JPH01244003A - Lock-shade and construction thereof - Google Patents

Abstract

PURPOSE:To increase rigidity without spoiling a view by projecting a cantilever overhang floor slab from a retaining wall along the face of a slope and holding a protective wall body of precast concrete (PC) by a lock-anchor at the side of the face of slope and by a cast-in place concrete retaining wall. CONSTITUTION:A foundation and cast-in place concrete retaining wall 2 in which an anchor steel bar is buried is constructed. Then, an anchoring PC steel 9 is inserted into an anchor hole 7, and is fixed by anchor concrete 12. After that, a protective cylinder 8 is fitted in the opening of the anchor hole 7, it is closed with a bearing slab 13, and grout mortar is filled between a sheath 11 and the protective cylinder 8. A protective wall body 20 constituted of a supporting point protective section 21 and an overhang floor slab section 22 is so fixed that PC steel bar 30 and PC steel 26 are respectively inserted into insertion holes 23 and 24. In case stones fall on the overhang floor slab section 22, the top of the retaining wall 2 acts as a supporting point, tensile force acts on the PC steel 9 and PC steel 26 coupled therewith, so that is can fear load.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a rock shed for covering a road adjacent to a steep slope such as a road in a mountainous area to catch and stop falling rocks.

(Conventional technology) Conventional rock sheds have been constructed using H-shaped steel or precast concrete (hereinafter referred to as PC), and include protective fence-type structures in which pillars are erected on slopes, and gate-shaped structures with support structures. There are gate-type structures that combine steel beams and beams and whose upper surface is covered with a concrete floor slab, and arch-type structures that have an arch-shaped steel support column whose outer surface is covered with a concrete slab.

(Problem to be solved by the invention) Among these conventional rock sheds, the protective fence type cannot handle large loads when the ground surface is unstable and prone to collapse or is steeply sloped. Roads cannot be protected from large rockfalls.

In addition, gate-type and arch-type types can completely protect the road from large falling rocks and avalanches, but on winding mountain roads, visibility is severely obstructed and the scenery is spoiled. Since the entire area of the building was to be used, and many parts were to be constructed on-site, the construction period was long and the construction costs were high.

In view of these problems, the present invention has been designed to be robust and able to withstand heavy falling rocks, without impairing visibility or scenery unlike gate-shaped or arch-shaped structures, even when the surface of a steep slope or other mountain surface is unstable. The object of the present invention is to provide a lock, a shed, and a method for constructing the same, which can be constructed without the need for long road closures.

In order to solve the above-mentioned conventional problems and achieve the intended purpose, the present invention is characterized by the use of cast-in-place concrete that also serves as a foundation and is constructed vertically along a slope. A protective wall main body made of precast concrete, which integrally has a retaining wall and an overhanging floor slab portion projecting from the front side upper edge of the retaining wall portion for a fulcrum whose lower end is in contact with the top of the retaining wall, and the protective wall main body. and a rock anchor that is fixed to the ground side, and the vertical wall part of the protective wall main body is integrated with the retaining wall with a vertically oriented anchor steel rod, and the rock anchor is opened to the ground surface with the rock anchor attached. A protective tube is fitted into the opening of the anchor hole, and the outer end surface of the protective tube is closed with a bearing plate, and the rock anchor PCg! is attached to the bearing plate. 4. At the same time, a PC steel material insertion sheath is inserted into the protective cylinder, the space between the sheath and the protective cylinder is filled with grout mortar, and the PC@ material for the protective wall body is fixed in the PC@ material for the rock anchor. A rock shed is formed by mechanically anchoring one end and applying prestress to the protective wall body, and a retaining wall that also serves as a foundation is constructed horizontally using cast-in-place concrete along the slope, and the top of the retaining wall is An anchor hole for a rock anchor is drilled in the ground at a higher position, and anchor concrete is poured into the anchor hole. At the same time, an anchor PC steel material is inserted and the inner end of the anchor PC @ material is inserted. Waiting for the anchor concrete to harden, a bearing plate is placed at the opening of the anchor hole, and the protruding end of the anchor PC steel is fixed under tension. A precast concrete protection wall main body having a wall portion and an overhanging floor slab integrally has the lower end surface of the vertical wall abutting the upper end of the retaining wall, and the rear end of the overhanging floor slab portion is brought into contact with the upper end of the retaining wall. After mechanically connecting the end of the PC steel material for the floor slab part inserted through the overhanging floor slab part to the end of the PCS+ material for the anchor in a state temporarily fixed to the bearing plate, the back of the protective wall main body is Place backfill concrete between the ground and the ground, wait for it to harden, then overhang the p c @ material for the deck section, tension it at the tip of the deck section, and fix the end to give prestress. Located in the Rockshed.

(Function) This rock shed receives falling rocks on the overhanging deck section of the protective wall main body, and when external force from falling rocks is applied downward onto the overhanging deck section, the lower end of the retaining wall for the fulcrum becomes the fulcrum. As a result, an external force is applied to the lock anchor in the pulling direction, resulting in high yield strength.

