JPH09209364A - Filling soil construction method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To construct high fill having faces of slope with gradients steeper than a stable gradient that is based on fill strength provided solely by consolidation of a filling material. SOLUTION: An anchor A1, which has a tension member 1 passed through a sheathing pipe 2, a face-of-inslope block 3 freely movably fitted to the outer end 1a of the tension member 1, and an anchored part 4 integrated with the inner end 1b of the tension member 1, is placed on the upper surface of a fill layer E1 with the face-of-slop block 3 located on the outside of the face E1s of slope of the fill layer E1, and with the anchored part 4 anchored to a stable soil part deeper than an assumed sliding surface inside the fill layer E1, to provide a fill layer E2 of a predetermined thickness over the fill layer E1. Thus the anchor A1 is embedded, and the face-of-slope block 3 is clamped and pressed against the faces E1s, E2s of slope by a clamp 5 provided on the outer end 1a of the tension member 1, to impart the required tensile force to the tension member 1. A series of these constructing operations are repeated to construct fill of the required height.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming an embankment which has a high height and has a stable steep slope.

[0002]

2. Description of the Related Art Conventionally, land reclamation in hills and mountains has been accompanied by raising of high embankments and construction of long cut slopes, and the embankments are located in the land of the land. It is common to build up by using earth, sand, gravel, rocks, etc., which are generated locally due to the cut soil of mountains, as embankment material. Then, the embankment material made of these materials is piled up, and the stability calculation is performed based on the strength exerted when compacted to a predetermined density and consolidated, whereby the predetermined safety factor is satisfied and stable. The embankment has been constructed so that it has the slope gradient required for the soil, or the slope gradient empirically determined by the type of embankment material such as whether it is good quality soil or soft soil such as loam. There is. In this case, it is general that the embankment material is formed only by compaction by compaction without applying soil improvement or reinforcement for strength improvement, but especially when the slope is steep. When creating a high embankment, a reinforced earth construction method is used in which a reinforcing material (so-called geotextile) made of a synthetic polymer material that is resistant to pulling is laid at every constant layer thickness in the embankment and raised.

[0003]

However, in the case where the embankment material is given only the strength that the embankment material can originally exhibit by the usual method of only compacting the embankment material, it is possible to create a steep embankment with a certain degree or more. This is not possible, and therefore the slope must be gently sloped to create a high embankment, so it is necessary to acquire a large land for construction. Further, according to the reinforced earth method of embedding a reinforcing material in the embankment, it is possible in principle to create a steep high embankment,
When the embankment height becomes high, the embedding interval of the reinforcing material is narrowed and a large amount of the reinforcing material is required, and the reinforcing material itself is expensive, so that it is actually not suitable for large-scale civil engineering work. Therefore, there is a problem that the height of the embankment that can be formed is limited.

The present invention has been made under the above circumstances, and the technical problem thereof is that the embankment material is compacted only by reinforcing the embankment slope for each constant layer thickness. The object of the present invention is to provide a method capable of constructing a high embankment having a steeper slope than the stable slope due to the embankment strength.

[0005]

The above technical problems can be effectively solved by the present invention. That is, the method of forming the embankment according to the present invention is a method in which a tensile member inserted into a sheath tube and a slope block inserted into the outer end of the embankment layer are provided on the upper surface of the embankment layer having a predetermined layer thickness having a slope at the end in the plane direction. The anchor block is arranged in a state in which the slope block is located outside the slope surface, and the inner end of the tensile member is fixed to a stable ground portion deeper than the assumed slip surface in the embankment layer, and the embankment layer. By embedding and embedding embankment material on the top of the embankment and embedding the embankment layer with a predetermined layer thickness having a slope continuous with the slope of the embankment layer, the anchor is embedded and provided at the outer end of the tensile member. The embankment with a required height is created by repeating a series of creation operations such that the slope block is pressed against the slope with a clamp and the tensile force is applied to the tensile member a predetermined number of times.

