例を説明する。図１は本発明の補強構造で補強された下路鋼トラス橋の箱形断面斜材の一部を示す斜視図、図２は図１の２−２断面図、図３は図１の３−３断面図、図４は図１の４−４断面図、図５は図１の５−５断面図である。一方、図６は本発明の補強方法の一実施例において箱形断面斜材周囲のコンクリート床版を掘り起こした状態を示す斜視図、図７は同実施例において箱形断面斜材に補強板取付時作業用兼ウレタン充填用孔等を形成した状態を示す斜視図、図８は同実施例において箱形断面斜材に補強板を固定した状態を示す斜視図、図９は図８の９−９断面図、図１０は同実施例において発泡ウレタンの液状原料吹き付けを示す断面図、図１１は同実施例において下側発泡ウレタンの充填を示す断面図、図１２は同実施例において下側発泡ウレタンの充填後を示す断面図、図１３は同実施例において上側発泡ウレタンの充填を示す断面図、図１４は同実施例において上部ウレタン充填用孔よりも上方の箱形断面斜材の内面に発泡ウレタンの液状原料を吐出する際を示す断面図である。   Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing a part of a box-shaped diagonal member of a lower steel truss bridge reinforced with the reinforcing structure of the present invention, FIG. 2 is a cross-sectional view taken along line 2-2 in FIG. 1, and FIG. 3 is a sectional view taken along line 4-4 in FIG. 1, and FIG. 5 is a sectional view taken along line 5-5 in FIG. On the other hand, FIG. 6 is a perspective view showing a state in which the concrete floor slab around the box-shaped diagonal member is dug up in one embodiment of the reinforcing method of the present invention, and FIG. FIG. 8 is a perspective view showing a state in which a reinforcing plate is fixed to a box-shaped oblique member in the same embodiment, and FIG. 9 is a cross-sectional view showing the foamed urethane liquid material spraying in the same embodiment, FIG. 11 is a cross-sectional view showing the filling of the lower foamed urethane in the same embodiment, FIG. 12 is the lower foam in the same embodiment FIG. 13 is a sectional view showing the filling of the upper foamed urethane in the same embodiment, and FIG. 14 is an inner surface of the box-shaped oblique member above the upper urethane filling hole in the same embodiment. Discharge liquid material of urethane foam When is a sectional view showing a.

図１〜図５に示す下路鋼トラス橋の箱形断面斜材１１の補強構造は、図１５及び図１６に示した下路綱トラス橋１０における箱形断面斜材１１において、コンクリート床板８１との境界に発生した腐食部７１（図１６及び図６に示す）を補強板３１で補強する構造である。   The reinforcing structure of the box-shaped diagonal member 11 of the lower steel truss bridge shown in FIGS. 1 to 5 is the same as that of the box-shaped diagonal member 11 in the lower rope truss bridge 10 shown in FIGS. 15 and 16. The corroded portion 71 (shown in FIGS. 16 and 6) generated at the boundary with the reinforcing plate 31 is reinforced.

前記箱形断面斜材１１は、四角形の断面形状を有し、内部が中空の角柱状のものであり、前記コンクリート床板８１を貫通した下方部分では、対向する一組の側面がＶ字形状に閉じて他の組の側面とによって断面略Ｈ字形になっている。また、本実施例において、前記箱形断面斜材１１は、前記下路鋼トラス橋１０における下弦材（図示せず）との連結が道路側の側面と欄干側の側面のみで行われており、下弦材と連結されている側面に応力が主に働くため、道路側の側面と欄干側の側面を補強板取付面１２，１３とし、前記補強板取付面１２，１３における腐食部を覆って補強板３１が締結部材４１で取り付けられている。前記箱形断面斜材１１において、補強板取付面１２，１３以外の他の面は、補強板を取り付けない補強板非取付面１４，１５となっている。本実施例において前記補強板取付面１２，１３に補強板３１を取り付ける締結部材４１は後述のように高力ボルト４３とナット４４、及び普通ボルト４５とナット４６で構成されている。なお、図２及び図５等における符号１４ａ，１５ａは、前記補強板非取付面１４，１５の下方位置においてＶ字状に先細となっている面である。   The box-shaped cross-section diagonal member 11 has a rectangular cross-sectional shape and has a hollow prismatic shape inside, and a pair of opposing side surfaces are V-shaped in the lower part that penetrates the concrete floor board 81. It is closed and has a substantially H-shaped cross section with the other set of side surfaces. In the present embodiment, the box-shaped cross section diagonal member 11 is connected to the lower chord member (not shown) in the lower steel truss bridge 10 only on the side surface on the road side and the side surface on the balustrade side. Since the stress mainly acts on the side surface connected to the lower chord material, the side surface on the road side and the side surface on the balustrade side are used as the reinforcing plate mounting surfaces 12 and 13 to cover the corroded portions on the reinforcing plate mounting surfaces 12 and 13. A reinforcing plate 31 is attached by a fastening member 41. In the box-shaped cross-section diagonal member 11, the other surfaces other than the reinforcing plate attaching surfaces 12 and 13 are reinforcing plate non-attaching surfaces 14 and 15 to which no reinforcing plate is attached. In this embodiment, the fastening member 41 for attaching the reinforcing plate 31 to the reinforcing plate attaching surfaces 12 and 13 includes a high-strength bolt 43 and a nut 44, and a normal bolt 45 and a nut 46, as will be described later. Reference numerals 14a and 15a in FIGS. 2 and 5 and the like are surfaces tapered in a V shape at positions below the reinforcing plate non-mounting surfaces 14 and 15, respectively.

