JP5928944B2 - Improvement method of abutment chest wall - Google Patents

Description

  The present invention relates to an improved construction method for an abutment chest wall that widens a narrow gap between a bridge end of a road bridge or a railway bridge and the abutment chest wall.

In general, a gap is provided between the abutment and the bridge girder so as not to constrain the expansion and contraction and rotation of the bridge girder due to annual or daily temperature changes, and rotation caused by vehicles passing through the bridge girder. The width of this gap varies depending on the size of the bridge, and is usually several centimeters to several tens of centimeters. In addition, there is an extension device installed between the abutment and the bridge girder that does not hinder the expansion and contraction of the bridge girder and does not block the passage of the vehicle. Rainwater does not leak from this device to the end of the bridge girder, the support section, or the substructure. The water stop function is given.
However, due to aging and structural defects of the expansion / contraction device due to changes over time, the water stop function of the expansion / contraction device is lost, and rainwater or the like leaks to the end or support portion of the bridge girder. If this water leakage is repeated, the deterioration of the bridge function such as the corrosion of steel members in steel girders and concrete bridge girders proceeds. In particular, in cold regions, the water leakage during the winter season contains a large amount of antifreeze components, so that the corrosion of the steel material proceeds rapidly and the edge of the bridge deteriorates rapidly.
In addition, in PC (Prestressed Concrete) bridges, the anchorage of PC steel is concentrated at the end of the bridge girder. To ensure the soundness of this part, the service life of the bridge is completed. Very important.
Therefore, as described in Patent Document 1, a method for repairing water leakage at a portion having a narrow gap between bridges has been proposed. Alternatively, as described in Patent Document 2, there has been proposed an apparatus and a method for repairing a bridge girder end by directly penetrating a deteriorated portion from a narrow gap. Further, Patent Document 3 describes the idea of securing a space on the back surface of the abutment portion of the bridge.

JP 2008-69596 A Japanese Patent Laid-Open No. 2007-218048 Japanese Patent No. 4167149

However, the conventional bridge structure has a drawback that the gap between the abutment and the existing bridge is narrow and that inspection and repair are difficult.
In addition, as described in Patent Document 1, a method of inserting a swellable water stop tube between narrow play and repairing the water leak by the restoring force of the tube simply stops the water leak temporarily and removes the already deteriorated portion. It cannot be recovered.
Moreover, in the apparatus and method for repair as described in Patent Document 2, a resin sheet and a spacer are installed at a suspended portion with the same dimensions as before, and concrete is reinjected. It does not expand the space. For this reason, it is not possible to sufficiently check and inspect the effects after repair work.
Patent document 3 enlarges the space on the back of the abutment, but constructs a new abutment for the bridge in the expanded space and replaces the bridge. The space will be secured using earth retaining walls and tensile reinforcement after the use of the bridge is stopped. After a new abutment is built in the space, the existing abutment will be removed and a new bridge will be built. The present invention is different from the present invention in traffic regulation conditions during construction, space securing methods, and securing purposes.

  This invention secures the space necessary for inspection and repair on the back of the bridge, facilitates repair and reinforcement work for the deteriorated part of the bridge end, and effects after repair and reinforcement work close to the place where the work was carried out The use of pre-cast members can be completed in a short period of time, and traffic lane restrictions such as partial lane restrictions, daytime restrictions, and nighttime restrictions according to the conditions at the site. It is intended to provide an improved method for abutment chest wall that can be applied to various traffic regulations, such as daytime and nighttime regulations and combinations of traffic zones and time zone regulations.

