JPS59199911A - Construction work of banking - Google Patents

Abstract

PURPOSE:To make up for shortage of tensile strength of a banking by eliminating scouring by rain water, etc., and degradation by lowering of the internal shearing strength by a method in which plural banking layers and plural ground reinforcing layers are alternately formed and a slope wall made of the same material as the reinforcing layer is formed even on the sloped portion. CONSTITUTION:A powdery granule 1 in dry state, not mixed with water, is spread over the surface of the bottom ground where banking is to be constructed, a tense material 2 is laid on the powdery granule and anchored, the powdery granule 1 is spread on the tense material 2, and the first banking layer is formed on the tense material 2. The banking layer A is formed till a position retracted from the final slope face, a front net 3, together with a formwork 4, is attached, and a powdery granule 1 of the same material as a reinforcing layer B is put between the net 3 and the first banking layer. Afterwards, the same operations are repeated to construct the second layer and higher layers to a target height. The water-absorbed ground reinforcing layers and the slope layer are strongly hardened together.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates primarily to an embankment construction method used when constructing important structures or structures, and is applied to relatively large-scale embankments.

Prior art Embankment construction has traditionally been a simple process of dividing the soil into several layers and compacting them. In the case of B, depending on the soil quality, it is necessary to make the slope of the υ plane rather gentle.

Furthermore, if a large amount of rain falls soon after construction, ordinary embankments will be washed away, or the pore water pressure within the ground will increase, reducing internal shear resistance and causing failure. Furthermore, the stability of an embankment is controlled by the shear strength of the compacted soil. The biggest weakness of these earth structures is that they have almost no tensile strength.

Various countermeasure construction methods have been studied for a long time to address the above problems, and partial solutions have been developed for each, and various construction methods are still being applied today.

For example, a sheet is laid on the slope to prevent direct rainwater, and a slope is protected by planting vegetation with its buds, stems, roots, etc.
Slope stabilization methods such as those that lay blocks, drainage promotion methods that involve laying pipes or highly permeable non-woven fabric within the embankment, the Terre Alme method and early reinforced earth construction methods.
There is a reinforcement method called reinforced soil, which involves inserting tensile strength materials into the embankment.

However, these construction methods cannot solve all problems at once. Conventional countermeasure construction methods have only partially solved these problems, but each construction method still has many problems apart from its advantages.

Purpose of the Invention This invention was invented in order to solve the above-mentioned problems of the prior art. The purpose is to provide an embankment reinforcement method that can be used.

Structure of the Invention In the embankment construction method of the present invention, a powder solidified material such as cement material and a coarse granular material such as sand are mixed in a dry state and spread and laid, and groundwater, rainwater, and moisture from watering etc. are absorbed if necessary. In particular, it forms porous, highly permeable soil reinforcement layers and walls.

The ground reinforcing material layer is formed to be sandwiched between multiple embankment layers, and as mentioned above, the mixed powder solidified material and coarse granular material are spread and laid in a dry state, and in the middle, rod-shaped or fibrous steel materials, chemical A tensile material made of a synthetic material or other material with tensile strength is laid down, and a powder solidified material and a coarse granular material are further sprinkled on top of it. In addition, the thickness of each layer of ground reinforcement material is, for example, 100
The thickness should be approximately 300 mm to 300 mm.

As for the granular solidification material made of cement material, consider the particle size and composition of powder assimilated material and coarse granular material such as sand. ・By directly applying the mixed material on site, it will improve the water usage reaction with ground water and rainwater. During this process, a mortar that is permeable to water is created by the flow of water.

In addition, a similar mixture of powder solidified material and coarse grain material is spread on the υ side of the wall to form a porous wall that is permeable to water by absorbing moisture.

During construction, the aforementioned ground reinforcement layers and embankment layers are constructed alternately to complete the embankment at the planned height. On the other hand, for the surface of
Powder solidifying material and coarse granule material are spread and laid down to a position set back by cIn~50. As a result, the soil reinforcing material layer and the slope wall, which have absorbed water, harden and a stable and strong embankment is completed.

Example The illustrated embodiment will be described below.

Figure 1 shows the structure of an embankment. The embankment is divided into multiple embankment layers A, and the embankment layers A and reinforcing material layers B are alternately provided.
A glue wall C made of the same material as the reinforcing material layer B is formed on the υ surface portion of the reinforcing material layer B.

Figures 2 to 6 show the construction process, and the work is carried out in the following steps.

(1) As shown in Figure 2, powder 1, which is a mixture of appropriate amounts of granular solidified material and coarse granular material (sand, etc.), is placed on the ground surface of the bottom where embankment is to be performed, without being mixed with water, and in a dry state. Spray at a thickness of 50 to 200 bars.

(2) Lay the tensile material 2 on top of it. Here, we will specifically discuss an example using an unbonded cable. After anchoring and other treatments are applied to this, powder 1 is again sprinkled on it to a thickness of 50 to 100 m as shown in FIG.