補強を行う際は、前記補強板を取り付ける付近のコンクリート床板８１を掘削して、前記箱形断面斜材１１を補強する作業場所を確保する。前記箱形断面斜材１１の外面の腐食部７１（図６に示す）は、前記補強板３１の取付に先立って、腐食による錆等をブラスト処理等によって落とし、錆止め塗料の塗布等の錆止め処理が行われる。前記錆止め処理された腐食部を覆って前記補強板取付面１２，１３に取り付けられる補強板３１は、前記腐食部７１を覆うことができ、かつ前記腐食部７１よりも大の上下寸法、例えば短辺３４０ｍｍ×長辺６５０ｍｍの平行四辺形の綱板からなる。前記補強板３１は、前記腐食部７１の上方位置と下方位置が高力ボルト４３とナット４４で前記補強板取付面１２，１３に固定され、上下の高力ボルト４３間の位置が普通ボルト４５とナット４６で前記補強板取付面１２，１３に固定される。図３の符号３３は締結部材用孔として前記補強板３１に形成された高力ボルト用ボルト孔、符号１７は締結部材用孔として前記箱形断面斜材１１の補強板取付面１２，１３に形成された高力ボルト用ボルト孔、図４の符号３４は締結部材用孔として前記補強板３１に形成された普通ボルト用ボルト孔、符号１８は締結部材用孔として前記箱形断面斜材１１の補強板取付面１２，１３に形成された普通ボルト用ボルト孔である。本実施例では、前記箱形断面斜材１１における腐食部の上下に位置する高力ボルト用ボルト孔１７は、上下各２行×３列で形成され、一方、上下の前記高力ボルト用ボルト孔１７間に位置する普通ボルト用ボルト孔１８は、３行×２列で形成されており、前記箱形断面斜材１１の高力ボルト用ボルト孔１７及び普通ボルト用ボルト孔１８に合わせて、前記補強板３１には締結部材用孔として高力ボルト用ボルト孔３３及び普通ボルト用ボルト孔３４が形成されている。   When reinforcement is performed, a concrete floor board 81 in the vicinity of which the reinforcement plate is attached is excavated to secure a work place for reinforcing the box-shaped oblique member 11. The corroded portion 71 (shown in FIG. 6) on the outer surface of the box-shaped cross-section diagonal member 11 removes rust or the like due to corrosion by blasting or the like prior to mounting of the reinforcing plate 31, and rust prevention treatment such as application of a rust-preventing paint. Is done. The reinforcing plate 31 that covers the corroded corrosion-treated portion and is attached to the reinforcing plate mounting surfaces 12 and 13 can cover the corroded portion 71 and has a larger vertical dimension than the corroded portion 71, for example, a short dimension. It consists of a parallelogram steel plate with sides 340 mm × long sides 650 mm. The reinforcing plate 31 is fixed to the reinforcing plate mounting surfaces 12 and 13 with high strength bolts 43 and nuts 44 at the upper and lower positions of the corroded portion 71, and the position between the upper and lower high strength bolts 43 is a normal bolt 45. And the nut 46 are fixed to the reinforcing plate mounting surfaces 12 and 13. 3 is a bolt hole for a high-strength bolt formed in the reinforcing plate 31 as a fastening member hole. Reference numeral 17 is a reinforcing plate mounting surface 12, 13 of the box-shaped cross section diagonal member 11 as a fastening member hole. The bolt holes for high strength bolts formed, the reference numeral 34 in FIG. 4 is a bolt hole for ordinary bolts formed in the reinforcing plate 31 as a fastening member hole, and the reference numeral 18 is the box-shaped cross section diagonal 11 as a fastening member hole. These are bolt holes for ordinary bolts formed on the reinforcing plate mounting surfaces 12 and 13. In the present embodiment, the bolt holes 17 for high strength bolts located above and below the corroded portion of the box-shaped oblique member 11 are formed in two rows and three columns on the upper and lower sides, while the upper and lower bolts for the high strength bolts are formed. The bolt holes 18 for ordinary bolts located between the holes 17 are formed in 3 rows × 2 columns, and are matched to the bolt holes 17 for high-strength bolts and the bolt holes 18 for ordinary bolts of the box-shaped cross section diagonal member 11. The reinforcing plate 31 is formed with bolt holes 33 for high strength bolts and bolt holes 34 for ordinary bolts as holes for fastening members.

前記補強板３１を前記箱形断面斜材１１の補強板取付面１２，１３へ取り付ける作業は、前記箱形断面斜材１１において前記補強板非取付面１４，１５のうち一つの補強板非取付面１５に形成された補強板取付時作業用兼ウレタン充填用孔１９から、前記箱形断面斜材１１内に挿入した締結部材４１の一方の部材（本実施例ではボルトあるいはナット）と、前記補強板３１の外面側に配置した締結部材の他方の部材との結合によって行われる。前記補強板取付時作業用兼ウレタン充填用孔１９は、前記箱形断面斜材１１において補強板３１が取り付けられる部分の中央位置と対応する前記補強板非取付面１５の位置に、作業者の手が挿入可能な大きさ、例えば直径１５０ｍｍで形成されている。   The operation of attaching the reinforcing plate 31 to the reinforcing plate mounting surfaces 12 and 13 of the box-shaped cross-section diagonal member 11 is that the reinforcing plate non-attaching surfaces 14 and 15 of the box-shaped cross-section diagonal member 11 are not attached. One member (bolt or nut in this embodiment) of the fastening member 41 inserted into the box-shaped cross-section diagonal member 11 from the hole 19 for work and urethane filling at the time of mounting the reinforcing plate formed on the surface 15; This is performed by coupling with the other member of the fastening member disposed on the outer surface side of the reinforcing plate 31. The reinforcing plate mounting work / urethane filling hole 19 is provided at the position of the reinforcing plate non-mounting surface 15 corresponding to the center position of the portion where the reinforcing plate 31 is mounted in the box-shaped cross section diagonal member 11. It is formed in a size that allows a hand to be inserted, for example, 150 mm in diameter.