The tension member of the anchor used in the present invention presses the slope face surface against the slope face by applying tension between the anchoring portion at the inner end and the slope face block at the outer end, and its supporting force. Is transmitted to the stable ground portion at the back of the assumed slip surface in the embankment layer via the fixing portion, and exerts a reinforcing function necessary for stabilizing the embankment slope. Therefore, it is possible to effectively prevent slip failure on the slope side of the embankment layer, and to create a high embankment with a steeper slope than the stable slope due to the embankment strength given only by compaction of the embankment material. . Further, according to the present invention, the anchors are sequentially buried every time the embankment layer having a predetermined layer thickness is built up, and the embankment layer is reinforced, so that a tensile material is inserted like a normal anchor construction method. Since there is no need to drill a long hole for fixing, the construction is easy.

When the anchor is arranged on the embankment layer and the embankment layer is erected thereon, and if the overburden thickness of the anchor is small, then the slope block of the anchor is tightened and the tension member In the step of giving tension to the, the slope block is temporarily tightened, and after that, the soil cover thickness on the anchor becomes a sufficient thickness, and then the retightening is performed. give.

[0008]

1 to 5 show a preferred embodiment of a method for forming embankment according to the present invention in the order of steps, and FIG. 6 shows an embankment E completed by this method.
2 shows a sectional structure of FIG.

That is, in this embodiment, first, as shown in FIG. 1, a layer thickness ΔH ₁ (see FIGS. 4 and 6) on which a first-stage anchor A1 described later takes charge of reinforcement on a ground foundation B ), The first embankment layer E1 having a slope E1s having a predetermined slope θ is piled up with a layer thickness ΔH _1/2 of about half. In the embankment of the embankment layer E1, for example, a normal embankment material generated by cutting the local ground is spread out by a thickness suitable for one compaction,
The work of compacting by rolling and then spreading the embankment material on it again is repeated a required number of times. In addition,
Layer thickness ΔH ₁ for reinforcement of the first-stage anchor A1
Is a height that does not impair the stability of the slope of the slope θ even when it is raised by using only the normal embankment material.

After the embankment of the first embankment layer E1 has been completed, a required number of recesses 10 are formed on the upper surface, which is the inside of the embankment by embedding the embankment as an upper layer, as shown in FIG. It is formed so as to substantially correspond to the installation position and shape of the eye anchor A1. That is, a plurality of the recesses 10 are provided at appropriate intervals in the direction orthogonal to the illustrated cross section,
In the slope block recess 11 located above the slope E1s of the embankment layer E1, and in the embankment E shown in FIG. 6 that has been completed, it is assumed that the embankment material is formed only by spreading and compacting. The fixing recess 12 is located in a stable region that is deeper than the slip collapse occurrence surface S.

Next, in each recess 10 on the upper surface of the embankment layer E1,
As shown in FIG. 3, the first-stage anchors A1 are arranged. The anchor A1 includes a tension member 1 inserted through a sheath tube 2, a slope block 3 movably inserted into an outer end 1a of the tension member 1, and a fixing portion 4 integrated with an inner end 1b of the tension member 1. Have.