The present invention has the following contents.
(1) The improvement method of the abutment part chest wall according to the present invention includes an excavation process for excavating a back surface of the existing chest wall when traffic is interrupted, an existing chest wall removal process for tearing down the existing chest wall, and the existing chest wall within a range excavated in the excavation process A new chest wall was installed at a position retreated from the position of the chest wall to secure a space between the bridge end and the chest wall, and after installing the new chest wall in the chest wall installation step, drilled on the back of the new chest wall A backfilling process for refilling the area, and an extension device receiver installed at the bridge end, a new delivery plate is installed on the chest wall, and an extension device is installed between the extension device receiver and the new delivery plate. And a road surface restoration process for restoring the road surface such as re-paving and route restoration on the new delivery version.
(2) In the improved construction method of the abutment battlements as described in (1), a part of the existing road is removed before the excavation process, and a support block is installed on the removed road. Providing a traffic securing step for securing traffic by installing a temporary delivery plate between the abutment part chest wall and excavating the back soil of the existing chest wall after removing the temporary delivery plate at the time of traffic interruption in the excavation process It is characterized by.
(3) In the improvement method of the abutment part chest wall described in (1) or (2), the new chest wall in the chest wall installation step is a precast member manufactured in advance.
(4) In the improvement method of the abutment part chest wall described in (1) to (3), the cross section of the new chest wall in the chest wall installation step has a shape similar to an inverted T-shape.
(5) In the improvement method of the abutment part chest wall as described in (1) to (4), in the backfilling step, the backfilling material uses improved soil in which soil, cement, water, etc. are mixed. .
(6) (1) to (5) definitive an improvement method of abutment portions chest wall according to, in the road restoration step, stretching apparatus to be installed, even if the possibility of water leakage caused by aging of the extension device girders It is characterized by being installed at a position separated from the end of the bridge girder according to the situation of the site or structure so that it does not leak directly at the end.

According to the improvement method of the abutment part chest wall of the present invention, the excavation step of excavating the back of the existing chest wall at the time of traffic interruption, the existing chest wall removal step of breaking the existing chest wall, and the existing chest wall within the range excavated in the excavation step The new chest wall is installed at a position retreated from the position, the chest wall installation process to secure a space between the bridge end and the chest wall, and the area drilled on the back of the new chest wall after installing the new chest wall in the chest wall installation process And a backfilling process for backfilling, and installing a telescopic device receiver on the bridge end, bridging a new delivery plate on the chest wall, installing a telescopic device between the telescopic device receiver and the new delivery plate, Since it consists of a road surface restoration process that restores the road surface, such as re-paving and route restoration on the new delivery version, inspection and repairs are made so that workers can enter by expanding the gap between the narrow abutment and the existing bridge. And make it possible Traffic cut-off period that can be shortened.
Prior to the excavation process, part of the existing road was removed from the pavement and stepping plates, a support block was installed on the removed road, and a temporary transfer plate was installed between the support block and the abutment chest wall. A traffic securing step is secured, and after removing the temporary transfer plate at the time of traffic interruption in the excavation step, the back soil of the existing chest wall is excavated, so the traffic interruption period on the existing road can be shortened.
In addition, since the new chest wall in the chest wall installation process is a precast member manufactured in advance, the new chest wall in the chest wall installation process when the construction period needs to be shortened by using a precast member manufactured in advance, The member can be made small and thin, and transportation and erection work can be facilitated, and the chest wall concrete placement on site is not required, and the work period on site can be shortened.
In addition, since the cross section of the new chest wall in the chest wall installation process has a shape similar to an inverted T-shape, it is in a stable state during transportation and erection, and each work can be performed safely and in a short time.
In the backfilling process, the backfilling material uses improved soil mixed with soil, cement, water, etc., so it has high resistance to ground subsidence and earthquake motion, easy workability, and excellent economic efficiency. doing.
In addition, in the road surface restoration process , the telescopic device to be installed can be changed from the end of the bridge girder to the situation of the site or structure so that it does not leak directly even if there is a possibility of water leakage due to aging of the telescopic device. Because it is installed at a separate position accordingly, the life of the bridge girder can be reliably extended.