前記補強板３１を取り付けた部分の前記箱形断面斜材１１の内部には、発泡ウレタン５１が充填されて前記箱形断面斜材１１の内面に前記発泡ウレタン５１が密着し、前記箱形断面斜材１１内に存在する補強板取付用締結部材４１の周囲が発泡ウレタン５１で封止されると共に、前記発泡ウレタン５１と密着している前記箱形断面斜材１１の内面が腐食因子と接触するのが防止されている。前記発泡ウレタン５１は、公知の発泡ポリウレタンの液状原料から発泡したものであり、独立気泡を主体とする硬質ポリウレタンフォームからなる。前記発泡ポリウレタンの液状原料は、主にポリオール成分からなり、整泡剤、その他の添加剤を加えたＡ液とポリイソシアネート成分からなるＢ液の二液を混合したものである。   Inside the box-shaped oblique member 11 to which the reinforcing plate 31 is attached is filled with foamed urethane 51 so that the foamed urethane 51 is in close contact with the inner surface of the box-shaped oblique member 11, and the box-shaped cross-section. The periphery of the reinforcing plate mounting fastening member 41 existing in the diagonal member 11 is sealed with foamed urethane 51, and the inner surface of the box-shaped diagonal member 11 in close contact with the urethane foam 51 is in contact with a corrosion factor. Is prevented. The urethane foam 51 is foamed from a known liquid material of polyurethane foam, and is made of a rigid polyurethane foam mainly composed of closed cells. The liquid raw material of the polyurethane foam is mainly composed of a polyol component, and is a mixture of two liquids, liquid A and a liquid B containing a polyisocyanate component, to which a foam stabilizer and other additives are added.

前記発泡ウレタン５１は、吹きつけ発泡ウレタン層５２と下側発泡ウレタン５３と上側発泡ウレタン５５と最上部発泡ウレタン５７の積層体からなる。前記発泡ウレタン５１の充填は、後述する補強方法の説明において詳述に述べることとし、ここでは簡単に示す。   The urethane foam 51 is composed of a laminate of a blown urethane foam layer 52, a lower foamed urethane 53, an upper foamed urethane 55, and an uppermost foamed urethane 57. The filling of the urethane foam 51 will be described in detail in the description of the reinforcing method to be described later, and is simply shown here.

前記吹きつけ発泡ウレタン層５２は、図１０に示すように、前記箱形断面斜材１１の補強板非取付面１５に形成された補強板取付時作業用兼ウレタン充填用孔１９から挿入した発泡ウレタン注入ノズルＮ１より、前記締結部材４１が位置する箱形断面斜材１１の内面に発泡ウレタンの液状原料Ｐを吹き付ける、いわゆる現場施工可能な吹きつけタイプの硬質ウレタン施工を行うことにより形成されたものであり、前記箱形断面斜材１１の内面に締結部材４１を覆って形成されている。前記吹きつけ発泡ウレタン層５２は、発泡ウレタンの発泡時に生じる接着性によって締結部材４１が位置する箱形断面斜材１１の内面に確実に接着して密着するため、締結部材用孔等の封止性を確実にして締結部材４１が位置する箱形断面斜材１１内面の腐食防止効果を高めることができる。   As shown in FIG. 10, the blown foamed urethane layer 52 is a foam inserted through a reinforcing plate mounting work / urethane filling hole 19 formed on the reinforcing plate non-attaching surface 15 of the box-shaped cross section diagonal member 11. It was formed by performing a so-called on-site construction-type hard urethane construction, in which a foamed urethane liquid material P is sprayed from the urethane injection nozzle N1 to the inner surface of the box-shaped oblique member 11 where the fastening member 41 is located. The box-shaped cross-section diagonal member 11 is formed so as to cover the fastening member 41. The blown urethane foam layer 52 is securely adhered and adhered to the inner surface of the box-shaped oblique member 11 on which the fastening member 41 is located due to the adhesiveness generated when foaming urethane foams. Therefore, the corrosion prevention effect of the inner surface of the box-shaped oblique member 11 where the fastening member 41 is located can be enhanced.

前記下側発泡ウレタン５３の充填は、図１１に示すように、前記箱形断面斜材１１の補強板非取付面１５に形成された補強板取付時作業用兼ウレタン充填用孔１９から挿入した発泡ウレタン注入ノズルＮ１より発泡ウレタンの液状原料Ｐを吐出して、前記補強板取付時作業用兼ウレタン充填用孔１９の下側まで前記下側発泡ウレタン５３を充填することにより行われる。前記下側発泡ウレタンの充填後、図１２に示すように、前記補強板取付時作業用兼ウレタン充填用孔１９を覆う蓋部材６１を補強板非取付面１５の外面に溶着することにより、前記補強板取付時作業用兼ウレタン充填用孔１９は塞がれる。   As shown in FIG. 11, the filling of the lower foamed urethane 53 was inserted through the reinforcing plate mounting work / urethane filling hole 19 formed on the reinforcing plate non-mounting surface 15 of the box-shaped cross section diagonal member 11. This is performed by discharging a foamed urethane liquid raw material P from the foamed urethane injection nozzle N1 and filling the lower foamed urethane 53 to the lower side of the work and urethane filling hole 19 when the reinforcing plate is attached. After filling the lower foamed urethane, as shown in FIG. 12, the lid member 61 covering the reinforcing plate mounting work / urethane filling hole 19 is welded to the outer surface of the reinforcing plate non-mounting surface 15, The work and urethane filling hole 19 is closed when the reinforcing plate is attached.

一方、前記上側発泡ウレタン５５の充填は、図１３に示すように、前記補強板非取付面１５における前記補強板取付時作業用兼ウレタン充填用孔１９の上方に形成されている上部ウレタン充填用孔２１から挿入した発泡ウレタン注入ノズルＮ２より発泡ウレタンの液状原料Ｐを吐出して、前記下側発泡ウレタン５３上に前記上部ウレタン充填用孔２１の下側まで前記上側発泡ウレタン５５を充填することにより行われる。前記上部ウレタン充填用孔２１は、発泡ウレタン注入ノズルＮ２が挿入可能な大きさとされ、本実施例では直径２７ｍｍのタップ孔で形成されている。   On the other hand, as shown in FIG. 13, the filling of the upper foamed urethane 55 is for filling the upper urethane formed above the reinforcing plate mounting work / urethane filling hole 19 in the reinforcing plate non-mounting surface 15. The liquid material P of urethane foam is discharged from the urethane foam injection nozzle N2 inserted from the hole 21 to fill the upper foamed urethane 55 on the lower foamed urethane 53 to the lower side of the upper urethane filling hole 21. Is done. The upper urethane filling hole 21 has such a size that the urethane foam injection nozzle N2 can be inserted, and is formed by a tap hole having a diameter of 27 mm in this embodiment.

