JPH0696857B2 - Foamed resin block civil engineering method and earth anchor used to prevent the embankment structure from rising - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a case where a road or the like must be constructed on a soft ground where the earth and ground will sink due to the weight of the earth and sand when embankment is carried out using ordinary earth and sand. Instead, by improving the so-called foamed resin block civil engineering method (EPS method) in which a foamed resin block (EPS body) made of foamed polystyrene or the like, which is lightweight, is used to obtain a fill, and the foamed polystyrene block is used by the method. The present invention relates to an earth anchor for preventing an embankment structure including a block or the like from being lifted by the action of buoyancy caused by groundwater.

[0002]

2. Description of the Related Art As is known, in recent years, the EPS method has come to be applied to embankments on soft ground with a large subsidence amount, and since an EPS body that is lighter than earth and sand is used,
It has a great effect of reducing ground subsidence, which prevents the function of the embankment from deteriorating.

However, when the EPS method is carried out in a place where the groundwater level is high, or when the groundwater pressure suddenly increases due to a heavy rainfall, the weight of the EPS body is light, so this is included. A considerably large buoyancy force acts on the embankment structure to be formed by various members, and as a result, the embankment structure floats up, and there is a concern that it will not be able to serve as the embankment.

Therefore, in order to effectively prevent such floating, the following two measures have already been taken. That is, one is to add a load that can counter the buoyancy to the upper part of the EPS body, and the other is to select a solid ground in the ground and fasten the lower part of the earth anchor to this. , The head of the earth anchor is fixed to a reinforced concrete slab in the upper layer of the embankment structure,
As a result, buoyancy is countered by the pulling force of the earth anchor.

However, in the above-mentioned measures by the former, as a matter of course, since the earth is placed on the EPS body used for reducing the weight, the effect of reducing the load is reduced. Become.

In the latter case of the earth anchor,
The lower part is fixed to a solid ground, and the head is fixed to the embankment structure, so for buoyancy due to groundwater,
Although this earth anchor can prevent the embankment structure from rising, when the subsidence phenomenon occurs on the soft ground, the earth anchor causes the embankment structure to be prevented from sinking following the ground. Therefore, we have to worry about the occurrence of serious obstacles such as the formation of voids between the ground and the embankment structure.

[0007]

In view of the above-mentioned conventional defects, the present invention provides the EPS construction method using the former earth anchor, in which the earth anchor is fixed to a specific length. By providing a connection mechanism for preventing reverse movement in the earth anchor without losing it, when buoyancy is applied to the embankment structure due to the water level of the groundwater, the above connection mechanism ensures an immovable state, The length of the earth anchor is maintained unchanged, which prevents the embankment structure from rising due to buoyancy, and when ground subsidence occurs, the earth anchor slides its length by the above-mentioned connecting mechanism. Its purpose is to reduce the size of the embankment structure so that it can follow the ground subsidence.

According to a second aspect of the present application, with respect to the structure of the earth anchor used in the EPS method of the above-mentioned first aspect, the earth anchor is not made to have a fixed length, but a reverse motion prevention connection. By properly interposing a mechanism, it is possible to prevent the earth anchor from changing in the extension direction, to prevent the embankment structure from rising due to buoyancy, and to perform the contraction method. It is intended to ensure that the embankment structure can follow this during subsidence by making it possible to change to.

Further, according to a third aspect of the present invention, in the earth anchor of the second aspect, the reverse movement preventing connecting mechanism is covered with a flexible pipe containing a rust preventive agent. It seeks to ensure permanent full operation of the linkage.

[0010]

In order to achieve the above object, the present invention provides a light-weight laminate in which foamed resin blocks are laminated on a soft ground having a large sinking amount, and the light-weight laminate is sequentially arranged thereon. In the embankment construction method in which the load-equalizing plate using the reinforced concrete plate, etc., and the upper layer body form the embankment structure that is the main constituent member, the lower part of the earth anchor for prevention of uplift is placed under the ground. The head anchor is fixed to the load equalizing plate body, and the earth anchor is provided with a reverse motion preventing connection mechanism that prevents the expansion and allows the contraction. When the fluctuation or increase in groundwater pressure is caused, the earth anchor prevents the embankment structure from rising, and when the soft ground subsides, the earth anchor is reduced by the connecting mechanism to reduce the embankment structure. We are trying to provide a foamed resin block civil engineering method being characterized in that to be able to follow the subsidence soft ground.

