JPH03202508A - Slope surface reinforcing earth construction using band-shaped stiffener - Google Patents

Abstract

PURPOSE:To improve the efficiency of the execution of work by inserting band- shaped stiffeners with specified widths and thicknesses, into ground from a natural ground slope surface, to be arranged, and by anchor the base ends of the band-shaped stiffeners on the slope surface. CONSTITUTION:The band-shaped stiffener 1 of a steel plate or the like is used, and the thickness (t) of the plate is set to be 0.6-20mm, and specially preferably, the plate of 1-10mm is used, and the width W is set to be 50mm or more, and sometimes, 100mm or more is set, and the upper limit is set to be 300mm. Besides, in some case, the width W is set to be up to 1000mm, and the length is set to be about 10m at maximum under a condition that work is executed on a slope surface. After that, the band-shaped stiffener 1 is deeply inserted across a forecast slide line l through the slope surface of cutting natural ground 2 and is set, and after the completion of the setting, the slope surface is sprayed with mortar, and a protective wall 3 is formed. Then, the base end of the band- shaped stiffener 1 is tent to the slope surface and is integrated with the protective wall 3, anchor plate 4 is set, and a wedge 5 is driven. As a result, reinforcing effect can be enhanced.

Description

[Detailed Description of the Invention] [Industrial Applications] The present invention is directed to a slope that is stabilized by inserting and installing a band-shaped sleeve from a natural mountain slope, a cut slope, or an embankment slope. Regarding reinforced earth construction methods.

[Conventional technology]

Reinforced earthwork methods are aimed at stabilizing slopes and increasing their bearing capacity. In this case, in the case of reinforcement of the embankment body and in the case of natural ground (
It can also be divided into cases of reinforcing cut slopes (hereinafter referred to as natural ground unless otherwise specified).

A typical example of the former method of reinforcing embankments is the Terre Almée method, in which steel bars or steel plates are installed horizontally at each level of embankment. In addition, when reinforcing the embankment, there are cases where only reinforcement materials such as net materials are used, and cases where a retaining wall is provided as in the case of the Terre Armae method.

On the other hand, the only methods available for natural ground are the method of inserting reinforcing bars in parallel and the method of inserting reticulated reinforcing bars so that they are not parallel to each other.Both methods involve inserting reinforcing bars after drilling into the ground. Fill mortar around the shiso for about 10 minutes.
It forms a small diameter resistor around 0 opening. Note that in the former case, filling with mortar may not be performed.

[Problem that the invention seeks to solve]

However, conventional earthwork reinforcement methods for natural ground use reinforcing bars or small-diameter steel bars containing reinforcing bars to act as resistors against bending moments and shearing, thereby achieving reinforcement. Therefore, for this purpose, it is necessary to install a large number of reinforcing materials in the natural ground, and therefore, a great deal of effort is required as a whole for post-processing such as inserting the reinforcing materials and injecting and fixing the grout.

In addition, the present inventors have discovered that in many cases it is effective to use reinforcing materials as tensile resistors to prevent the collapse of natural lands; However, the present invention focuses on significantly increasing the tensile effect.

Therefore, the main object of the present invention is to provide a reinforced earth construction method that has a large reinforcement effect on the ground and has high construction efficiency.

[Means for solving problems]

The first invention to solve the above-mentioned problems is to insert and install a band-shaped reinforcing material with a thickness of 0.6 to 2 (Jam) into the ground from the ground slope, and to It is characterized in that the base end is fixed to the slope surface.

In addition, the second invention provides at least one of the methods of pressing and striking the rear end of the casing when the slope of the ground is detected, with the reinforcing material having a thickness of 0.6 to 20 mm inserted into the hollow flat casing. After the casing is inserted into the ground, only the casing is pulled out, the reinforcing strip is left in the ground, and the reinforcing strip is fixed on the surface of the slope.

(Function) In the present invention, in order to insert and install the belt-shaped reinforcing material into the ground,
Since the surface area of each material is large, the tensile resistance when the ground tries to collapse is extremely large, and the reinforcing effect of the ground is large.Conversely, because the reinforcing effect is large, it is possible to insert and install fewer strip reinforcements. is sufficient, and the construction man-hours are reduced overall.

On the other hand, the second invention Teja, JrJb 0.6 to 20 mm
(7) Although it is impossible to install thin strip reinforcing materials by press-fitting or hammering, it is impossible to arrange them side by side due to strength. If the strip-shaped reinforcing material is pulled out and left in the ground, even if the reinforcing strip is thin, the casing will prevent the reinforcing strip from deforming, and it can be easily inserted into the ground.

〔Example〕

The present invention will be explained in more detail below with reference to the drawings.

In the present invention, as shown in FIG. Use ili strong shrine. In this case, the thickness t is 0
．． A width W of 6 to 201 mm, particularly preferably 1 to 10 mm, is used, and a width W of 50 mm or more, especially 100 m11 or more is used, and the upper limit is 300 mm, and in some cases 1 mm.
It is said to be up to 0100O. Various lengths can be used, but the longest length is about 10 m due to ease of construction and restrictions on installation equipment due to construction being carried out on a slope.