前記最上部発泡ウレタン５７の充填は、前記上側発泡ウレタン充填後、図１４に示すように、Ｕ字状に屈曲した発泡ウレタン注入ノズルＮ３を前記上部ウレタン充填用孔２１から前記箱形断面斜材１１内に挿入して、前記上部ウレタン充填用孔２１よりも上方の前記箱形断面斜材１１の内面１１ａに発泡ウレタンの液状原料Ｐを吐出し、該吐出した発泡ウレタンの液状原料Ｐを前記上部ウレタン充填用孔２１へ流下させると共に、前記上部ウレタン充填用孔２１に封止用ボルト６３（図１及び図２に示す）を前記箱形断面斜材１１の外側から装着し、前記流下した発泡ウレタンの液状原料から前記最上部発泡ウレタン５７を発泡することにより行われる。その際、前記箱形断面斜材１１内の前記封止用ボルト６３の周縁は前記最上部発泡ウレタン５７によって封止される。   As shown in FIG. 14, after filling the uppermost foamed urethane 57, the foamed urethane injection nozzle N3 bent in a U shape is inserted into the box-shaped cross section oblique material from the upper urethane filling hole 21 as shown in FIG. 11, the foamed urethane liquid material P is discharged onto the inner surface 11a of the box-shaped oblique member 11 above the upper urethane filling hole 21, and the discharged urethane foam liquid material P is While flowing down to the upper urethane filling hole 21, a sealing bolt 63 (shown in FIGS. 1 and 2) was attached to the upper urethane filling hole 21 from the outside of the box-shaped oblique member 11 and flowed down. It is carried out by foaming the uppermost foamed urethane 57 from a liquid material of foamed urethane. At that time, the periphery of the sealing bolt 63 in the box-shaped cross section diagonal 11 is sealed by the uppermost urethane foam 57.

次に、下路鋼トラス橋の箱形断面斜材１１を前記補強構造で補強する方法の実施例について図６〜図１４を用いて説明する。本実施例の補強方法では、図６に示すように、前記箱形断面斜材１１は、下弦材（図示せず）と連結されている道路側の側面と欄干側の側面を補強板取付面１２，１３とし、前記補強板取付面１２，１３における腐食部７１を図１に示した前記補強板３１で以下のように覆って補強する。前記箱形断面斜材１１において、補強板取付面１２，１３以外の他の面は、補強板を取り付けない補強板非取付面１４，１５となっている。   Next, an embodiment of a method for reinforcing the box-shaped oblique member 11 of the lower steel truss bridge with the reinforcing structure will be described with reference to FIGS. In the reinforcing method of the present embodiment, as shown in FIG. 6, the box-shaped cross section diagonal member 11 has a reinforcing plate mounting surface on the road side surface and the balustrade side surface connected to the lower chord material (not shown). The corroded portions 71 on the reinforcing plate mounting surfaces 12 and 13 are covered with the reinforcing plate 31 shown in FIG. In the box-shaped cross-section diagonal member 11, the other surfaces other than the reinforcing plate attaching surfaces 12 and 13 are reinforcing plate non-attaching surfaces 14 and 15 to which no reinforcing plate is attached.

前記補強方法においては、その後の作業を容易にするため、まず、図６に示すように、前記補強板を取り付ける付近のコンクリート床板８１を掘削して、前記箱形断面斜材１１を補強する作業場所を確保する。次に、前記腐食部７１に対する錆落とし処理と錆止め処理を行う。その後、補強板取付時作業用兼ウレタン充填用孔及び上部ウレタン充填用孔の形成工程と、補強板取付工程と、下側発泡ウレタン充填工程と、上側発泡ウレタン充填工程と、最上部発泡ウレタン充填工程とを行う。   In the reinforcing method, in order to facilitate the subsequent work, first, as shown in FIG. 6, the work of reinforcing the box-shaped oblique member 11 by excavating a concrete floor board 81 in the vicinity of attaching the reinforcing board. Secure a place. Next, a rust removal process and a rust prevention process are performed on the corroded portion 71. After that, the process of forming the reinforcing plate and the urethane filling hole and the upper urethane filling hole, the reinforcing plate attaching process, the lower foamed urethane filling process, the upper foamed urethane filling process, and the uppermost foamed urethane filling Process.

補強板取付時作業用兼ウレタン充填用孔及び上部ウレタン充填用孔の形成工程では、図７に示すように、一つの前記補強板非取付面１５に前記補強板取付時作業用兼ウレタン充填用孔１９を形成すると共に、前記補強板非取付面１５の前記補強板取付時作業用兼ウレタン充填用孔１９の上方位置に前記上部ウレタン充填用孔２１を形成する。前記補強板取付時作業用兼ウレタン充填用孔１９の位置は、前記箱形断面斜材１１において補強板３１が取り付けられる部分の中央位置と対応する前記補強板非取付面１５の位置、すなわち、前記補強板取付面１２，１３における腐食部を覆う補強板３１（図１、図８等に示す）の中央位置と対応する前記補強板非取付面１５の位置とされる。また、前記上部ウレタン充填用孔２１の位置は、前記補強板の上端より所定量（例えば数ｃｍ）上方位置が好ましい。前記補強板取付時作業用兼ウレタン充填用孔１９及び上部ウレタン充填用孔２１のサイズは、前記補強構造で説明した通りである。なお図７の符号７１ａは腐食部を含む部分に対して行った錆落とし処理と錆止め処理後の部分を示す。   In the step of forming the reinforcing plate mounting hole and urethane filling hole and the upper urethane filling hole, as shown in FIG. 7, the reinforcing plate non-mounting surface 15 is attached to the reinforcing plate mounting work and urethane filling hole. The hole 19 is formed, and the upper urethane filling hole 21 is formed on the reinforcing plate non-mounting surface 15 at a position above the reinforcing plate attaching work / urethane filling hole 19. The position of the reinforcing plate attaching work and urethane filling hole 19 is the position of the reinforcing plate non-attaching surface 15 corresponding to the central position of the portion where the reinforcing plate 31 is attached in the box-shaped cross section diagonal member 11, that is, The reinforcing plate non-mounting surface 15 corresponds to the central position of the reinforcing plate 31 (shown in FIGS. 1, 8, etc.) that covers the corroded portions of the reinforcing plate mounting surfaces 12 and 13. Further, the position of the upper urethane filling hole 21 is preferably a predetermined amount (for example, several cm) above the upper end of the reinforcing plate. The sizes of the work-cum-urethane filling hole 19 and the upper urethane-filling hole 21 and the upper urethane filling hole 21 are as described in the reinforcing structure. In addition, the code | symbol 71a of FIG. 7 shows the part after the rust removal process and rust prevention process which were performed with respect to the part containing a corrosion part.