FIG. 1 is an explanatory view showing an end of a bridge before construction in an improved method for abutment chest wall according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing a bridge end portion after construction when a support block is necessary due to traffic regulation or the like in the improved method of abutment chest wall according to an embodiment of the present invention. FIG. 3 is an explanatory diagram showing a bridge end portion after construction when a support block is not required due to traffic blocking or the like in the improved method of abutment chest wall according to an embodiment of the present invention. FIG. 4 is a cross-sectional configuration diagram of the road portion in FIG. 1. FIG. 5 is a cross-sectional configuration diagram showing the position of the support block when the overtaking lane side is being constructed. FIG. 6 is an explanatory view showing a state in which a temporary transfer plate is installed on the road portion in the improved method of the abutment chest wall. FIG. 7 is a cross-sectional configuration diagram of a road portion in which a support block and a temporary delivery plate are installed in both the traveling lane and the overtaking lane. FIG. 8 is an explanatory diagram showing an example in which the temporary delivery version is divided. FIG. 9 is an explanatory diagram showing a point when the temporary excavation plate is removed and primary excavation is performed. FIG. 10 is an explanatory diagram showing a point in the case where the temporary excavation plate is removed and the secondary excavation is performed. FIG. 11 is an explanatory diagram showing a countermeasure example when it is necessary to prevent the slope from collapsing during secondary excavation. FIG. 12 is an explanatory diagram showing a case where the secondary excavation is completed. FIG. 13 is an explanatory view showing a chest wall installation step. FIG. 14 is an explanatory view showing the state after the existing abutment chest wall is removed. FIG. 15 is an explanatory view showing a combined state of the new chest wall. FIG. 16 is an explanatory view showing the backfilling step. FIG. 17 is an explanatory diagram showing the completion of the backfilling process. FIG. 18 is an explanatory view showing a road surface restoration process for installing a new delivery plate, re-paving, and installing an expansion / contraction device in the improvement method of the abutment chest wall. FIG. 19 is an explanatory view showing another type of the new chest wall in the improvement method of the abutment chest wall. FIG. 20 is an explanatory view showing another type of the new chest wall in the improvement method of the abutment chest wall. FIG. 21 is explanatory drawing which shows the other kind of new chest wall in the improvement method of the abutment part chest wall. FIG. 22 is an explanatory view showing an example in which a new delivery version is installed on a new chest wall.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. FIG. 1 is an explanatory view of a side surface showing an end portion of a bridge girder and a chest wall improvement portion before construction in the improvement method of an abutment chest wall according to an embodiment of the present invention, and FIG. 2 regulates traffic only at night, for example. It is a side view which shows the bridge edge part after construction when construction is carried out by carrying out construction and releasing traffic during the daytime. Here, the abutment chest wall improvement method 10 according to the present invention includes an excavation step 17 for excavating the back of the existing chest wall (abutment portion chest wall 14) when traffic is interrupted, an existing chest wall removal step 19 for breaking the existing chest wall, and the excavation step. A new chest wall 20 is installed at a position retreated from the position of the existing chest wall 14 within the range excavated in step 17, and a chest wall installation step 18 for securing a space between the bridge end and the chest wall; After the new chest wall is installed, a backfilling step 22 for backfilling the excavated area on the back of the new chest wall, an expansion device receiver 28 is installed at the end of the bridge, and a new delivery plate 26 is installed on the chest wall. A telescopic device is installed between the telescopic device receiver 28 and the new delivery plate 26, and a road surface restoration step 27 is performed on the new delivery plate 26 to restore the road surface, such as re-paving and line restoration.

The new chest wall 20 has a precast structure and a cast-in-place concrete structure, and can be selected in consideration of on-site conditions. The new chest wall 20 in the case where it is desired to complete the construction in a short period of time, such as when traffic is restricted only at night and the traffic is released during the day, is precast that is manufactured in advance elsewhere. FIG. 3 shows the traffic of the construction section such as the construction of one side lane or the side lane in the improved construction method of the abutment part chest wall according to one embodiment of the present invention by restricting the traffic day and night. It is a side view which shows the bridge edge part after construction in case the restriction | limiting to interrupt | block is possible and the support block 13 is unnecessary. However, if it is necessary to support the new delivery plate 26 due to conditions during construction, the support block 13 may be provided. After removing the pavement 11 and the stepping plate 12 of the existing structure other than the steps necessary for releasing the traffic in the traffic securing process 16, the excavation process 17 removes the embankment on the back of the abutment chest wall 14 in the excavation range 21. Do excavation. The new chest wall support plate 29 and the new chest wall 20 are installed at the location where excavation is performed, the abutment part chest wall 14 is removed, the ground improvement soil 31 by the ground improvement process 30 is backfilled in the excavation area 21, and the expansion device 25 is expanded and contracted. In addition to the telescopic device installation process 40 for installing the device receiver 28, a new delivery plate 26 is installed, and a road surface restoration process 27 for restoring pavement, routes, and the like thereon.
The production of the new chest wall 20 has a precast structure and a cast-in-place concrete structure, and is selected in consideration of on-site conditions. When it is not necessary to release traffic or there are few restrictions on the construction period, it is economically advantageous to use cast-in-place concrete for the new chest wall 20 and the support block 13 in the chest wall installation process.