Further, at the end of the rock anchor, the PC steel material is protected by the protective tube and the concrete inside, and shearing force is not directly applied to the PC steel material, resulting in high durability.

Furthermore, the overhanging floor slab part has a continuous P that is connected to the rock anchor.
Because it has a C structure, it has high elasticity against bending moments, and the rock anchor itself is also PC! Since it is curved, high elasticity and proof strength can be obtained in the pulling direction.

In addition, when constructing this rock shed, since the main body of the protective wall is made of precast concrete, high-quality products manufactured under control at a factory can be used, and even in adverse working environments such as temperature and other weather conditions, it is possible to use high-quality materials. You can build a strong rock shed.

Furthermore, when installing the precast concrete protective wall main body, by temporarily fixing it to rock anchors, a stable condition can be immediately obtained, eliminating the need for shoring.

(Example) Next, an example of implementation of the present invention will be described with reference to the drawings.

First, as shown in Fig. 5, a cast-in-place concrete retaining wall 2, which also serves as a foundation, is constructed along the slope of the road surface 1.

An anchor steel rod 3 is buried in this retaining wall 2, and a coupler 4 is attached to its upper end.

Next, a scaffold 5 is erected with one edge supported on the top surface of the retaining wall 2, a hole drilling machine 6 is set on top of the scaffold 5, and an anchor hole 7 is drilled at a required height position on the slope. When drilling this hole, a steel protection tube 8 is embedded in advance in the opening of the anchor hole 7, and the hole is excavated from the inside.

After drilling the hole to a predetermined depth, the anchor PC steel material 9 is inserted. As shown in FIG. 4, this pcH material 9 has a fixing device 10 fixed to its tip to prevent removal, and is inserted into the sheath 11 by a certain length on the protruding end side.

After inserting the PC steel material 9 in this manner, cement milk is injected into the anchor hole 7 without entering the sheath 11 to form the anchor concrete 12.

After pouring the cement milk, the bearing plate 13 is set at the opening of the anchor hole 7. As shown in FIG. 3, one piece of this pressure-bearing plate 13 is placed across two anchor holes 7.7, and a PC steel material insertion hole 14 is provided at a position corresponding to each anchor hole 7.7. It is opened, and the end of the sheath 11 is brought into contact with the back surface of the opening, and the end of the protection tube 8 is fixed to the outside of the contact part of the sheath 11 at a distance. In addition, a temporary fixing protrusion 1, which will be described later, is provided at the center of the front surface of the pressure-bearing plate 13.
5 (shown in FIG. 3) is provided in a protruding manner. Cement milk is then filled all at once into the gap between the protection tube 8 and the sheath 11 through the injection tube 16 shown in FIG.

After filling the cement milk all at once in this way, wait for it to solidify, then tension the PC steel material 9 from the surface side of the bearing plate 13, and fix the end portion to the bearing plate 13 via the fixing fitting 17. Thereafter, grout made of cement milk is injected into the sheath 11 and solidified to form a rock anchor 18 whose outer end is made of PC.

After the formation of this rock anchor 18 is completed, a protective wall main body 20 made of precast concrete is set. This protective wall main body 20 has a block shape in which a supporting wall retaining wall part 21 that is oriented vertically and an overhanging floor slab part 22 that is arranged slightly obliquely from the horizontal are integrally molded in a dogleg-like arrangement. A large number of blocks are arranged in sequence in the horizontal direction to create a continuous overhanging floor slab that overhangs the road. A steel rod insertion hole 23 is opened through the fulcrum retaining wall portion 21 of each block at a position corresponding to the extension of the anchor steel rod 3 of the cast-in-place concrete retaining wall 2 described above, and the overhanging floor slab portion 22 is provided with a steel rod insertion hole 23. Two PC steel material insertion holes 24.24 are opened in the extending direction of the 20g4 anchor material 9, and a plurality of overhanging floor slab portions 22.22 are adjacent to each other in a direction crossing these holes. . . . A PC@material insertion hole 255 for integrating the space is opened.

When installing the protective wall main body 20,
The PC steel material 26 for the plate part is inserted into the PCT material insertion hole 24, and as shown in FIG. The temporary fixing anchor metal fittings 28 which are projected from the bearing plate 13 are fixed with bolts 29 to the temporary fixing protrusions 15 which do not protrude from the bearing plate 13 for temporary installation. In this state, insert the PC steel rod 30 into the steel rod insertion hole 23, screw its tip into the coupler 4 of the anchor PCG4 material 9, tighten it from the upper end with the jack 31, and fix the upper end to the upper end surface. . On the other hand, the PCe inserted into the PC@material insertion hole 24
The end of the material 26 is fixed to the support fitting 17 of the rock anchor 18, the fixed part is covered with a trumpet sheath 32, and this is embedded, and backfilling concrete 32 is cast between the back surface of the protective wall main body 20 and the ground. After this backfilling concrete 37 hardens, the PC steel material 26 is stretched out and the floor slab portion 22
is tensioned by jacks 33 from the leading edge side, fixing the end thereof, and applying prestress in the protruding direction to the overhanging floor slab portion 22. In addition, multiple overhanging floor slab sections 22.22.
Each PC steel material insertion hole 25.25
. . . The PC steel material 34 is inserted through and tensioned to integrate them.

