JP5830068B2 - Slope reinforcement method - Google Patents

Description

  The present invention relates to a slope reinforcing method for constructing a prestressed concrete wall having a very excellent earthquake resistance and fracture resistance on a slope.

As a conventional slope reinforcement method, for example, a reinforcement earth method such as a cut slope as shown in Japanese Patent No. 2530565 is known (see Patent Document 1). This construction method is performed according to the following construction procedure.
(A) forming a step portion excavating a mounting surface on which the first stage concrete precast plate can be installed downward from the upper end of the reinforced soil surface to be formed;
(B) fixing a mounting table for arranging the precast plates in parallel on the stepped portion on the mounting surface side;
(C) A precast plate is placed in parallel on the mounting table with a spacer interposed between the mounting surface side and
(D) After drilling from the mounting hole formed in each precast plate to the mounting surface side and inserting a rod-shaped reinforcing material from the mounting hole into the drilled portion, mortar is placed in the gap between the drilled portion and the precast plate. Inject,
(E) The protruding end portion of each reinforcing member is fixed to the mounting hole and integrally connected to the precast plate,
(F) After drying the mortar, remove the mounting table, and form a step portion excavating the mounting surface on which the concrete precast plate can be installed in the second step from the top,
(G) A second-stage precast plate is suspended from the lower end of each first-stage precast plate, and a spacer is interposed between the mounting surface side,
(H) After drilling from the mounting hole formed in the second-stage precast plate and inserting the rod-shaped reinforcing material from the mounting hole into the drilled portion, the hole is formed in the gap between the drilled portion and the second-stage precast plate. Injecting mortar,
(I) The protruding end of each bar-shaped reinforcing member is fixed to the mounting hole and integrally connected to the second-stage precast plate,
(J) By repeating these procedures, a reinforced soil surface provided with a plurality of precast plates is formed.

  Since the reinforced earth method such as the cut slope of such construction procedure is a construction in which precast plates are installed simultaneously with the earth retaining from the upper part, the occupied land width can be reduced and the amount of earth work can be reduced. Further, since the lower precast plate is suspended and temporarily fixed, there is an advantage that the construction period can be shortened and simplified.

Japanese Patent No. 2530565

  In the conventional earth reinforcement method such as the cut slope of the conventional example, since the precast plates are not integrally connected and fixed, the head of the rod-shaped reinforcement inserted through the mounting hole is corroded or the rod-shaped reinforcement is used. When the material breaks, there is a problem that the precast plate may drop off.

  Similarly, since the precast plates are not integrally connected and fixed, the movement of the precast plates does not synchronize with the slope during the earthquake, and each of them moves apart, resulting in poor earthquake resistance. Has a point.

  Therefore, in the reinforced earth method such as the cut slope in the conventional example, the precast plates disposed on the slope are integrally connected and fixed to prevent the precast plates from falling off, and the earthquake resistance is improved. It has a problem that must be solved.

  The gist of the present invention for solving the problems of the conventional example is that a precast concrete plate is used in which a PC steel material is inserted into the insertion hole in the vertical direction and the insertion horizontal hole for inserting the PC steel material in the lateral direction. A pre-stressed concrete wall is constructed by sequentially arranging the precast concrete plates from the top to the bottom of the slope to construct a prestressed concrete wall. For leveling in a step of leveling after excavating to a predetermined slope, a step of arranging the precast concrete plates in parallel through a back spacer on the leveled slope, and a through hole of the precast concrete plates arranged in parallel A step of inserting a PC steel material, a step of injecting a backing material into the gap between the precast concrete plate and the slope, and the precast concrete Excavating the slope from a central hole provided in the plate, forming a drilling hole, inserting a reinforcing bar after inserting the reinforcing bar into the drilling hole, and fixing the end of the reinforcing bar. And the step of connecting the precast concrete plate and the step of applying compressive force between the precast concrete plates arranged in parallel by tensioning the PC steel material for lateral fastening, While repeating each process continuously and performing the process of placing the precast concrete plate on the slope, connecting the PC steel material of the precast concrete plate and the PC steel material of the precast concrete plate located in the upper stage And having a step of applying a compressive force between the precast concrete plates in the vertical direction by tensioning.