The description will be made under the traffic regulation conditions of FIG. The traffic securing step 16 secures traffic of the vehicle during construction. A temporary transfer plate 15 is installed between the newly installed support block 13 and the existing abutment chest wall 14 and the end of the bridge to secure traffic. FIG. 4 is a cross-sectional configuration diagram of the road before construction. The traffic securing process 16 secures traffic by constructing a part of an existing road and a lane on one side. For example, when constructing the overtaking lane side first, the pavement 11 and the stepping plate 12 on the overtaking lane side are removed, the support block 13 is installed on the removed road portion, and the support block 13 and the abutment part chest wall 14 are A temporary delivery plate 15 is installed between them (see FIGS. 5 to 8). The temporary delivery plate 15 is supported by the support block 13, the abutment part chest wall 14, and the end of the bridge girder. When it is expected that the amount of rotation and expansion / contraction of the bridge girder generated at the end of the bridge girder will increase, a movable part may be provided on the support part of the end of the bridge girder.
If the construction of one side lane is not completed overnight, such as when implementing traffic regulation only at night, remove the pavement 11 and the stepping plate 12 in the range of the support block 13 and install the support block 13 After that, the pavement 11 is restored and traffic is released in the daytime. Even while the overtaking lane side is being constructed, the vehicle can pass through the traveling lane side, and the traffic of the vehicle is not completely stopped.

  FIG. 5 shows a cross-sectional view of the support block position after the temporary delivery plate 15 is installed, and FIG. 6 shows a side view after the temporary delivery plate 15 is installed. A temporary transfer plate 15 on the overtaking lane side is installed to switch the lane for traffic regulation, and the traveling lane side is constructed. In the construction on the traveling lane side, the support block 13 is similarly installed, and the temporary delivery plate 15 is installed between the support block 13 and the abutment part chest wall 14. During this construction, the vehicle passes over the temporary delivery plate 15 previously constructed. Thus, the traffic of the vehicle can be ensured by constructing each lane. FIG. 7 shows a cross-sectional view of the position of the support block 13 after the support block 13 and the temporary transfer plate 15 are installed in each lane.

  Since the temporary delivery plate 15 has a structure that can withstand the load of traffic that travels and secures traveling performance, it is possible to secure the safety of traffic that passes through the corresponding construction section when the abutment chest wall is improved. The structure of the temporary delivery plate 15 is selected from a concrete structure, a steel structure, and a composite structure of steel and concrete in consideration of the span length between the support block 13 and the abutment chest wall 14. The temporary delivery plate 15 may be divided in consideration of weight, and FIG. 8 shows an example in which the temporary delivery plate 15 is divided into four. The number of division of the temporary delivery plate 15 can be changed in consideration of the traffic regulation state, the weight of the temporary delivery plate 15 and the like.

  In the excavation process 17, first, traffic is interrupted at night, etc., and then the temporary delivery plate 15 that has been bridged to secure traffic is removed between the support block 13 and the abutment chest wall 14, and the bottom is excavated. (See FIG. 9). Moreover, when the construction time for excavation is limited, or when there is a possibility that the ground will collapse when excavated at once, excavation can be performed in several steps. In the present embodiment, a case where excavation is divided into two times of primary excavation and secondary excavation will be described. In addition, the primary excavation and secondary excavation planned in this construction method will be carried out in the same way on both the driving lane and the overtaking lane. FIG. 10 illustrates the case of secondary excavation. Here, the secondary excavation start point is determined in consideration of the load acting on the support block 13, the state of the ground to be excavated, and the performance of the material used in the backfilling process. FIG. 11 shows a case where it is necessary to prevent the slope of the secondary excavation from collapsing from the ground state, and a ground collapse prevention plate 23 is installed in the vicinity of the secondary excavation starting point. FIG. 12 shows a state where the primary excavation and the secondary excavation are completed. Secondary excavation will be carried out on both lanes in the same way. At the time of construction, the temporary delivery plate 15 is removed and installed as necessary.

In the chest wall installation step 18, as shown in FIG. 13, the new chest wall 20 is placed on the new chest wall support plate 29, and is fixed to the abutment with the new chest wall fixture 36, and between the bridge end and the chest wall. Secure space.
In the existing chest wall removal step 19, as shown in FIG. 14, after the new chest wall 20 is fixed to the abutment with the new chest wall fixture 36, the existing chest wall 14 is removed. By removing the existing chest wall 14, a space 39 for inspection / investigation and repair / reinforcement can be secured between the new chest wall 20 and the bridge end.