As the tensile member 1, for example, PC steel rod, PC
A tensile-strength linear material such as steel wire, PC steel twisted wire, reinforcing bar, and chemical fiber is used. As the slope block 3, those made of reinforced concrete produced in a factory, those made of cast-in-place reinforced concrete, or those made by combining iron plates, H-shaped steel, I-shaped steel, L-shaped steel, etc. are used. Having sufficient strength to withstand the load applied by applying tension to the tensile member 1 and exhibiting a platform shape suitable for pressing and supporting the slope E1s in a direction parallel to the tensile force of the tensile member 1. And
It is arranged in a recess 11 for a slope block located above the slope E1s in the recess 10. The fixing unit 4 fixes the inner end 1b of the tension member 1 to a stable region deeper than the slip collapse occurrence surface S inside the embankment E described above, and transmits the tension applied to the tension member 1 to the stable region. In order to obtain sufficient anchoring power on the embankment, those made of reinforced concrete blocks produced by factory or cast in situ, those made of locally-generated large-sized rock mass,
Alternatively, it is made of a metal structure or the like in which H-shaped steel, I-shaped steel, L-shaped steel and the like are combined, and is integrated with the inner end 1b of the tension member 1 by screwing, welding, mortar hammering, etc.
It is arranged in the fixing recess 12 of 0. Sheath tube 2
Holds the tension member 1 between the slope block 3 and the fixing unit 4 in a non-contact state with the embankment material and reliably transmits the tension applied to the tension member 1 to the fixing unit 4. It is for.

After the installation of all the anchors A1 of the first stage is completed, as shown in FIG. 4, a slope E2s having a slope θ continuous with the slope E1s is provided on the first embankment layer E1. The embankment layer E2 of the second layer is piled up and formed. The layer thickness of the second embankment layer E2 is the anchor A of the first stage.
1 is the layer thickness ΔH ₁ of the layer thickness ΔH ₁ in the upper half portion, and the second-stage anchor A2 is the layer thickness ΔH _{2 of the} layer thickness ΔH ₂ (see FIG. 6) in the layer thickness ΔH.
Which corresponds to the sum of the _2/2. The formation of the second layer is also performed in the same process as the formation of the embankment layer E1 described above, whereby the anchor A1 of the first stage is formed.
The portion of the tensile member 1 excluding the outer end 1a and the slope block 3 is embedded between the embankment layers E1 and E2, and the fixing portion 4 is firmly fixed to the compacted embankment material.

Next, as shown in FIG. 5, a tightening member 5 such as a nut is screwed onto the outer end 1a of the tension member 1 which penetrates the slope block 3 of the anchor A1 and is tightened to the slope block 3. . As a result, a tension force is applied to the tension member 1 between the fixing portion 4 and the fastening member 5, and as a reaction force thereof, a lower half of the first embankment layer E1 to the second embankment layer E2 is applied. The portion between the slope block 3 and the fixing portion 4 in the region of the layer thickness ΔH ₁ up to the portion is compressed and reinforced toward the portion which becomes the stable region inside the slip collapse surface S described above. .

When the series of construction work up to this point is completed,
The recess 10 is formed on the upper surface of the second embankment layer E2 in the same manner as in FIG. 2, and thereafter, the same construction work as the work up to FIG. 5 described above is sequentially executed. Follow the steps n
By repeating this, the formation of the embankment E having the height H and the slope θ of the slope Es as shown in FIG. 6 is completed. This embankment E
Is an area outside the slip collapse occurrence surface S (slope Es side) that is assumed when the slip collapse occurrence surface S is assumed to be formed only by compaction, through the many anchors A1 to An.
It has a structure that is supported in the stable area at the back. Therefore, the stability of the slope Es of the embankment E is improved and the shear strength of the embankment plate against slip failure is increased, so that the slope can be made steeper than the embankment created only by compacting the embankment material. . Therefore, it is possible to reduce the land (Es · cos θ) taken for setting the slope Es and increase the usable area of the embankment upper surface even if the land area is the same, or the required upper surface area It is possible to save the area of the business land for creating the embankment with.

The number of installation steps of the anchors A1 to An, the installation interval in the height direction, the interval in the lateral direction, and the magnitude of the tension force (tightening force) applied to the tensile member 1 are as follows: S, H, strength of the embankment material, etc. are used for stability calculation, and the reinforcement force required for the entire embankment E to satisfy the predetermined safety factor and be stable is calculated. Will be decided.