According to a second aspect of the present invention, an anchor rod for fixing the lower portion to a fixing portion provided on a solid ground of the ground, and an upper end spiral portion provided in the lightweight laminated body of the anchor rod are screwed. A reverse movement preventing connection mechanism, an insertion pipe to which the nut body of the connection mechanism is fixed, and a pipe head projecting into the upper layer body through the load equalizing plate body of the insertion pipe. A head fixing mechanism for fixing to the load equalizing plate body, wherein the connecting mechanism includes the front nut body, a plurality of screw pieces, and a spring,
On the inner peripheral side of each of the screw pieces, an inner peripheral divided female screw portion that is screwed into the upper end spiral portion of the anchor rod is provided, and on the outer peripheral side thereof, there is a downward taper inside the nut body. A sliding taper surface that is in sliding contact with the peripheral surface is formed, and the spring is provided on the nut body so as to be able to press the plurality of screw pieces downward, and a fixed anchor rod is inserted into the fixing portion. Movement in the direction of contraction that enters the pipe is allowed by the upward movement of each screw piece that resists the elasticity of the spring, and movement in the opposite direction is downward of each screw piece that engages with the anchor rod. Displacement of the sliding taper surface is stopped by pressure contact with the taper inner peripheral surface of the foamed resin block civil engineering method and the earth anchor for preventing the embankment structure from floating up. To Than it is.

Further, in addition to the constitution of the above-mentioned claim 2, the third aspect of the invention is such that the upper part is fixed to the insertion pipe and the anchor rod is covered, and the lower part is fixed to the fixing part. The content is that the flexible pipe and the injected rust preventive agent are arranged in the flexible pipe.

[0013]

In the styrofoam civil engineering method according to claim 1, when the groundwater level or groundwater pressure becomes large and a large buoyancy force acts on the embankment structure due to the foamed resin block or the like, it is attached to the embankment structure. Since the extension of the earth anchor is prevented by the reverse movement preventing connection mechanism, the lower part is fixed to the anchoring part of the ground and the head is fixed to the load equalizing plate body such as reinforced concrete plate. The earth anchor prevents the lightweight embankment structure from rising.

Next, when the soft ground subsides, the earth anchor of the embankment structure formed thereon is shortened by the operation of the reverse motion preventing coupling mechanism, and the subsidence occurs together with the ground. However, it prevents the formation of voids between the ground and the embankment structure.

When the earth anchor of claim 2 is used, the head and the lower portion are fixed as described above, and when the embankment structure is subjected to buoyancy due to groundwater,
An upward force is applied to the insertion pipe and the nut body fixed to it, and as a result, a screw piece having a sliding taper surface between the upper spiral portion of the anchor rod and the taper inner peripheral surface of the nut body. The body bites into a wedge shape, so that the length of the earth anchor does not change and the embankment structure is prevented from rising.

Next, when the ground is subsided, a downward force is applied to the insertion pipe and the nut body due to the load of the embankment structure, so that the screw piece can slide upward against the elastic force of the spring. Therefore, the screwing state of the inner peripheral divided female screw portion and the anchor rod is released,
The upper end spiral portion of the anchor rod enters into the insertion pipe, so that the earth anchor can be reduced, and the embankment structure also sinks following the settlement of the ground.

Further, according to the third aspect, since the anchor rod is immersed in the rust preventive agent in the flexible pipe, and the reverse movement preventing coupling mechanism also exists in the rust preventive agent, the earth anchor is used. The durability is secured and the earth anchor expands and contracts, but since it is a flexible pipe, it can be deformed even when it is contracted, so there is no leakage of the rust preventive agent.

[0018]

EXAMPLE FIG. 1 shows an earth anchor used to carry out the foamed resin block civil engineering method according to the present invention.
Through FIG. The foamed resin block civil engineering method is to form the embankment structure A on the soft ground 1 with a large amount of subsidence as is known, but in order to create the embankment structure A shown in the figure, first, on the soft ground 1 above. A sand layer 3 for adjusting the unevenness (horizontal) is formed on the sheet through a mixing prevention sheet 2 made of polypropylene or the like, and a foamed resin block 4a made of Styrofoam or the like is laminated on the sand layer 3 to form a lightweight laminate 4 as an EPS body. Make up.

Further, a load equalizing plate body 5 such as a reinforced concrete slab is arranged in order to apply an even load to the light weight laminated body 4, on which a roadbed 6a and a surface layer 6b such as a pavement are sequentially arranged. By applying the upper layer body 6 by
The embankment structure A is obtained.

At this time, in the present invention, the earth anchor B as shown in FIG. 1 is embedded as follows at the time of construction of the Styrofoam civil engineering method. That is, soft ground 1
Therefore, the fixing section 7 is provided by selecting a solid ground.
Then, the lower part of the anchor rod 8 of the earth anchor B is fixed.

Cement or the like is used for the fixing portion 7, and reference numeral 8a in the drawing denotes a retaining bulge portion of the anchor rod 8 in the fixing portion 7, and the anchor rod 8 corresponds to the length thereof and has a cup shape. By the connecting means by the ring 8b,
The required length will be extended upward.