  In the ground improvement process 30, the new chest wall support plate 29 and the new chest wall 20 are installed at the location where excavation is performed, the abutment part chest wall 14 is removed, and the ground improvement soil 31 is backfilled in the excavation range 21. FIG. 13 shows the state of the side surface when the new chest wall 20 is installed. The ground adjustment of the place where the new chest wall 20 is installed at the place where the secondary excavation has been performed is performed, and the new chest wall 20 is installed after the new chest wall support plate 29 is laid. At the time of construction, the temporary delivery plate 15 is removed and installed as necessary. After installation, it is fixed to the existing abutment using the new chest wall fixture 36. When the ground condition is good and the possibility of ground subsidence occurring after the installation of the new chest wall 20 is small, the installation of the new chest wall support plate 29 is unnecessary. Alternatively, leveled concrete or leveled mortar may be applied instead of the new chest wall support plate 29. The new chest wall fixture 36 should not be used when the situation of the structure to be constructed and the safety at the time of construction or after completion can be secured, or it can be changed to a simple device using steel plates or bolts. Sometimes.

  The new chest wall 20 is manufactured by being divided into sizes that can be transported in a factory. After the new chest wall 20 is installed, the divided blocks are integrated using PC steel. After the new chest wall 20 can support the load of the temporary delivery plate 15, the abutment part chest wall 14 is removed. FIG. 14 shows a state after the abutment chest wall 14 is removed. The cross-sectional shape of the new chest wall 20 includes an inverted T-shape, a U-shape, and an L-shape. Inverted T-shape is suitable, but depending on conditions, construction may be possible even in U-shape or L-shape. FIG. 15 shows a state in which the block of the new chest wall 20 is integrated using the PC steel material 38 for coupling. When integrating the new chest wall 20, when the blocks are integrated, the existing abutment wing 37 can also be integrated with the PC wall material 38 for coupling together with the new chest wall 20. Depending on the construction conditions such as the size of the new chest wall 20 and the backfill material, it is possible to connect with a steel bar other than the connecting PC steel 38, for example.

  In the backfilling step 22, the ground improvement soil 31 is backfilled in the place where the back of the new chest wall 20 has been excavated. The traffic is interrupted at night or the like, and the temporary delivery plate 15 spanned between the support block 13 and the abutment part chest wall 14 is removed and backfilled. Here, as the ground improvement soil 31 used for backfilling, it is necessary to select a material that does not sink due to the influence of a passing vehicle. For example, raw material soil, cement and water, raw material soil, cement, water and air bubbles are mixed and used for backfilling. Further, the ground improvement soil 31 can be used as it is if the removed backfill soil can be sufficiently compacted in consideration of the construction conditions such as the construction period. In addition, improved soil and soil mixed with cement-based solidifying material, cement, water-mixed lightweight soil mixed with water and bubbles, mortar mixed with cement and sand, foamed polystyrene, and the like can be used. Depending on the state of use after the completion of this improvement method, the backfilling step 22 may be completed with a gap between the ground improvement soil 31 and the temporary delivery plate 15. 16 and 17 are diagrams for explaining the backfilling step 22 in which no gap is provided between the temporary delivery plates 15.

In the expansion / contraction device installation step 40, the expansion / contraction device receiver 28 and the expansion / contraction device 25 are installed. In the re-paving step 27, the new delivery plate 26 is installed and the road surface is restored by re-paving or the like (see FIG. 18). The new delivery plate 26 is classified into a precast structure manufactured in advance elsewhere, a half precast structure in which embedded formwork and cast-in-place concrete are combined, depending on the manufacturing method. Further, the new delivery plate 26 is classified according to the structure into a PC structure, a reinforced concrete structure, a composite structure of steel and concrete, and the like.
In the telescopic device installation step 40, the telescopic device 25 to be installed is located away from the end of the bridge girder via the telescopic device receiver 28 so that the bridge end does not get wet even when water leaks due to aging of the telescopic device. Install in. When the expansion / contraction amount of the bridge is small and the expansion / contraction device 25 does not need to be provided, the new delivery plate 26 and the bridge body may be directly joined without providing the expansion / contraction device 25 and the expansion / contraction device receiver 28. The expansion device receiver 28 is classified according to the manufacturing method into a precast structure manufactured in advance elsewhere, a half precast structure in which an embedded formwork and cast-in-place concrete are combined, and cast-in-place concrete structure.