When the installation intervals of the anchors A1 to An in the height direction are narrowed, for example, in the case of FIG.
Since the overburden thickness on the upper side of the embankment is thin, that is, the fixing force of the fixing portion 4 due to the load (pressure) of the embankment layer E2 is small, at this point, the tension member formed by tightening the slope block 3 with the tightening metal fitting 5 is used. The tension force of 1 cannot be large enough to give the reinforcing force determined by the above stability calculation. Therefore, in such a case, at the time of giving tension to the anchor in each construction process, that is, for example, in FIG.
In the step shown in (1), the fastening metal fitting 5 of the anchor A1 is temporarily tightened to raise the height (ΔH ₁ +
ΔH _2/2) previously given only a stability necessary reinforcement force embankment in a view point overburden thickness above becomes sufficient thickness of the anchor A1 or prime fresh embankment E, it has been completed 6
Tighten with the tightening bracket 5 at the time shown in
It is sufficient to give the reinforcing force necessary for the stability of the entire embankment E.

[0018]

According to the embankment forming method of the present invention,
The following effects are realized. (1) Since the anchors reinforce the lack of strength necessary for the stability of the embankment created only by raising and compacting the embankment material consisting of soil or gravel,
It is possible to prevent the occurrence of slip failure on the embankment slope. (2) Since the strength of the embankment slope against landslides increases, it is possible to create a high embankment with a steep slope, and therefore the business site necessary for expanding or creating the site area on the embankment. The area can be saved. (3) Unlike the normal anchor construction method, it is not necessary to construct a deep drilling hole for installing the anchor, and the anchors are sequentially buried in the process of building up the embankment layer with a predetermined layer thickness,
Construction is easy because the embankment layer is reinforced. (4) Since the reinforcement by the anchors is sequentially performed during the process of forming the embankment layer having the predetermined layer thickness, the deformation can be effectively suppressed even when the embankment has a steep slope. (5) When an abnormality such as excessive deformation occurs in the embankment, the stability of the slope can be improved by tightening the anchor to increase the reinforcing force.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a first embankment layer in an embodiment of a method for forming embankment according to the present invention.

FIG. 2 is an explanatory diagram showing a state in which a recess for arranging an anchor is formed on the upper surface of the first embankment layer in the above embodiment.

FIG. 3 is an explanatory view showing a state in which anchors are arranged on the upper surface of the first embankment layer in the embodiment.

FIG. 4 is an explanatory view showing a state in which an anchor is embedded by embedding a second embankment layer on the upper surface of the first embankment layer in the embodiment.

FIG. 5 is an explanatory view showing a state in which the slope block of the anchor is tightened in the above embodiment.

FIG. 6 is a cross-sectional view showing an embankment formed by the forming method of the present invention.

[Explanation of symbols]

 A1 to An Anchor E Embankment E1, E2 Embankment layer Es, E1s, E2s Slope 1 Tension material 2 Sheath pipe 3 Slope block 4 Anchoring part 5 Tightening fitting

Claims (2)

[Claims] 1. An anchor consisting of a tensile member inserted into a sheath tube and a slope block inserted into the outer end of the embankment layer, which is inserted into a sheath tube, is provided on the upper surface of an embankment layer having a predetermined thickness and having an inclined surface at the end in the plane direction
Arranging the slope block outside the slope and fixing the inner end of the tensile member to a stable ground portion deeper than the assumed slip surface in the embankment layer, and on the embankment layer A step of embedding the anchor by squeezing out and compacting the embankment material and embedding a embankment layer having a predetermined layer thickness having a slope continuous with the slope of the embankment layer; A method for forming an embankment, which comprises repeating a forming operation consisting of a step of applying a required tension force to the tensile member by tightening and pressing a slope block to the slope with a tightening fitting a predetermined number of times. 2. In the step of applying tension to the tension member of the anchor in the construction work of each step, the slope block of the anchor is temporarily tightened, and the earth cover thickness on the anchor becomes equal to or more than the required thickness. The method for constructing an embankment according to claim 1, wherein the tightening is performed at a point of time.