補強板取付工程では、図７に示すように、前記箱形断面斜材１１の補強板取付面１２，１３に締結部材用孔１６を形成し、図８及び図９に示すように、前記腐食部を覆う補強板３１を補強板取付面１２，１３に締結部材４１で取り付ける。本実施例では、前記締結部材４１は高力ボルト４３とナット４４及び普通ボルト４５及びナット４６からなり、前記締結部材用孔１６は高力ボルト用ボルト孔１７と普通ボルト用ボルト孔１８よりなる。前記のように、高力ボルト用ボルト孔１７は前記腐食部７１の上下に各２行×３列で形成され、一方、普通ボルト用ボルト孔１８は、上下の前記高力ボルト用ボルト孔１７間に３行×２列で形成される。なお、前記補強板３１には予め前記補強板取付面１２，１３の高力ボルト用ボルト孔１７及び普通ボルト用ボルト孔１８と合致する位置に、締結部材用孔として高力ボルト用ボルト孔３３と普通ボルト用ボルト孔３４が形成されている。前記補強板３１の取付は、腐食部を覆う前記補強板３１を前記箱形断面斜材１１の補強板取付面１２，１３の外面に配置し、前記補強板取付時作業用兼ウレタン充填用孔１９から前記箱形断面斜材１１内に挿入した締結部材４１の一方の部材を、本実施例では高力ボルト４３及び普通ボルト４５を前記補強板取付面１２，１３及び前記補強板３１の対応する締結部材用孔（ボルト孔）に挿入し、前記補強板３１の外面側に配置した締結部材４１の他方の部材、本実施ではナット４４，４６と結合することにより行う。   In the reinforcing plate attaching step, as shown in FIG. 7, fastening member holes 16 are formed in the reinforcing plate attaching surfaces 12 and 13 of the box-shaped cross section diagonal member 11, and as shown in FIGS. The reinforcing plate 31 covering the part is attached to the reinforcing plate attaching surfaces 12 and 13 by the fastening member 41. In this embodiment, the fastening member 41 comprises a high-strength bolt 43 and a nut 44 and a normal bolt 45 and a nut 46, and the fastening member hole 16 comprises a high-strength bolt bolt hole 17 and a normal bolt bolt hole 18. . As described above, the bolt holes 17 for high-strength bolts are formed in two rows and three columns above and below the corroded portion 71, while the bolt holes 18 for normal bolts are formed on the upper and lower bolt holes 17 for high-strength bolts. It is formed with 3 rows × 2 columns in between. The reinforcing plate 31 has a high-strength bolt bolt hole 33 as a fastening member hole at a position that matches the bolt hole 17 for high-strength bolt and the bolt hole 18 for ordinary bolt on the reinforcing plate mounting surfaces 12 and 13 in advance. A bolt hole 34 for ordinary bolts is formed. The reinforcing plate 31 is mounted by arranging the reinforcing plate 31 covering the corroded portion on the outer surface of the reinforcing plate mounting surfaces 12 and 13 of the box-shaped cross section diagonal member 11 and mounting the reinforcing plate and holes for filling urethane. 19, one member of the fastening member 41 inserted into the box-shaped cross section diagonal member 11 is, in this embodiment, a high-strength bolt 43 and a normal bolt 45 corresponding to the reinforcing plate mounting surfaces 12 and 13 and the reinforcing plate 31. The fastening member 41 is inserted into a fastening member hole (bolt hole) to be connected to the other member of the fastening member 41 disposed on the outer surface side of the reinforcing plate 31, in this embodiment, the nuts 44 and 46.

下側発泡ウレタン充填工程では、まず、図１０のように、前記補強板取付時作業用兼ウレタン充填用孔１９から前記箱形断面斜材１１内に発泡ウレタン注入ノズルＮ１を挿入して前記発泡ウレタン注入ノズルＮ１より、前記発泡ウレタンの液状原料Ｐを、前記締結部材（本実施例では高力ボルト４３及び普通ボルト４５）が位置する前記箱形断面斜材１１の内面（補強板取付面１２，１３の内面）に吹き付け、図１１に示すように前記箱形断面斜材１１の内面に締結部材４１を覆う吹きつけ発泡ウレタン層５２を形成する。前記吹きつけ発泡ウレタン層５２は、発泡時に発揮する接着性によって、前記締結部材の位置する前記箱形断面斜材１１の内面に接着して前記箱形断面斜材１１の内面に確実に密着するため、締結部材用孔（高力ボルト用ボルト孔１７、普通ボルト用ボルト孔１８）に対する封止性を確実にすると共に箱形断面斜材１１の内面に腐食因子が接触するのを防ぎ、前記箱形断面斜材１１内の腐食防止効果を高めることができる。   In the lower foamed urethane filling step, first, as shown in FIG. 10, the foamed urethane injection nozzle N1 is inserted into the box-shaped cross section diagonal member 11 from the urethane loading hole 19 for mounting the reinforcing plate, and the foaming is performed. From the urethane injection nozzle N1, the liquid raw material P of the foamed urethane is converted into an inner surface (reinforcing plate mounting surface 12) of the box-shaped cross section diagonal member 11 where the fastening members (high-strength bolts 43 and ordinary bolts 45 in this embodiment) are located. , 13), and as shown in FIG. 11, a foamed urethane layer 52 is formed on the inner surface of the box-shaped oblique member 11 to cover the fastening member 41. The blown urethane foam layer 52 adheres to the inner surface of the box-shaped cross-section diagonal member 11 and securely adheres to the inner surface of the box-shaped cross-section diagonal material 11 due to the adhesiveness exhibited during foaming. Therefore, the sealing performance for the fastening member holes (the bolt holes 17 for high-strength bolts, the bolt holes 18 for ordinary bolts) is ensured, and the corrosion factor is prevented from coming into contact with the inner surface of the box-shaped oblique member 11. The corrosion prevention effect in the box-shaped oblique member 11 can be enhanced.