As shown in FIG. 1, the strip-shaped reinforcing material 1 is inserted and installed to a depth deeper than the depth vAIt expected from the slope of the cut natural ground 2, as shown in FIG. 1, according to an example of insertion and installation described later.

When constructing a pseudo-retaining wall, it is not necessary to reach l.
After this insertion and installation is completed, the protective wall 3 is formed on the slope by spraying mortar or the like, and the base end of the band-shaped reinforcing material 1 is fixed to the slope.

Various methods can be used to fix this, but
For example, as shown in Fig. 4, the base end of the reinforcing material l is folded or folded back as shown in Fig. 5 to integrate it with the protective wall 3, or as shown in Fig. 6, Fixing plate 4 on top of 3
It can be fixed by providing a wedge 5 and driving in the wedge 5.

On the other hand, the reinforcing material 1 may be inserted diagonally, but it is usually preferable to insert it horizontally. Examples of the arrangement include a staggered arrangement as shown in Fig. 3, as well as a layered arrangement in the height direction.If necessary, the conventional method of inserting reinforcing bars with a circular cross section of 6 may be used in combination. The horizontal spacing P of the reinforcing material is 0.5
m to 2 m is preferable, and the height interval is 0.5 to 3 m
is preferred.

On the other hand, when installing reinforcing materials, it is preferable to use press-fitting and/or hammering for convenience; in this case,
Since the reinforcing material 1 is thin and has no yield strength during insertion, it is preferable to press-fit it using a casing as shown in FIGS. 7 to 9.

To explain this, a guide cell 10 is fixed to a scaffold (not shown) or the like outside the slope of the ground, and an air or hydraulic hammer 11 such as a Buehler type or Kurutsub type that advances and retreats in the long plane direction is installed on the guide cell 10. In addition, a reinforcing strip is inserted into the flat rectangular casing 12 having the storage hole 12a, and a wide chevron-shaped tip shoe 13 is placed at the tip of the casing 12. Furthermore, the casing 12
The proximal end of the hammer 110 is detachably connected to the base end of the hammer 110 via a connecting bracket 14.

Using such a press-fitting and impact insertion machine, the reinforcing material 1 is inserted into the casing 12 in advance, and the reinforcing material 1 is
The casing 12 is connected to the recasing 12 by a removable pin 15 at the base of the casing 12, and the casing 12 has a tip shoe 13 and a recess 1 at the rear.
3a, and then attach the tip of the reinforcing material 1 to the tip shoe 1.
With the connecting protrusion 13b of No. 3 connected by the connecting pin 16, the hammer 11 applies hammer force to the proximal end of the casing 12, and the hammer 11 is advanced along the guide cell IO to press-fit it to a predetermined depth. After that, remove the removable bottle 15 and insert the hammer 11 into the guide cell l.
0, and pull out the casing 12, leaving the reinforcing material 1 and the tip shoe 13 in the ground.

Injecting grout into the insertion hole of the reinforcing material 1 increases adhesion to the ground, so in the embodiment, the injection pipe 17 is connected to the inside of the casing 12.

According to this embodiment, after the insertion and installation of the casing 12, the reinforcing material 1, and the tip shoe 13 are completed, grout G is supplied from outside the slope to the injection tube 17, guided into the storage hole 12a, and injected from the tip opening thereof.

This injection work is preferably carried out during the process of drawing out the casing 12, but it may also be carried out while the casing 12, which is about to be drawn out, is facing the hole caused by the drawing.
The grout G may be injected by inserting a separate injection hose into the hole from which the casing is pulled out, without attaching an injection pipe to the casing 12.

Press-fitting is possible even if the tip shoe 13 is not used in the above example and the tip of the casing is left blind or tapered, but as in the example, the width of the base end is thicker than the thickness of the reinforcing material 1. When the tip shoe 13 is used, as shown in Fig. 10, it acts as a resistor for the band-shaped reinforcing material 1 when the ground is about to collapse, and together with the injection effect of the grout G,
A strong tensile resistor can be constructed.

In addition to steel plates, the belt-shaped reinforcing material in the present invention may include other metal plates, striped metal plates with irregularities formed on the surface to increase adhesion, synthetic resin plates, nets, punched metal, or other metal plates. Composite plates with surface treatments such as plating to improve corrosion resistance can be used.

[Experiment example]

Next, we will explain the experimental process by which the inventors came to the knowledge that inserting and installing the strip-shaped reinforcing material according to the present invention into the ground has a superior reinforcing effect than installing reinforcing bars in the conventional example. do.