(3) A first layer of embankment is applied on top of this as shown in FIG. 4 to form embankment layer A. The embankment material may be anything that can form an earthen structure, such as sand or loam. In addition, this embankment layer A itself is 30a to 5oCrf from the final slope surface.
Leave L as far as the backward position.

(4) Next, as shown in FIG. 5, the front net 3 for forming the final slope surface is attached together with the formwork 4.

(5) As shown in FIG. 6, the powder 1 used for the reinforcing material NB is placed in the space between the front net 3 and the first embankment layer A.

(6) Similarly, repeat the operations (1) to (5) to construct the second and higher layers to complete the embankment of the desired height shown in FIG.

In addition, when an unbonded cable is used as the tensile material 2, it is possible to perform tensioning work during and after construction to correct the shape of the surface of the ground by applying compressive force to the ground.

Figure 7 shows its structure, where 5 is a sheath and 6 is a sheath.
is a fixed end. Furthermore, even after completion, if stress decreases or deformation of the surface occurs due to creep or ground movement, re-tensioning may become necessary. Therefore, Fig. 8(a),
(b) As shown in K, an oil cap 7 is attached to the anchor head to prevent damage due to corrosion. In addition, as shown in FIG. 9, mortar 8 is placed inside the sheath 5 to make it fixed.
The steel material in the sheath 5 can also be constructed by using a material injected with it to prevent corrosion.

Effects of the invention ■ Since the material with high permeability quickly drains the inside of the embankment and the surface of the embankment, it reduces the scouring caused by rainwater etc. in the early stage after construction is completed, which is often seen in ordinary embankments, and the pore water pressure inside the embankment. There is no collapse due to a decrease in internal shear strength due to the rise.

■ Workability is good because the mortar that forms the structure does not need to be mixed with water and mixed in a mixer as in the conventional method, and transportation of materials, quality control, and construction are easy, making it highly economical.

■ The mortar that forms the structure is solidified by underground water and rainwater, so it hardens at the optimal water-cement ratio of the solidifying material, allowing the material to exhibit its maximum strength.

■ The mortar used in the structure is made of a highly water-permeable material, so there is no need for a device to drain water from behind, unlike traditional retaining walls. For example, there is no need for a water drain pipe or a drain sheet on the back. In this way, the mortar on the front protects, reinforces, and drains the front surface.

■ Since tensile material is added, it can sufficiently compensate for the lack of tensile strength, which is the biggest weakness of soil. For this reason, the embankment is not only able to carry a load Xt(M) that cannot be handled by conventional embankments, but also can withstand earthquakes.

In addition, an unbonded cable can be used as the tensile material to prestress the embankment and then retension it. In this case, the compressive force of the embankment will increase, and settlement or deformation due to the overloading of the embankment will occur. It becomes less. This is because compressive force is added and the shear strength of the embankment increases.

■ Adding prestress to the tensile material increases the shear strength of the embankment, and the amount of reinforcing steel material can be reduced, making construction easier and more economical. Further, since compressive force is applied to the mortar of the reinforcing material layer, tensile cracks do not occur. Therefore, there is no separation of the permeable layer, allowing for smooth drainage.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing the structure of the embankment, Figures 2 to 6 are vertical cross-sectional views showing the construction procedure, Figure 7 is a vertical cross-sectional view of tension members using unbonded cables, and Figure 8 (a) is a vertical cross-sectional view showing the construction procedure. FIG. 8(b) is a longitudinal sectional view of the cap of the anchor head, FIG. 8(b) is a perspective view of the cap, and FIG. 9 is a longitudinal sectional view of the fixed tension member. A... Embankment layer, B... Reinforcement layer, C... Glue wall, 1...
Powder, 2. Tensile material, 3. Front net, 4. Formwork, 5. Sheath, 6. Fixed end, 7. Cap, 8.
Mortar of life. Figure 4A Figure 5 Figure 6 Figure 50- Figure 7 Figure 8 (a) (b) Figure 9

Claims (4)

[Claims] (1) An embankment construction method that forms a ground reinforcing material layer arranged in layers between multiple embankment layers and a wall on the side of the embankment, wherein the ground reinforcing material layer is made of granular material. Dried powder solidified material and coarse granular material are mixed, spread and laid in layers at a specified thickness on site, and tensile material for shear reinforcement is installed in the middle.
The embankment is constructed alternately with embankment layers up to the planned height of the embankment, and for the slope wall, dry powder solidified material and coarse granular material in the same powder state as the ground reinforcement layer are mixed, and On the other hand, this embankment construction method is characterized by spreading the earth to a predetermined thickness and hardening it by absorbing moisture to form a ground reinforcement layer and a slope wall that have a porous structure with water permeability. (2) The embankment construction method according to claim 1, wherein the powder solidifying material is a cement material. (3) The embankment construction method according to claim 1 or 2, wherein the coarse-grained material is sand. (4) The embankment construction method according to claim 1, 2, or 3, wherein the tensile material is a bar-shaped tensile steel material or an unpond cable.