JPS60242223A - Stabilization work for slope by insertion of reinforcement - Google Patents

Abstract

PURPOSE:To prevent the degradation of a slope by a method in which reinforcing materials whose surfaces have a great frictional coefficient with soil are driven into the sloped ground, and the ends of two or more groups of reinforcing materials on the ground surface are pulled to each other for each group. CONSTITUTION:Annular or spiral grooves 7 and 8 or many recessions for example are provided on the surfaces of a reinforcing material 3 to increase the frictional coefficient with soil. Plural reinforcing materials 3 are driven into a slope 1 by leaving their end portions 2 on the ground surface. The materials 3 are divided into at least two or more equal or unequal plural groups, and the end portions 2 on the ground surface of them connected by bars 4 with turnbuckles 5. The turnbuckles 5 are then turned to pull the end portions 2 on the ground surface in such a way as to consolidate the surface layer of the slope by a force F1.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a slope stabilization method that can effectively prevent collapse of a soil slope by inserting a reinforcing material into the slope.

[Conventional technology]

Conventionally, as a construction method to prevent landslides or collapse of soil slopes created by cutting or filling, a method of driving reinforcing materials into soil slopes is known, and the resistance against collapsing soil masses is determined by bending rigidity, shearing stiffness, etc. Strength, Rondo diameter,
Rondo spacing, protrusion length.

Rooting length, depth of the landslide surface, soil properties of the mobile and immobile layers, condition of the soil mass on the back of the rondo, how the landslide soil pressure is applied,
It is thought that it is a function of the state of movement, etc., and although it cannot be generally defined, various calculation formulas have been proposed to simplify these elements in actual construction, and based on the design calculation formula, It is being constructed.

The present applicant also previously disclosed a method for stabilizing slopes by inserting reinforcing materials in JP-A-56-142935.

This construction method involves placing multiple reinforcing materials regularly or irregularly on the soil slope, dividing the reinforcing materials into groups of at least two or more of equal or unequal numbers, and for each group. It is characterized by generating a compaction force on the soil slope by drawing the ground surface ends of the reinforcing members together using a rod-like object or a linear object having a turnbuckle.

Moreover, with this configuration, Coulomb's law (S−C+σ
tanφ where S: shear strength of soil, C: adhesive strength of soil,
By increasing the adhesion of the soil at σ: normal stress applied to soil particles, φ: angle of internal friction of the soil, the shear strength S can also be increased, and soil l' can be prevented.

[Problem that the invention seeks to solve]

However, the slope stabilization method described above has a problem in that there is a limit to the increase in the number of prevention piles, so there is a limit to the increase in shear strength.

The present invention is a method for stabilizing slopes by inserting reinforcing materials, which improves the adhesion of the soil and significantly increases the shear strength of the soil without increasing the number of reinforcing materials inserted, thereby significantly stabilizing the soil slope. The purpose is to provide

[Means for solving problems]

In order to achieve the above object, the present invention not only connects the heads of each reinforcing member, but also shapes the circumferential surface of the underground part to have a large coefficient of friction with the soil. [Function] With the above configuration, The reinforcing material can increase the adhesion of soil not only by compaction caused by tightening the heads together, but also by the shape of the circumferential surface of the reinforcing material itself.

〔Example〕

Hereinafter, the present invention will be specifically described based on embodiments shown in the accompanying drawings.

Figure 1 is a cross-sectional view of a soil slope that has been subjected to the stabilization method according to the present invention, Figure 2 is an explanatory diagram of the action of the reinforcement material on the soil slope, and Figures 3 to 5 are the surrounding areas of the reinforcement material. A partially enlarged explanatory view of the reinforcing material showing the surface shape, and FIGS. 6 to 8 are explanatory views of the arrangement of the reinforcing material.

In Figure 1, (1) is a soil slope, and a plurality of reinforcing materials (3) are placed on the same soil slope (1), leaving its surface edge (2).
has been poured. Also (4) is the ground surface of the reinforcement material (3)!
(It is a rod-shaped object that connects 21 comrades in a tight state, (5
) is a turnbuckle attached to the center of the rod-shaped object (4).

With this configuration, when the turnbuckle (5) is rotated, the ground surface ends of the reinforcement (3) are strongly attracted to each other as shown in FIG. 2, and as a result, as shown in FIG. While the deep part is subjected to the force F2, the surface layer of the slope is consolidated by F, and this consolidation can increase the cohesive force C of the soil.