In the illustrated example, the fixing unit 7 has the mixing prevention sheet 2
And the sand layer 3 are pierced and the light weight laminate 4, the load equalizing plate 5, and the roadbed 6a are provided with vertical through holes 9 for the ground anchor A, and the extension The upper end spiral portion 8c of the anchor rod 8 thus formed is incorporated in the lightweight laminated body 4.

On the other hand, in the vertical through hole portion 9, the roadbed 6
a, the lower end portion of the insertion pipe 10 which is vertically mounted from the load equalizing plate body 5 to the lightweight laminated body 4, and the upper end spiral portion 8 described above.
A reverse movement preventing coupling mechanism 11, which will be described later in more detail with reference to FIG.

Further, in order to fix the head of the earth anchor B to the load equalizing plate 5, the head fixing mechanism 12 having the following structure is provided in the illustrated example. That is, the insertion pipe 10 is fixed to the fixing pipe 10b through the mortar 10a, and the fixing pipe 10b
The H-shaped steels 13a and 13b are fixed to the upper end of the fixing pipe 10b extending to the roadbed 6a of b, and the seat plates 14a and 14b are provided above and below the H-shaped steels 13a and 13b, respectively.
And the fastening nut 15 is screwed onto the screw head 10c of the insertion pipe 10 to configure the head fixing mechanism 12. Here, reference numeral 16 in the drawing denotes a protective concrete for preventing corrosion provided to the vertical through hole portion 9 in the roadbed 6a.

Next, the reverse movement preventing coupling mechanism 11 will be described in detail with reference to the embodiment shown in FIG. 3. The nut body 11a is fitted and fixed inside the lower end of the insertion pipe 10.
And a plurality of screw piece bodies 11b, 11b installed therein
, And a spring 11d sandwiched between the pieces 11b, 11b, ... And the upper end lip 11c of the nut body 11a.

On the inner peripheral side of the screw pieces 11b, 11b, ..., An inner peripheral divided female screw portion 11e which is screwed with the upper end spiral portion 8c of the anchor rod 8 is provided, and on the outer peripheral side thereof. A sliding taper surface 11g that slidably contacts the tapered inner peripheral surface 11f that is tapered downward is formed on the nut body 11a, and 11h in the drawing is the upper end lip 1 of the nut body 11a.
The through-hole opened in 1c is shown.

Further, as shown in FIGS. 1 and 2, a flexible pipe 17 is provided so as to cover the anchor rod 8, and its upper portion is fitted and fixed to the lower end portion of the insertion pipe 10. At the same time, the lower portion of the pipe 10 is fixed to the fixing portion, and the rust preventive agent 18 is injected into the flexible pipe 17, so that the reverse movement preventing coupling mechanism 11 and the coupling are provided. 8b will be immersed in the rust preventive agent 18.

Therefore, when the foamed resin block civil engineering method applied with the earth anchor B as described above is used, the groundwater level rises as in the conventional methods.
Even when an upward external force is applied to the insertion pipe 10 by the buoyancy of the embankment structure A including the foamed resin block 4a, the wedge-shaped action of the screw pieces 11b, 11b, ...
Since the inner peripheral divided female screw portion 11e and the upper end spiral portion 8c are sufficiently screwed together, the extension of the ground anchor B is prevented.
Uplift of the embankment structure A will be suppressed.

When ground subsidence occurs in the soft ground 1, the pressing force of the embankment structure A acts on the insertion pipe 10. In this case, the screw in the connecting mechanism 11 is used. Since the piece body 11b moves upward against the elastic force of the spring 11d, the wedge-shaped action is released, the inner peripheral divided female screw portion 11e and the upper end spiral portion 8c are loosely screwed, and the earth anchor B can be reduced. As the upper spiral portion 8c enters the insertion pipe 10, the embankment structure A descends following the subsidence of the soft ground 1.

Since the flexible pipe 17 is deformed into a bellows-like state as shown in FIG. 2 due to the contraction of the ground anchor B due to the subsidence of the ground, the rust preventive agent 18 does not leak and the flexibility is reduced. There is no breakage of the pipe 17.

[0031]

Since the present invention can be carried out as described above, when the civil engineering method according to claim 1 is used, by embedding the earth anchor during construction, the embankment structure can be floated by groundwater as usual. Uphill can be prevented, and even if there is ground subsidence, the embankment structure can follow it, so that the effect as embankment can be guaranteed for many years.

By using the earth anchor according to the second aspect of the present invention, the reverse movement preventing connecting mechanism prevents the earth anchor from expanding and allows the earth anchor to contract due to the wedge-shaped action of the screw piece body, so that the earth anchor is highly reliable. The anchor has a relatively simple structure,
It can be provided at low cost.