After installing the protective wall main body 20 in this manner, a rising wall 35 is erected on the upper surface of the tip of the overhanging floor slab portion 22, and a fence 36 is placed on top of the rising wall 35, and the overhanging floor slab portion 22 surrounded by the rising wall 35 is erected. Sand 36 for cushioning is placed on top.

In the rock shed constructed in this way, the overhanging floor slab part 22 is made of PC, so even if it is lightweight and thin, it has high elasticity and high strength. In the extension direction of the anchor 18, a fulcrum retaining wall part 21 protrudes integrally below the base of the overhanging floor slab part 22, and this is in contact with the top of the cast-in-place concrete retaining wall 2. If a large downward load is applied to the overhanging floor slab section 22 due to a falling rock, the top of the cast-in-place concrete retaining wall 2 will serve as a fulcrum, and the 20g4 material 9 of the rock anchor 18 and its extension direction will be A tensile force is applied to the PC steel material 26 in the connected overhanging floor slab portion 22, thereby withstanding the rockfall load.

(Effects of the Invention) As described above, the rock shed of the present invention has a structure in which the floor slab protrudes in a cantilevered manner from the retaining wall along the slope, so it does not block the view of passersby and improves the scenery. Moreover, it can withstand heavy loads caused by heavy falling rocks.

In addition, when building horizontally, the main body of the precast concrete protection wall is supported by rock anchors on the slope side and cast-in-place concrete retaining walls, so the road can be closed for less time and the overall construction period is shorter. Moreover, it is possible to construct products with stable quality.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of the completed rock fed state of the present invention.
Fig. 2 is a front view of the same, Fig. 3 is a plan view showing the arrangement of each member, Fig. 4 is an enlarged sectional view of a part of the lock anchor, Fig. 5,
FIG. 6 is a longitudinal sectional view showing different states during construction. 2... Cast-in-place concrete retaining wall, 7...
・Anchor hole, 8...Protective tube, 9...
PC steel material for anchor, 11... Sheath, 12.
... Anchor concrete, 13 ... Bearing plate, 15 ... Protrusion for temporary fixing, 17 ...
・Fixing metal fittings, 18... Lock anchor, 20.
...Protective wall main body, 21 ... Retaining wall section for fulcrum, 22 ... Overhanging floor slab section, 26 ...
PC steel material for floor slab section, 28... Anchor metal fittings for temporary fixing, 32... Backfilling concrete.

Claims (2)

[Claims] (1) A cast-in-place concrete retaining wall that also serves as a foundation and is constructed vertically along the slope, and an overhanging floor that extends from the upper edge of the front side of the supporting retaining wall whose lower end is in contact with the top of the retaining wall. It has a protective wall main body made of precast concrete that integrally has a block part, and a rock anchor that fixes the protective wall main body to the ground side, and the vertical wall part of the protective wall main body is vertically oriented with respect to the retaining wall. At the same time, a protective cylinder is fitted into the opening of the anchor hole opened in the ground surface with the rock anchor, and the outer end surface of the protective cylinder is closed with a bearing plate, and the bearing pressure is P for lock anchor on plate
While fixing the C steel material, insert a sheath for inserting the PC steel material into the protective cylinder, fill the space between the sheath and the protective cylinder with grout mortar, and attach one end of the PC steel material for the protective wall body to the PC steel material for the rock anchor. The lock shed is mechanically fixed and prestressed to the protective wall body. (2) Construct a retaining wall that also serves as a foundation along the slope using cast-in-place concrete, and drill anchor holes for rock anchors in the ground at a position higher than the top of the retaining wall, and insert holes into the anchor holes. While pouring anchor concrete, inserting a PC steel material for anchor and fixing the inner end of the PC steel material for anchor in the anchor concrete,
After waiting for the anchor concrete to harden, a bearing plate is placed at the opening of the anchor hole, the protruding end of the anchor PC steel material is fixed under tension, and then the vertical wall part and the overhanging floor plate part are integrated. A protective wall body made of precast concrete having a vertical wall is brought into contact with the upper end of the retaining wall, and the rear end of the overhanging floor slab is temporarily fixed to the bearing plate. After mechanically connecting the end of the PC steel material for the anchor to the end of the PC steel material for the floor slab inserted through the overhanging floor slab, backfill concrete is poured between the back of the protective wall main body and the ground. After waiting for the solidification, the prestressed PC steel material for the floor slab is stretched out and tensioned at the tip of the floor slab, and the end is fixed to give prestress.