The reinforcing reinforcing bar is a spiral reinforcing bar;
When the precast concrete plates are arranged side by side, the precast concrete plates arranged at the end portions are formed with recesses for tension work in the vicinity of the end portions of the insertion lateral holes;
Is included.

According to the slope reinforcing method according to the present invention, a precast concrete is applied to a precast concrete plate in which PC steel wires (PC steel) for lateral fastening are tensioned and arranged in parallel to each other, and further positioned in an upper stage and a lower stage. Tension is applied after compressing the PC steel bars (PC steel materials) between the plates, so that prestress is introduced between the precast concrete plates. High prestressed concrete walls are built on the slope.
Moreover, since the precast concrete plates are integrally connected and fixed in the lateral direction and the vertical direction, even if the head of the reinforcing steel bar corrodes or the reinforcing steel bar breaks, the precast concrete plate can be prevented from falling off. There are various excellent effects.

  Since the reinforcing bar is a spiral reinforcing bar, it has an excellent effect that it has good adhesion to the ground and can be integrated, and the occurrence of cracks in the vicinity of the reinforcing bar can be prevented.

  When the precast concrete plates are arranged in parallel, the precast concrete plates arranged at the end portion are formed of a concave portion for tension work in the vicinity of the end portion of the insertion horizontal hole. There is an excellent effect that the tension work can be performed efficiently.

It is explanatory drawing which shows the state which excavates the slope 12 which arrange | positions the 1st-stage precast concrete board 11 to a predetermined gradient. (A) It is a front view of the precast concrete board 11. FIG. (B) It is a front view of the precast concrete board 11L. (C) It is a front view of the precast concrete board 11R. It is explanatory drawing which shows the state which arrange | positions the precast concrete board 11 on the slope 12. It is a front view which shows the state which arranged the precast concrete board 11 and 11R along the slope 12 in parallel. It is a front view which shows the state which inserts the PC steel wire 47 for horizontal fastening into the insertion horizontal hole 45 of the precast concrete board 11L, 11, 11R arrange | positioned in parallel. It is explanatory drawing which shows the state which inject | pours the grout 30 in the clearance gap 24 of the precast concrete board 11 and the slope 12. FIG. It is explanatory drawing which shows the state which excavates the slope 12 with the drilling machine 27, and forms the excavation hole 28. FIG. It is explanatory drawing which shows the state which inserted the reinforcing bar 29 in the excavation hole 28, and inject | poured the grout 32. FIG. It is explanatory drawing which shows the state which fixes the edge part 29a of the reinforcing steel bar 29, and connects with the precast concrete board 11. FIG. It is a front view which shows the state which applies compression force to the precast concrete board 11L, 11, 11R. It is explanatory drawing which expands and shows the adjacent part which made 2 units of precast concrete boards 11 and 11 adjoin. It is explanatory drawing which shows the state which excavates the slope 12 which arrange | positions the 2nd-stage precast concrete board 11 to a predetermined | prescribed gradient. Explanatory drawing which shows the state which connects the PC steel bar 19a of the 2nd-stage precast concrete board 11a, and the PC steel bar 19 of the precast concrete board 11 located in an upper stage, and is tensioned with the torque wrench 34 and applies compression force. It is. It is sectional drawing which shows the prestressed concrete wall 52 which PC steel bar 19, 19a, 19b connected.

  Next, the slope reinforcing method of the present invention will be described with reference to the drawings. First, as shown in FIG. 1, the uppermost stage of the slope 12 where the precast concrete plate 11 is arranged is excavated by one stage to a predetermined gradient by operating the backhoe 13. The height of one step is preferably about 1.3 m in consideration of the height of the precast concrete plate 11 (about 1 m) and the height of the temporary foundation 14.