  The construction method 10 of the abutment chest wall configured as described above is to completely block traffic during the time required for construction even under severe conditions in which traffic is restricted only during nighttime and traffic is released during the daytime. Without this, the space 39 between the narrow abutment and the existing bridge can be expanded in a short time to secure a space 39 for a worker to enter. The space to be secured has a height of 1000 mm or more, a width of 500 mm or more when only a person enters, and a maintenance management work of preferably 1000 mm or more, more preferably 1500 mm or more and 2500 mm or less. By utilizing this inspection / investigation and repair / reinforcement space 39, it is possible to inspect and repair bridge ends that have been impossible to maintain even if they have been severely deteriorated, and extend the service period of the bridge. can do.

In the above embodiment, the new chest wall 20 has been described as having a shape similar to an inverted T shape, but other shapes shown in FIGS. 19 to 22 can be applied.
In FIG. 19, the cross-sectional shape of the new chest wall 20 is added to an inverted T shape, and a top wall 20b is provided at the upper end in parallel with the bottom wall 20a. When comprised in this way, when the new delivery plate 26 is mounted on the top wall 20b, it can hold | maintain stably.
20 to 21 show an embodiment in which the cross-sectional shape of the new chest wall 20 is formed in a substantially U shape. In the present embodiment, the U-shaped portion can be used as a space 39 for inspection / inspection and repair / reinforcement. In the example shown in FIG. 21, the new chest wall 20 is placed directly on the abutment. In the example shown in FIG. 22, the new delivery plate 26 can be connected to the top wall 20 b of the new chest wall 20.

  Furthermore, the present invention is not limited to the above-described embodiments, and various design changes can be made based on the description of the scope of claims.

10 Improvement method of abutment chest wall 11 Pavement 12 Foot plate 13 Support block 14 Abutment chest wall (existing chest wall)
DESCRIPTION OF SYMBOLS 15 Temporary delivery plate 16 Traffic securing process 17 Excavation process 18 Chest wall installation process 19 Existing chest wall removal process 20 New chest wall 20a Bottom wall 20b Top wall 21 Excavation range 22 Backfill process 23 Ground collapse prevention plate 25 Expansion device 26 New delivery plate 27 Road surface Restoration process 28 Retracting device holder 29 New chest wall support plate 30 Ground improvement process 31 Ground improvement soil 32 Wall railing / roadside belt 33 Median strip / roadside belt 34 Driving lane 35 Passing lane 36 New chest wall fixture 37 Existing abutment wing 38 For connection PC steel 39 Inspection / inspection and repair / reinforcement space 40 Telescopic device installation process

Claims (6)

An excavation process for excavating the back of the existing chest wall when traffic is interrupted;
An existing chest wall removing step of demolishing the existing chest wall;
A chest wall installation step of installing a new chest wall at a position retreated from the position of the existing chest wall in the range excavated in the excavation step, and securing a space between the bridge end and the chest wall;
After installing the new chest wall in the chest wall installation step, a backfilling step of backfilling the area excavated on the back of the new chest wall;
A telescopic device receiver is installed at the end of the bridge, and a new delivery plate is installed on the chest wall, and an expansion device is installed between the telescopic device receiver and the new delivery plate, and is re-mounted on the new delivery plate. Road surface restoration process to restore the road surface, such as paving and route restoration,
A method for improving the abutment chest wall characterized by comprising: Prior to the excavation process, part of the existing road was removed from the pavement and stepping plates, and a support block was installed on the removed road, and a temporary transfer plate was installed between the support block and the abutment chest wall to secure traffic. With a traffic securing process
The method for improving an abutment chest wall according to claim 1, wherein after the temporary transfer plate is removed at the time of traffic interruption in the excavation process, the back soil of the existing chest wall is excavated.   The improvement method of the abutment part chest wall according to claim 1 or 2, wherein the new chest wall in the chest wall installation step is a precast member manufactured in advance.   The method for improving an abutment chest wall according to any one of claims 1 to 3, wherein a cross-section of the new chest wall in the chest wall installation step has a shape similar to an inverted T-shape.   5. The improvement method for an abutment chest wall according to claim 1, wherein, in the backfilling step, the backfilling material uses an improved soil in which soil, cement, water, and the like are mixed. In the road surface restoration step , the telescopic device is installed at a position away from the bridge girder end so that it does not leak directly at the bridge girder end even if there is a possibility of water leakage due to aging of the telescopic device. The improvement method of the abutment part chest wall of any one of Claims 1-5.

Images