次に図１１に示すように、前記発泡ウレタン注入ノズルＮ１より前記箱形断面斜材１１内の下方へ向けて発泡ウレタンの液状原料Ｐを吐出して、図１２に示すように前記補強板取付時作業用兼ウレタン充填用孔１２の下側まで下側発泡ウレタン５３を充填する。前記下側発泡ウレタン５３の充填後、前記補強板取付時作業用兼ウレタン充填用孔１９を覆う綱板からなる蓋部材６１を前記箱形断面斜材１１の補強板非取付面１５の外面に溶接で取り付ける。   Next, as shown in FIG. 11, the foamed urethane liquid material P is discharged from the urethane foam injection nozzle N1 downward in the box-shaped cross section diagonal member 11, and the reinforcing plate is attached as shown in FIG. The lower foamed urethane 53 is filled to the lower side of the hole 12 for working and urethane filling. After the filling of the lower foamed urethane 53, a lid member 61 made of a rope covering the work and urethane filling hole 19 when the reinforcing plate is attached is provided on the outer surface of the reinforcing plate non-attaching surface 15 of the box-shaped cross section diagonal member 11. Install by welding.

上側発泡ウレタン充填工程では、図１３に示すように、前記上部ウレタン充填用孔２１から挿入した発泡ウレタン注入ノズルＮ２より発泡ウレタンの液状原料Ｐを吐出して、図１４に示すように前記下側発泡ウレタン５３上に前記上部ウレタン充填用孔２１の下側まで上側発泡ウレタン５５を充填する。   In the upper urethane foam filling step, as shown in FIG. 13, the liquid raw material P of urethane foam is discharged from the urethane foam injection nozzle N2 inserted through the upper urethane filling hole 21, and the lower side is filled as shown in FIG. The upper urethane foam 55 is filled on the foamed urethane 53 to the lower side of the upper urethane filling hole 21.

最上部発泡ウレタン充填工程では、図１４に示すように、前記上部ウレタン充填用孔２１から箱形断面斜材１１内にＵ字状に屈曲した発泡ウレタン注入ノズルＮ３を挿入して、前記上部ウレタン充填用孔２１よりも上方の前記箱形断面斜材１１の補強板非取付面１５の内面１１ａに発泡ウレタンの液状原料Ｐを吐出し、該吐出した発泡ウレタンの液状原料Ｐを前記上部ウレタン充填用孔２１へ流下させると共に、前記上部ウレタン充填用孔２１に封止用ボルト６３（図１及び図２に示す）を前記箱形断面斜材１１の外側から装着し、前記流下した発泡ウレタンの液状原料から形成された最上部発泡ウレタン５７で前記箱形断面斜材１１内の前記封止用ボルト６３の周縁を封止する。前記補強板非取付面１５の内面１１ａを流下する発泡ウレタンの液状原料から形成される最上部発泡ウレタン５７は、発泡時の接着性により、前記上部ウレタン充填用孔２１周辺の補強板非取付面１５の内面１１ａ及び前記封止用ボルト６３に接着して前記上部ウレタン充填用孔２１周辺の補強板非取付面１５の内面１１ａ及び前記封止用ボルト６３に確実に密着する。これにより、前記上部ウレタン充填用孔２１周辺の封止性を確実なものにし、前記上部ウレタン充填用孔２１から前記箱形断面斜材１１内への腐食因子の侵入を防止し、前記箱形断面斜材内１１の腐食防止効果を高めることができる。なお、前記補強方法による補強終了後、前記コンクリート床板８１の掘削部分は元の状態に戻される。   In the uppermost urethane foam filling step, as shown in FIG. 14, a urethane foam injection nozzle N3 bent in a U-shape is inserted into the box-shaped cross section diagonal member 11 from the upper urethane filling hole 21, and the upper urethane is filled. The foamed urethane liquid material P is discharged onto the inner surface 11a of the reinforcing plate non-mounting surface 15 of the box-shaped oblique member 11 above the filling hole 21, and the discharged urethane foam liquid material P is filled with the upper urethane. The sealing bolt 63 (shown in FIG. 1 and FIG. 2) is attached to the upper urethane filling hole 21 from the outside of the box-shaped cross section diagonal member 11, and the foamed urethane foam flows down. The periphery of the sealing bolt 63 in the box-shaped oblique member 11 is sealed with an uppermost foamed urethane 57 formed from a liquid raw material. The uppermost foamed urethane 57 formed from a liquid material of urethane foam that flows down the inner surface 11a of the reinforcing plate non-attaching surface 15 has a reinforcing plate non-attaching surface around the upper urethane filling hole 21 due to adhesiveness during foaming. It adheres to the inner surface 11a of the 15 and the sealing bolt 63, and firmly adheres to the inner surface 11a of the reinforcing plate non-mounting surface 15 around the upper urethane filling hole 21 and the sealing bolt 63. Thereby, the sealing property around the upper urethane filling hole 21 is ensured, the penetration of the corrosion factor from the upper urethane filling hole 21 into the box-shaped cross section diagonal member 11 is prevented, and the box shape The effect of preventing corrosion in the cross section diagonal member 11 can be enhanced. In addition, after completion | finish of reinforcement by the said reinforcement method, the excavation part of the said concrete floor board 81 is returned to the original state.

このように、本発明の補強構造及び補強方法は、アーク溶射等の面倒な作業が不要であるため、橋上の道路を閉鎖することなく容易に腐食部を補強することが可能である。しかも、本発明の補強方法によって補強された下路鋼トラス橋の箱形断面斜材は、腐食部が補強板で補強されていると共に、補強板が取り付けられた部分の箱形断面斜材内に充填された発泡ウレタンによって箱形断面斜材の内面が腐食因子と接触するのが防止されるため、補強板取付の際に生じる箱形断面斜材の密閉解除による腐食を防止することができる。なお、前記実施例では、締結部材をボルトとナットで構成したが、他の構成からなるものであってもよい。   As described above, the reinforcing structure and the reinforcing method according to the present invention do not require troublesome work such as arc spraying, and therefore can easily reinforce the corroded portion without closing the road on the bridge. Moreover, the box-shaped diagonal member of the lower steel truss bridge reinforced by the reinforcing method of the present invention has a corroded portion reinforced with a reinforcing plate and a portion of the box-shaped diagonal member to which the reinforcing plate is attached. The foamed urethane filled in the box prevents the inner surface of the box-shaped cross section diagonal material from coming into contact with the corrosion factor. . In the above-described embodiment, the fastening member is composed of a bolt and a nut, but may be composed of other structures.