  Then, after leveling the unevenness of the slope 12, the spread sand 15 is disposed, the temporary foundation 14 is installed on the top, and the back surface drainage material 21 is installed. In addition, the code | symbol 16 in FIG. 1 shows the temporary embankment scaffold provided in order for the backhoe 13 etc. to work, and the code | symbol 25 shows a natural ground.

  As shown in FIG. 2 (a), the precast concrete plate 11 is formed in a rectangular shape. As an example of the size, the height is about 1000 mm, the width is about 2000 mm, Is about 300 mm. A central hole 17 is provided in the center, and insertion holes 18 and 18 are formed along the vertical direction at positions near both ends. A PC steel rod (PC steel material) 19 is inserted into the insertion hole 18 (see FIGS. 13 and 14). Further, insertion lateral holes 45, 45 are formed along the lateral direction at positions near both the upper and lower ends. The insertion horizontal hole 45 is a hole for inserting a PC steel wire (PC steel material) 47.

  The precast concrete plate 11L shown in FIG. 2 (b) is for placement at the left end of a plurality of precast concrete plates arranged in parallel. In the vicinity of the left end of the insertion horizontal hole 45, tension work is performed. A recess 46L is formed (see FIG. 10). Other dimensions and shapes are substantially the same as those of the precast concrete plate 11.

  Similarly, the precast concrete plate 11R shown in FIG. 2 (c) is for placement at the right end of a plurality of precast concrete plates arranged in parallel. In the vicinity of the right end of the insertion horizontal hole 45, A recess 46R for performing a tensioning work is formed (see FIG. 10). Other dimensions and shapes are substantially the same as those of the precast concrete plate 11.

  Next, as shown in FIG. 3, the precast concrete plate 11 is lifted by the crane 20 and placed on the upper portion of the temporary foundation 14 and arranged in parallel along the slope 12 (see FIG. 4). At this time, a wedge-shaped camber 22 is interposed above the temporary foundation 14. Further, a predetermined gap 24 is provided between the slope 12 and the precast concrete plate 11 with a back spacer 23 interposed (see FIG. 3).

  In addition, since it is a reverse winding construction in which construction is performed sequentially from the upper stage to the lower stage, when placing the precast concrete plate 11 on the uppermost stage, an adjustment plate (not shown) is accurately installed by surveying, resulting in misalignment, etc. There is no need to do so.

  In addition, the precast concrete plates 11L, 11, 11,..., 11R arranged in parallel in the lateral direction (see FIGS. 4, 5, and 10) are about 10 in total, that is, 20 m (10 sheets × width 2000 mm = 20 m). It is desirable to arrange as one unit. If necessary, a plurality of units are arranged in parallel so as to be adjacent to each other.

  Next, as shown in FIG. 5, the laterally tightening is performed in the insertion horizontal holes 45, 45, 45 (not shown in FIG. 5) of the precast concrete plates 11 </ b> L, 11, 11, 11 </ b> R arranged in parallel. PC steel wire 47 is inserted.

  Then, as shown in FIG. 6, a backing material (grouting) 30 is injected into the gap 24 between the precast concrete plate 11 and the slope 12. Reference numeral 26 in FIG. 6 indicates an injection hose for injecting the backing material 30.

  Next, as shown in FIG. 7, the drilling machine 27 is operated to excavate the slope 12 from the central hole 17 provided in the precast concrete plate 11 to a predetermined depth to form a drilling hole 28.

  Further, after inserting the reinforcing reinforcing bar 29 into the excavation hole 28, the grout 32 is injected as shown in FIG. Reference numeral 48 in FIG. 8 indicates an injection hose for injecting the grout 32.

  The reinforcing reinforcing bar 29 is preferably a spiral reinforcing bar formed by spirally winding a reinforcing bar. In this case, the adhesion to the ground is good and integration is achieved, and the occurrence of cracks in the vicinity of the reinforcing steel bars 29 can be prevented.

  After the grout 32 is hardened, as shown in FIG. 9, the end 29 a of the reinforcing reinforcing bar 29 is fixed and connected to the precast concrete plate 11 using a torque wrench (not shown). Then, the cap plate 31 is attached to the end 29 a of the reinforcing reinforcing bar 29.