Furthermore, in the present invention, the shape of the peripheral surface of the reinforcing material (3) is such that the coefficient of friction with the soil is large, that is, the surface area is large, and this shape can also increase the adhesive force of the soil.

The shape of the peripheral surface of the reinforcing material (3) may be any shape as long as it can increase the coefficient of friction with the soil, but examples of preferred shapes are shown in FIGS. 3 to 5.

Figure 3 shows a reinforcing material (3) in which large-diameter annular portions (7) and small-diameter annular portions (8) are provided alternately in a wavy manner in the axial direction, and the reinforcement material (3) has a larger diameter than a reinforcing material (3) of the same diameter. The area of the circumferential surface can be significantly increased.

Figure 4 shows a reinforcing material (3) with a spiral groove (9) on its circumferential surface.
), and the area of the peripheral surface of the reinforcing material (3) can be similarly increased.

Further, FIG. 5 shows a reinforcing material (3) having a large number of protrusions α0) on the circumferential surface, and the area of the circumferential surface can also be increased by such protrusions θO).

With this configuration, in the present invention, the adhesion of the soil can be increased not only by compaction due to the mutual tightening of the heads of the reinforcing material (3), but also by increasing the circumferential surface of the reinforcing material (3), thereby reducing the shearing force. A significant increase and increase in slope stabilization effect can be obtained.

6 to 8 show the arrangement of placing reinforcement (3) on a soil slope (1).

Such an arrangement does not need to be divided into uniform numbers or uniform groups as long as a force is applied to the entire slope in a well-balanced manner.

However, in order to maintain the stability of the entire slope in a well-balanced manner, in the case of a slope with collapsible soil (1), it is necessary to It is preferable to show the distribution of groups every two or three, and as average as possible, but instead of doing so, the configurations in Figures 6, 7, and 8 can be arbitrarily combined. You can also do that.

Further, the present invention can be applied to any soil slope (11 is cut or filled soil, rock with cracks, single layer clay or sandy).

The material of the reinforcing material (3) to be used may be metal, wood, concrete, etc. In addition, to install Anchor Rondo (3), reinforcing material is inserted into a hole drilled in the ground in advance, and cement milk is injected to fix it.
Cement milk can also penetrate into internal cracks and voids deep in the soil to increase integration.

[Experiment example]

An experiment was conducted to examine the relationship between the insertion of reinforcing material and the adhesive force C of the soil and the friction angle φ. The experiment will be explained below.

Figure 9 is a diagram showing the soil particle size test results used in an experiment to investigate the influence of reinforcement materials on soil adhesion and friction angle, and Figures 1O and 11 are shear diagrams used in the experiment. An explanatory diagram of the box and tamping tool. Figure 12 is an explanatory diagram of the relationship between the diameter and number n of reinforcing materials and the adhesive force C of the soil and the friction angle φ. Figures 13 to 15 are shearing diagrams depending on the number of reinforcing materials. Figure 16 is a diagram to explain the difference in strength, Figure 16 is a diagram to explain the difference in shear strength depending on the reinforcing material insertion angle, Figure 17 is a summary diagram that combines the above diagrams, and Figure 18 is a diagram to explain the difference in shear strength depending on the reinforcing material insertion angle. FIG. 19 is an explanatory diagram showing the relationship between the arrangement and the test results, and FIG. 19 is an explanatory diagram showing the deformation of the reinforcing material after the test.

A. Sample and test method The sample is “masa”, a hornblende andesite collected near Higashimachi, Nagasaki City.
The roughness composition is as follows:
As shown in Figure 9, it is silty sand.

(Preparation of sample) Sample (20) was adjusted again so that the particle size distribution and water content ratio were equalized.

(Tampling of samples) In the shear test, three layers were tamped three times in a shearing box (11) having a bottom plate (21) as shown in Fig. 10, using a tamping tool (12) shown in Fig. 11 to make it homogeneous. did. The degree of tamping was determined using a penetrometer, and the vertical force σ was always set to σ-5 kg. The reinforcing material (13) was inserted after sample preparation. In the triaxial compression test, 6N was tamped six times, the tamping degree was the same as in the shear test, the reinforcing material (13) was inserted in the second layer from the bottom, and the tamping tool (] 2) and the pressure plate were inserted. (22) was used for tamping.

(Reinforcing material) The reinforcing material (13) was made of three types of soft iron wire with diameters of 0.9, 1, 2, and 1.5, and the length was 4.6 cm for direct shearing and 6.0 cm for triaxial compression. .