本発明の補強構造で補強された下路鋼トラス橋の箱形断面斜材の一部を示す斜視図である。It is a perspective view which shows a part of box-shaped cross-section diagonal material of the lower road steel truss bridge reinforced with the reinforcement structure of this invention. 図１の２−２断面図である。It is 2-2 sectional drawing of FIG. 図１の３−３断面図である。FIG. 3 is a 3-3 cross-sectional view of FIG. 1. 図１の４−４断面図である。FIG. 4 is a sectional view taken along the line 4-4 in FIG. 1. 図１の５−５断面図である。FIG. 5 is a sectional view taken along line 5-5 in FIG. 1. 本発明の補強方法の一実施例において箱形断面斜材周囲のコンクリート床版を掘り起こした状態を示す斜視図である。It is a perspective view which shows the state which dug up the concrete floor slab around box-shaped cross-section diagonal material in one Example of the reinforcement method of this invention. 同実施例において箱形断面斜材に補強板取付時作業用兼ウレタン充填用孔等を形成した状態を示す斜視図である。It is a perspective view which shows the state which formed the hole for work and urethane filling at the time of a reinforcement board attachment in the box-shaped cross-section diagonal in the Example. 同実施例において箱形断面斜材に補強板を固定した状態を示す斜視図である。It is a perspective view which shows the state which fixed the reinforcement board to the box-shaped cross-section diagonal in the Example. 図８の９−９断面図である。It is 9-9 sectional drawing of FIG. 同実施例において発泡ウレタンの液状原料吹き付けを示す断面図である。It is sectional drawing which shows the liquid raw material spraying of urethane foam in the Example. 同実施例において下側発泡ウレタンの充填を示す断面図である。It is sectional drawing which shows filling with lower side urethane foam in the Example. 同実施例において下側発泡ウレタンの充填後を示す断面図である。It is sectional drawing which shows after filling with lower side urethane foam in the Example. 同実施例において上側発泡ウレタンの充填を示す断面図である。It is sectional drawing which shows filling with an upper foaming urethane in the Example. 同実施例において上部ウレタン充填用孔よりも上方の箱形断面斜材の内面に発泡ウレタンの液状原料を吐出する際を示す断面図である。It is sectional drawing which shows the time of discharging the liquid raw material of a foaming urethane to the inner surface of the box-shaped cross-section diagonal material above the upper urethane filling hole in the same Example. 下路鋼トラス橋の一例を示す斜視図である。It is a perspective view which shows an example of a lower steel truss bridge. 下路鋼トラス橋の箱形断面斜材の腐食部を示す斜視図である。It is a perspective view which shows the corrosion part of the box-shaped cross-section diagonal material of a lower steel truss bridge.

符号の説明Explanation of symbols

１０ 下路鋼トラス橋
１１ 箱形断面斜材
１２，１３ 補強板取付面
１４，１５ 補強板非取付面
１９ 補強板取付時作業用兼ウレタン充填用孔
２１ 上部ウレタン充填用孔
３１ 補強板
４１ 締結部材
４３ 高力ボルト
４４ 高力ボルト用ナット
４５ 普通ボルト
４６ 普通ボルト用ナット
５１ 発泡ウレタン
５２ 吹きつけ発泡ウレタン層
５３ 下側発泡ウレタン
５５ 上側発泡ウレタン
５７ 最上部発泡ウレタン
６１ 蓋部材
６３ 封止用ボルト DESCRIPTION OF SYMBOLS 10 Lower steel truss bridge 11 Box-shaped oblique member 12, 13 Reinforcement plate attachment surface 14, 15 Reinforcement plate non-attachment surface 19 Hole for work and urethane filling when attaching reinforcement plate 21 Upper urethane filling hole 31 Reinforcement plate 41 Fastening Member 43 High-strength bolt 44 High-strength bolt nut 45 Normal bolt 46 Normal bolt nut 51 Urethane foam 52 Sprayed urethane layer 53 Lower foamed urethane 55 Upper foamed urethane 57 Uppermost foamed urethane 61 Lid member 63 Sealing bolt

Claims (5)