  Furthermore, as shown in FIG. 10, in the recess 46L (or 46R) of the precast concrete plate 11L (or 11R), the side fastening jack 49 is used to tension the PC steel wire PC steel wire 47 for side fastening, and the parallel A compressive force is applied to the precast concrete plates 11L, 11, 11,.

  In addition, FIG. 11 is explanatory drawing which expanded and showed the recessed part 46R and the recessed part 46L of the adjacent part at the time of making two units of precast concrete boards adjoin. The PC steel material 47 for lateral fastening is tensioned by installing a plate 49 and a nut-type clip 50, and the PC steel materials 47 and 47 are connected to each other via a coupler 51.

  Each of the steps described above (see FIGS. 1 to 10) is performed, and a plurality of precast concrete plates 11L, 11, 11,..., 11R are arranged in parallel, so that the precast concrete plate 11L, 11, 11... 11R are installed, and the PC steel wire 47 for lateral fastening is tensioned to apply a compression force.

  Each of these steps is repeated again and briefly described as follows. The step of excavating the uppermost step of the slope 12 on which the precast concrete plate 11 is arranged to a predetermined slope and then leveling the ground (see FIG. 1), and the precast concrete plate 11 are arranged in parallel via the spacer 23 on the leveled slope 12 (See FIG. 3), a step of inserting a PC steel material 47 for lateral fastening into the insertion horizontal holes 45 of the precast concrete plates 11L, 11, 11,..., 11R arranged in parallel (see FIG. 5), a precast concrete plate Injecting grout 30 into the gaps between 11L, 11, 11R and slope 12 (see FIG. 6), excavating slope 12 from center hole 17 provided in precast concrete plates 11L, 11, 11R to a predetermined depth A step of forming the excavation hole 28 (see FIG. 7), a step of injecting the grout 32 after inserting the reinforcing bar 29 into the excavation hole 28 (FIG. 8). ), Fixing the end 29a of the reinforcing reinforcing bar 29 and connecting it to the precast concrete plate 11 (see FIG. 9), precast concrete plates 11L, 11 in which the PC steel material 47 for lateral fastening is arranged in parallel in tension. 11 ..., 11R, and a process of applying a compression force to each other (see FIG. 10).

  Next, the construction of the precast concrete plate 11a after the second stage is carried out by repeating the above steps continuously, such as excavation of the slope 12 (see FIG. 12) by operating the backhoe 13, and will be described later. A step of connecting the PC steel bars 19, 19a is added. That is, when placing the second and subsequent precast concrete plates 11a on the slope 12, as shown in FIG. 13, a PC steel bar 19a inserted into the precast concrete plate 11a and a precast concrete plate located on the upper step. After connecting the PC steel rod 19 inserted into the plate 11, it is tensioned to apply a compressive force.

  The process shown in FIG. 13 will be described in detail. First, the second-stage (lower) precast concrete board 11a is lifted by the crane 20 and placed on the lower side of the precast concrete board 11 located on the upper stage. And the end part of PC steel bar 19 of the precast concrete board 11 located in the upper stage and PC steel bar 19a of the precast concrete board 11a of the 2nd stage (lower stage) are connected with a coupler 35.

  After connecting the PC steel bars 19 and 19a, the second-stage (lower) precast concrete plate 11a is pulled up to a predetermined position and installed. Next, an anchor plate, a washer, and a coupler 35 (not shown) are attached to the lower end of the PC steel bar 19a, and the torque wrench 34 is used for tension. At this time, it is necessary to accurately fix and install the precast concrete plate 11a while confirming the position and gradient of the precast concrete plate 11a. Arrangement of the precast concrete plates 11b... In the third and subsequent stages is also performed by sequentially repeating the connection of the PC steel bars and the tension work in the same manner as described above.

  In this way, since the PC steel bars 19 and 19a are coupled with each other by the coupler 35 and are tensioned to apply a compressive force, the precast concrete plates 11 and 11a disposed on the slope 12 are integrally coupled and fixed. As a result, the earthquake resistance is greatly improved. Moreover, since the coupler 35 is used for the connection between the PC steel bars 19 and 19a, the connection state is strong and reliable.