According to the third aspect, the reverse movement preventing coupling mechanism according to the second aspect is protected by the rust preventive agent, and the flexible pipe can be used to reduce the earth anchor without any trouble. It can have high reliability.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional front view showing an earth anchor used in a foamed resin block civil engineering method of the present invention.

FIG. 2 is a vertical sectional front view showing a reduced state of the earth anchor in FIG.

FIG. 3 is an enlarged vertical sectional front view showing a connecting mechanism portion for preventing reverse movement in the earth anchor.

[Explanation of symbols]

 1 Soft Ground 4a Foamed Resin Block 4 Lightweight Laminate 5 Load Equalizing Plate 6 Upper Layer 7 Fixing Part of Natural Ground 8 Anchor Rod 8c Upper Spiral Part 10 Insertion Pipe 11 Reverse Locking Connection Mechanism 11a Nut Body 11b Screw Piece 11d Spring 11e Inner divided female screw portion 11f Tapered inner peripheral surface 11g Sliding tapered surface 12 Head fixing mechanism 17 Flexible pipe 18 Rust preventive agent A Embankment structure B Earth anchor

Claims (3)

[Claims] 1. A main structure comprising a light-weight laminate in which foamed resin blocks are laminated on a soft ground having a large subsidence amount, a load-equalizing plate made of a reinforced concrete slab, etc., and an upper layer, which are sequentially arranged on the lightweight laminate. In the embankment method that forms the embankment structure that is a member, the lower part of the earth anchor for floating prevention is fixed to the solid ground of the ground, and the head is fixed to the load equalizing plate. In addition, the earth anchor is provided with a reverse movement preventing connection mechanism that prevents the expansion and allows the contraction, and when the groundwater level changes or the groundwater pressure increases, the earth anchor is used to remove the embankment structure. Prevents lift-up, and during subsidence of soft ground,
A foamed resin block civil engineering method characterized in that the earth anchor is reduced by the connecting mechanism so that the embankment structure can follow the settlement of the soft ground. 2. An anchor rod for fixing a lower portion to a fixing portion provided on a solid ground of the ground, and a reverse movement prevention screwed on an upper end spiral portion arranged in the lightweight laminated body of the anchor rod. The load equalizing plate includes a connecting mechanism, an inserting pipe to which a nut body of the connecting mechanism is fixed, and a pipe head that penetrates the load equalizing plate body of the inserting pipe and projects into the upper layer body. A head fixing mechanism for fixing to the body, the connecting mechanism includes the front nut body, a plurality of screw pieces, and a spring, and the inner peripheral side of each screw piece is An inner peripheral divided female screw portion that is screwed into the upper end spiral portion of the anchor rod is provided, and a sliding taper surface that is slidably in contact with a tapered inner peripheral surface of the nut body is formed on the outer peripheral side thereof. Then, the spring is
The nut body is provided on the nut body so that the plurality of screw pieces can be pressed downward, and the anchor rod fixed to the fixing portion moves into the insertion pipe in the contraction direction by the elasticity of the spring. Allowed by the upward movement of each screw piece to resist, the downward movement of each screw piece that engages with the anchor rod is stopped by the pressure contact of the sliding taper surface with the taper inner peripheral surface. The foamed resin block civil engineering method and the earth anchor for preventing the embankment structure from being lifted up. 3. An anchor rod for fixing a lower part to a fixing portion provided on a solid ground of the ground, and a reverse movement prevention screwed on an upper end spiral portion distributed in a lightweight laminated body of the anchor rod. The load equalizing plate includes a connecting mechanism, an inserting pipe to which a nut body of the connecting mechanism is fixed, and a pipe head that penetrates the load equalizing plate body of the inserting pipe and projects into the upper layer body. A head fixing mechanism for fixing to a body, a flexible pipe having an upper portion fixed to the insertion pipe and covered with an anchor rod, and a lower portion fixed to the fixing portion, and the flexible pipe. Consisting of a rust preventive injected into the inside, the connecting mechanism includes the same nut body, a plurality of screw pieces, and a spring, and the inner peripheral side of each screw piece has An inner peripheral split female screw part that engages with the upper spiral part of the anchor rod is provided. At the same time,
A downwardly tapered tapered inner peripheral surface is formed on the nut body to form a sliding taper surface, and the spring is provided on the nut body so as to be able to press the plurality of screw pieces downward, and the fixing means is provided. The movement of the anchor rod fixed to the portion in the contraction direction to enter the insertion pipe is allowed by the upward movement of each screw piece against the elastic force of the spring,
As for the movement in the opposite direction, the downward displacement of each screw piece screwed with the anchor rod is stopped by the pressure contact of the sliding taper surface with the taper inner peripheral surface. Civil engineering method and earth anchor used to prevent the embankment structure from rising.