(Experimental Equipment) Assuming the collapse of a natural rock, a large-scale surface shearing machine shown in FIGS. 11 and 12 was prepared. This shearing machine has upper and lower shearing boxes Bu, B1 with a height of 1.0 cm, a width of 1.5 m and a length of -2,0-, respectively, and a lower shearing box BI.
L is fixed to the base, the upper shear box Bu is moved at a speed of 1 m/min by a 300 ton hydraulic jack 50, fill cement is filled inside the lower shear box Bl, waits for 2 days for it to harden, and the upper A shearing box Bu is filled with sample sand, and the shearing condition of the reinforcing material embedded in the sand and fill cement is investigated.

Further, since the sample sand inside the upper shearing box Bu bulges out due to shearing, a 60-ton vertical jack 51 is provided to prevent this.

52 is a hydraulic unit.

A strain gauge 53 is installed at a predetermined position on the reinforcing material L, an earth pressure gauge 54, 54 is installed on the inner surface of the upper shear box Bu, a horizontal displacement meter 55 is installed on the outer surface thereof, and a vertical displacement meter is installed on the upper restraining lid. A total of 56 are installed, and their signals are analyzed by an arithmetic processing unit 57. 58
is the oil pressure gauge.

The reinforcing materials used in the experiment were reinforcing bars with a diameter of 13 and a diameter of 19+n, and a steel plate with a thickness of 0.611. Regarding reinforcing bars, the combinations shown in Table 1 show how the shearing conditions change depending on their diameter, number, and the presence or absence of filling mortar, and the arrangement in the shear box is shown in Figures 13 (a) to ( It was set as el.

In addition, a total of 14 strain gauges were installed, with seven axially symmetrical strain gauges arranged at equal intervals along the length of each reinforcing bar.

On the other hand, a total of 42 plates were attached to the 0.61 m thick iron plate PL in the arrangement shown in FIG. Pjl is a dummy iron plate of the same thickness. The total cross-sectional area of the iron plate PL is the same as the total surface area of the reinforcing bars of 19+nφ.

(Results) Using the above test machine, the upper shear box was displaced by a 300-ton jab until 20 pieces were displaced.

Figure 15 shows the displacement of the 13Dφ reinforcing bar.

Furthermore, for the bending strain in the case shown in Table 1, the increase in the vertical component due to friction on the circumferential surface of the reinforcing material, the bending stress on the shear plane, and the reinforcement ratio as an index of reinforcement hardening are shown. Figure 17 shows the case of an iron plate.

Here, the reinforcement ratio is the ratio of the shear stress of the reinforced ground to the shear stress of the unreinforced ground that occurs during the same shear strain, and the higher the reinforcement ratio, the higher the reinforcement hardening.

(Decision) In Figure 16, the shear strength is approximately 1.1 in the case of reinforcing bars only.
The strength increases by approximately 163 times when the material is filled with mortar.

On the other hand, if we pay attention to Fig. 17, the intensity ratio is 1.7.
It was found that the strip-shaped reinforcement material has a high reinforcing effect because it increases the surface area and increases the tensile resistance.

〔Effect of the invention〕

As described above, according to the present invention, advantages such as a high reinforcement effect on the ground and excellent construction efficiency are brought about.

[Brief explanation of drawings]

Figure 1 is an overall view of the implementation state of the construction method of the present invention, Figure 2 is a perspective view of the band-shaped reinforcement, Figure 3 is a side view of its arrangement, and Figures 4 to 6.
The figure is a fixation side view of the reinforcing material head, FIG. 7 is a perspective view of an example of the reinforcing material insertion device, FIG. 8 is a perspective view of only the casing in a pulled out state, and FIG. 9 is a state of connection between the tip shoe and the strip-shaped reinforcing material. Figure, 1st
Figure 0 is an overview of the factors in the state in which reinforcing strips are inserted into the ground and grout is injected, Figure 11 is a perspective view of the large-scale front cutting machine used in the experiment, Figure 12 is its overall schematic diagram, and Figure 13. FIG. 14 is a diagram of strain gauge attachment B, FIG. 15 is a diagram of reinforcing bar displacement due to shearing, and FIGS. 16 and 17 are graphs of reinforcing effects by reinforcing bars and iron plates. 1... Belt-shaped reinforcement material, 2... Earth, 3... Protection wall,
6...Reinforcement bar, 10...Guide cell, 11...Hammer 12...Casing, 13...Tip shoe
17... Injection pipe, G... Grout.

Claims (2)

[Claims] (1) Width 50mm or more, thickness 0.6-2 from the mountain slope
In addition to inserting and installing 0mm strip reinforcing material into the ground,
A slope reinforcement earthwork method using a band-shaped reinforcing material, characterized in that the base end of the band-shaped reinforcing material is fixed to the slope surface. (2) Thickness of 0.6 to 20 mm inside the hollow flat casing
With the strip-shaped reinforcing material of 1.5 mm thick inserted, the rear end of the casing is inserted into the ground by at least one of pressing and striking, after the slope of the ground is known, and only the casing is pulled out, leaving the strip-shaped reinforcing material in the ground; A slope reinforcement earthwork method using a band-shaped reinforcing material, which is characterized by fixing this band-shaped reinforcing material to the slope surface.