  FIG. 14 shows the slope 12 on which the precast concrete plates 11, 11a, 11b are arranged in such a construction procedure. The PC steel bars 19, 19a, 19b are connected to each other by a coupler 35. Moreover, the top end concrete 36 is provided in the upper end part, and the coupler protective cap 37 and the volt | bolt 38 are attached. Furthermore, a lower concrete 39 is provided at the lower end, and a coupler protective cap 37 and a bolt 38 are attached. In addition, the code | symbol 40 shows the auxiliary steel plate for adjustment, and the code | symbol 41 shows a polystyrene foam.

  As described above, according to the slope reinforcing method according to the present invention, the PC steel wire 47 for side fastening is tensioned, and the precast concrete plates 11L, 11, 11,. In addition (see FIG. 10), since the precast concrete plates 11 and 11a located at the upper and lower stages are connected to each other and the PC steel bars 19 and 19a are connected to each other, the tension is applied and the compressive force is applied (see FIG. 13). Prestress is introduced between the columns of the precast concrete plates 11, 11L, 11R, 11a, and 11b. As a result, the prestressed concrete wall 52 having excellent earthquake resistance and high puncture resistance is constructed on the slope 12. It will be.

11, 11L, 11R, 11a, 11b Precast concrete plate 12 Slope 13 Backhoe 14 Temporary foundation 15 Laying sand 16 Temporary embankment 17 Central hole 18 Insertion hole 19, 19a, 19b PC steel bar (PC steel)
DESCRIPTION OF SYMBOLS 20 Crane 21 Back surface drainage material 22 Camber 23 Backing spacer 24 Clearance 25 Ground mountain 26 Injection hose 27 Drilling machine 28 Drilling hole 29 Reinforcing bar 29a End 30 Backing material (grouting)
31 Cap Plate 32 Grout 33 Drainage Material 34 Torque Wrench 35 Coupler 36 Top End Concrete 37 Coupler Protection Cap 38 Bolt 39 Lower Concrete 40 Supplementary Steel Plate for Adjustment 41 Styrofoam 42 Concave Parts 43 Convex Parts 44 Coupling Plates 45 Insertion Horizontal Holes 46L, 46R Concave Parts 47 PC steel wire (PC steel)
48 Injection hose 49 Plate 50 Nut clip 51 Coupler 52 Prestressed concrete wall

Claims (2)

PC steel material is installed in the insertion hole in the vertical direction, and a precast concrete plate having an insertion horizontal hole for inserting the PC steel material in the horizontal direction is used, and the precast concrete plate is moved from the uppermost stage to the lower stage of the slope. It is a slope reinforcement construction method that constructs prestressed concrete walls by arranging them sequentially,
A step of excavating a slope on which the first-stage precast concrete plate is arranged to a predetermined slope and then leveling the ground;
Arranging the precast concrete plates in parallel via a back spacer on the leveled slope;
Inserting a PC steel material for lateral fastening into the insertion lateral hole of the precast concrete plate arranged in parallel;
Injecting a backing material into the gap between the precast concrete plate and the slope,
A step of excavating the slope from a central hole provided in the precast concrete plate to form an excavation hole;
Injecting grout after inserting spiral rebar into the borehole;
Fixing the end of the spiral rebar and connecting to the precast concrete plate;
Applying a compressive force to the precast concrete plate in which the PC steel materials for side fastening are arranged in parallel with tension;
Have
For the second and subsequent stages of construction, the above-mentioned steps for continuously arranging the steps and placing the precast concrete plate on the slope are performed when the precast concrete plate PC steel material and the precast concrete located in the upper step are used. A slope reinforcing method comprising a step of applying a compressive force between precast concrete plates in the vertical direction by connecting the PC steel materials of the plates and then tensioning them. The precast concrete board arranged at the end when the precast concrete boards are arranged in parallel has a recess for tension work formed in the vicinity of the end of the insertion horizontal hole. Slope reinforcement method.

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