下路鋼トラス橋の箱形断面斜材の外面に発生した腐食部を補強板で覆う補強構造において、
前記腐食部を覆う補強板を締結部材で前記箱形断面斜材の外面に取り付け、
前記補強板を取り付けた部分の前記箱形断面斜材内部に発泡ウレタンを充填して前記箱形断面斜材の内面と前記発泡ウレタンを密着させたことを特徴とする下路鋼トラス橋の箱形断面斜材の補強構造。 In the reinforcement structure that covers the corroded part that occurred on the outer surface of the box-shaped diagonal member of the lower steel truss bridge with a reinforcing plate,
A reinforcing plate that covers the corroded portion is attached to the outer surface of the box-shaped diagonal member with a fastening member,
A box for a steel truss bridge with a lower road, in which urethane foam is filled inside the box-shaped oblique member of the portion to which the reinforcing plate is attached, and the inner surface of the box-shaped oblique member and the urethane foam are brought into close contact with each other. Reinforced structure with diagonal cross section. 前記補強板は前記箱形断面斜材の腐食部よりも上方部位と下方部位を高力ボルトとナットからなる前記締結部材で前記箱形断面斜材に固定し、前記上方部位と前記下方部位間を普通ボルトとナットからなる前記締結部材で前記箱形断面斜材に固定したことを特徴とする請求項１に記載の下路鋼トラス橋の箱形断面斜材の補強構造。   The reinforcing plate is fixed to the box-shaped cross-section diagonal member with the fastening member made of high-strength bolts and nuts above and below the corroded portion of the box-shaped cross-section diagonal material. The reinforcing structure of the box-shaped cross section diagonal member of the lower steel truss bridge according to claim 1, wherein the box-shaped cross section diagonal member is fixed to the box-shaped cross section diagonal member by the fastening member comprising a normal bolt and a nut. 下路鋼トラス橋の箱形断面斜材の外面に発生した腐食部を覆う補強板を前記箱形断面斜材の外面に取り付けて補強する方法において、
前記箱形断面斜材の少なくとも一面は前記補強板を取り付けない補強板非取付面とし、
前記補強板が取り付けられる部分の中央位置と対応する前記補強板非取付面の位置には補強板取付時作業用兼ウレタン充填用孔を形成すると共に、前記補強板非取付面の前記補強板取付時作業用兼ウレタン充填用孔の上方位置に上部ウレタン充填用孔を形成し、
前記腐食部を覆う前記補強板を前記箱形断面斜材の外面に配置し、前記補強板取付時作業用兼ウレタン充填用孔から前記箱形断面斜材内に挿入した締結部材の一方の部材と前記補強板の外面側に配置した締結部材の他方の部材とで前記補強板を前記箱形断面斜材の外面に取り付け、
前記補強板取付時作業用兼ウレタン充填用孔から前記箱形断面斜材内に発泡ウレタン注入ノズルを挿入し、前記発泡ウレタン注入ノズルより前記箱形断面斜材内に発泡ウレタンの液状原料を吐出して前記補強板取付時作業用兼ウレタン充填用孔の下側まで下側発泡ウレタンを充填し、
前記補強板取付時作業用兼ウレタン充填用孔を覆う蓋部材を前記箱形断面斜材の外面に溶接で取り付け、
前記上部ウレタン充填用孔から挿入した発泡ウレタン注入ノズルより発泡ウレタンの液状原料を吐出して前記下側発泡ウレタン上に前記上部ウレタン充填用孔の下側まで上側発泡ウレタンを充填し、
その後、前記上部ウレタン充填用孔よりも上方の前記箱形断面斜材の内面に発泡ウレタンの液状原料を吐出して、該吐出した発泡ウレタンの液状原料を前記上部ウレタン充填用孔へ流下させると共に、前記上部ウレタン充填用孔に封止用ボルトを前記箱形断面斜材の外側から装着し、前記流下した発泡ウレタンの液状原料から形成された発泡ウレタンで前記箱形断面斜材内の前記封止用ボルトの周縁を封止することを特徴とする下路鋼トラス橋の箱形断面斜材の補強方法。 In the method of attaching and reinforcing the reinforcing plate covering the corroded portion generated on the outer surface of the box-shaped diagonal member of the lower steel truss bridge in the box-shaped diagonal member,
At least one surface of the box-shaped cross section diagonal is a reinforcing plate non-attaching surface to which the reinforcing plate is not attached,
At the position of the reinforcing plate non-mounting surface corresponding to the center position of the portion to which the reinforcing plate is mounted, a hole for working and urethane filling when the reinforcing plate is mounted is formed, and the reinforcing plate mounting of the non-reinforcing plate mounting surface The upper urethane filling hole is formed at the upper position of the hole for working and urethane filling,
One member of a fastening member in which the reinforcing plate that covers the corroded portion is disposed on the outer surface of the box-shaped cross-section diagonal member and is inserted into the box-shaped cross-section diagonal member from the hole for work and urethane filling when the reinforcing plate is attached And the other member of the fastening member arranged on the outer surface side of the reinforcing plate, the reinforcing plate is attached to the outer surface of the box-shaped cross section diagonal member,
Insert the urethane foam injection nozzle into the box-shaped cross section diagonal material from the hole for work and urethane filling when the reinforcing plate is installed, and discharge the liquid material of urethane foam into the box-shaped cross section diagonal material from the foam urethane injection nozzle And filling the lower foamed urethane to the lower side of the hole for working and urethane filling when the reinforcing plate is attached,
A lid member that covers the hole for work and urethane filling when the reinforcing plate is attached is attached to the outer surface of the box-shaped oblique member by welding,
The upper urethane foam is filled up to the lower side of the upper urethane filling hole by discharging a liquid raw material of urethane foam from the urethane foam injection nozzle inserted from the upper urethane filling hole,
Thereafter, a liquid material of urethane foam is discharged onto the inner surface of the box-shaped oblique member above the upper urethane filling hole, and the discharged liquid material of foamed urethane flows down to the upper urethane filling hole. A sealing bolt is attached to the upper urethane filling hole from the outside of the box-shaped cross section diagonal member, and the sealing inside the box-shaped cross section diagonal member is made of foamed urethane formed from the liquid material of the foamed urethane that has flowed down. A method for reinforcing a box-shaped diagonal member of a lower steel truss bridge, characterized by sealing a peripheral edge of a stop bolt. 前記補強板は前記箱形断面斜材の腐食部よりも上方部位と下方部位を高力ボルトとナットからなる前記締結部材で前記箱形断面斜材に固定し、前記上方部位の高力ボルトと前記下方部位の高力ボルト間を普通ボルトとナットからなる前記締結部材で前記箱形断面斜材に固定することを特徴とする請求項３に記載の下路鋼トラス橋の箱形断面斜材の補強方法。   The reinforcing plate is fixed to the box-shaped oblique member with the fastening member comprising a high-strength bolt and a nut at an upper part and a lower part than the corroded portion of the box-shaped oblique member, 4. The box-shaped cross section diagonal member of the lower steel truss bridge according to claim 3, wherein a space between the high-strength bolts in the lower portion is fixed to the box-shaped cross section diagonal member by the fastening member comprising a normal bolt and a nut. Reinforcement method. 前記下側発泡ウレタンの充填時に、前記締結部材が位置する前記箱形断面斜材の内面に前記発泡ウレタンの液状原料を吹き付けることを特徴とする請求項３または４に記載の下路鋼トラス橋の箱形断面斜材の補強方法。
The lower road steel truss bridge according to claim 3 or 4, wherein a liquid raw material of the urethane foam is sprayed on an inner surface of the box-shaped oblique member in which the fastening member is located when the lower urethane foam is filled. To reinforce the box-shaped cross section diagonal.

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