(Test method) In the direct shear test, there were 0 and 1 reinforcement (13).

There were five types, 2, 3, and 5, and the arrangement and results are shown in FIG. 12 and Table 1.

In the triaxial compression test, 0 and 1 reinforcing material (13) were used.

There were four types, two and three, and the arrangement and results are shown in FIG.

B. Test Results This test examined what changes would occur in the specimen when a foreign object was inserted into the specimen. As shown in Table 1 and FIGS. 12 to 19, the results showed an increase in adhesive force C.

(+> As shown in Figure 12, the internal friction angle φ is
13) was between 33° and 37°, regardless of the number of lines.

-(ii) Adhesive force C increases in proportion to the number of reinforcing materials (13). In Figure 12, the value obtained by dividing the increased adhesive force by the same surface area of the reinforcing material is a value that is almost always returned, and is 0.029 to 0.038, except when there is only one reinforcing material (13).
The tail shows kg f/cnl. The average value is 0.0
It is 33kgf/c.

(iii) In the triaxial compression test, the increasing adhesion force was determined by the reinforcement (
When divided by the same surface area of 13), the value is 0.033 to 0゜036 kgf/cJ, which is almost the same as the value of the direct shear test, and the adhesive force is determined by the peripheral frictional force of the reinforcing material (13). is increasing.

(iv) Regarding the reinforcing material (13), one has sand grains attached with an adhesive to increase the coefficient of friction, and the other has no sand grains.The one without sand grains (however, one reinforcing material) has no reinforcing effect at all. Does not perform well.

(V) As shown in FIG. 19, the reinforcing material (13) after the test did not move in the fixed part of the shear box 00), but bent in the shearing direction. In the triaxial compression test, no deformation of the reinforcing material (13) was observed.

C0 Discussion As a result of the above test, it can be seen that the insertion of the reinforcing material (13) increases the apparent adhesion of the ground, and that it is more advantageous for the peripheral surface of the reinforcing material (13) to have a larger coefficient of friction.

〔Effect of the invention〕

As described above, the present invention connects the surface edges of the reinforcing material cast on the soil slope so as to strongly attract each other, and increases the surface area of the reinforcing material, thereby significantly improving the adhesion of the soil. This has the effect of significantly increasing the shear strength and significantly stabilizing the soil slope.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a soil slope that has been subjected to the stabilization method according to the present invention, Figure 2 is an explanatory diagram of the action of the reinforcement material on the soil slope, and Figures 3 to 5 are the surrounding areas of the reinforcement material. A partially enlarged explanatory diagram of the reinforcement material showing the surface shape, Figures 6 to 8 are explanatory diagrams of the arrangement of the reinforcement material, and Figure 9 is an investigation of the influence of the reinforcement material on soil adhesion and friction angle. A line diagram showing the results of the soil particle size test used in the experiment, Figures 10 and 11 are explanatory diagrams of the shear box and tamping tool used in the experiment, and Figure 12 shows the diameter and number n of reinforcement materials and the soil Explanatory diagram of the relationship between the adhesive force C and the friction angle φ, 1st
Figures 3 to 15 are diagrams that explain the difference in shear strength depending on the number of reinforcing materials, Figure 16 is a diagram that explains the difference in shear strength depending on the reinforcing material insertion angle, and Figure 17 is a diagram that combines the above diagrams. FIG. 18 is an explanatory diagram showing the relationship between the arrangement of the reinforcing material and the test results, and FIG. 19 is an explanatory diagram showing the deformation of the reinforcing material after the test. In the figure: (1): Soil slope (2): Ground surface edge (3): Reinforcement material (4); Rod-shaped object (5): Turning hook (7): Large diameter annular part (8):
Small-diameter annular portion (9): Groove 00): Protrusion Patent applicant: KM Planning Co., Ltd. Agent Masu Tegori (one idiot) Figure 1 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 17 σ (kgf/c port) Old figure Figure 19

Claims (1)

[Claims] 1. Place multiple reinforcing materials regularly or irregularly on the soil slope, divide the reinforcing materials into multiple groups of equal or unequal number of at least two reinforcing materials, and install reinforcing materials for each group. In a method of stabilizing slopes using reinforcing materials, which generates a compaction force on the soil slope by drawing together the surface edges of similar materials using rods or wires with turnbuckles, the peripheral surface of the reinforcing materials is connected to the soil. A method for stabilizing slopes by inserting reinforcing materials, which is characterized by having a shape with a large coefficient of friction.