JP2015229890A - Reinforcement construction and quality control method for earth structure using injection type natural ground reinforcement material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reinforcement construction and quality control method for an earth structure using an injection type natural ground reinforcement material, which prevents an important structure such as an adjacent rail track from being affected by ground deformation caused during construction due to the upheaval or depression and settlement of the natural ground.SOLUTION: In a reinforcement construction and quality control method for an earth structure using an injection type natural ground reinforcement material, reinforcement is performed while deformation caused during construction due to the upheaval or depression and settlement of natural ground is suppressed to the utmost, when an earth structure such as fill and an earth retaining wall, adjacent to a rail track, a road, a house and the like, is reinforced with the injection type natural ground reinforcement material. A drilled hole diameter is set smaller.

Description

  The present invention relates to a method for reinforcing construction and quality control of an earth structure using an injection type natural ground reinforcing material. Changes in uplift of ground (ground) during construction when earth structures such as embankments and retaining retaining walls near railway tracks, roads, houses, etc. are reinforced with injection-type ground reinforcement The present invention relates to a reinforcement construction / quality control method for reinforcing the shape while suppressing it as much as possible.

  Conventionally, when embankment and earth retaining wall are reinforced with natural ground reinforcement in places where there are concerns about the impact on nearby structures such as railways, roads, and houses due to the construction of natural ground reinforcement As shown in FIG. 5, there is a risk of deformation due to the uplift of the natural ground. That is, if the embankment or retaining wall 101 is reinforced by the natural ground reinforcing material 102, the ground surface 103 of the natural ground is raised, and the function of the road and the railroad track is adversely affected. In order to suppress this adverse effect, measures such as using a casing during drilling have been taken. In addition, a method of constructing a large-diameter ground reinforcement without performing drilling using a technique of mechanical ground improvement method (radish anchor method) has been used.

  However, the method using the casing is complicated and not economical. Moreover, when constructing a reinforcing material having a medium diameter to a large diameter (about 20 cm to 50 cm), the construction itself becomes much more difficult. On the other hand, in the method using the mechanical ground improvement method, it is possible to construct medium- to large-diameter reinforcing materials in a state where the deformation of the ground is suppressed. Construction is difficult on the ground. In addition, when both methods are used to reinforce retaining walls and the like, it is necessary to provide a hole slightly larger than the diameter of the reinforcement in the retaining wall to be reinforced. In addition, there were many problems such as the risk of breaking the reinforcing bars of the existing retaining wall.

Japanese Patent No. 3731189 Japanese Patent No. 3709505 Japanese Patent No. 3757400

  In particular, in the reinforcement of existing retaining wall retaining walls, it is necessary to drill holes in existing retaining walls for the construction of natural ground reinforcement, but this reduces the risk of rebar breakage during drilling and reduces the construction costs associated with drilling. There is a need to.

  Also, when reinforcing existing embankments and retaining walls, important structures such as nearby tracks are not affected by uplift of the ground (ground) or ground deformation during construction such as depression or subsidence. It is necessary to.

  In order to solve the above-mentioned problems, the present invention prevents an influence on an important structure such as a nearby track by a ground deformation during construction such as an uplift of a natural ground (ground) or depression or subsidence, The purpose is to provide a method for reinforcing construction and quality control of earth structures using pouring type natural ground reinforcement.

In order to achieve the above object, the present invention provides
[1] Uplift of ground (ground) that occurs during construction when earth structures such as embankments and retaining retaining walls near railroad tracks, roads, houses, etc. are reinforced with injection-type ground reinforcement Alternatively, in a method for reinforcing construction and quality control of an earth structure using an injection-type ground reinforcing material that reinforces while suppressing deformation of sinking and sinking as much as possible, the drilling hole diameter is reduced.

  [2] In the earthen structure reinforcement construction / quality control method using the injection type ground reinforcement according to [1] above, a packer is attached to the mouth portion of the drilling portion, and the relationship with the constraint pressure at the position. The packer pressure is controlled.

  [3] In the method for reinforcing construction and quality control of an earth structure using the injection type natural ground reinforcing material according to [2] above, in the construction of the injection type natural ground reinforcing material, a track on a track surface or a road ( The vertical displacement of the (pavement) surface is constantly monitored, and if there is a risk that the displacement of the track or road (pavement) surface will exceed the control value, the packer pressure is unloaded immediately and the injected material leaks from the mouth. And

  [4] In the method for reinforcing construction and quality control of earth structures using the injection type ground reinforcement according to [3] above, infiltrate and inject into the ground clearance in a small area (about 10 cm to 30 cm) around the injection pipe. It is characterized by suppressing displacement during construction.

  [5] In the earthen structure reinforcement construction and quality control method using the injection-type ground reinforcing material according to [2] above, two quality items are set by setting two control items of ground deformation and injection pressure. It is characterized by practicing safety management.

  According to the present invention, the following effects can be achieved.

   (1) The effect of adopting the injection type natural ground reinforcing material of the present invention is that the hole in the mouth is the minimum diameter necessary for the installation of the injection pipe. The drilling hole can be small.

   (2) When reinforcing a retaining wall or embankment in the vicinity of an important structure such as a track, the limit value of the allowable displacement may be in mm units, requiring much higher construction management. Therefore, a packer is installed at the mouth in advance, and the packer pressure is equivalent to the restraint pressure of the natural ground reinforcement at that point (for example, vertical pressure due to earth cover pressure and gauge weight in the case of construction directly under the track) When the injection pressure exceeds the restraint pressure, the packer is released, and the injection material leaks in the direction of the mouth, thereby producing an effect of preventing the natural mountain from rising.

  However, the ground is non-uniform, and even if it is managed by the above method, there is a possibility that a natural uplift, depression, or subsidence may actually occur. Therefore, the amount of deformation of the ground and the track is monitored with a wireless sensor and linked with the packer pressure control unit so that the packer pressure is unloaded before harmful deformation occurs. Thereby, it becomes possible to suppress the progress of deformation accompanying construction.

   (3) By reducing the deformation as much as possible when constructing the injection type ground reinforcement, the risk of raising the ground is reduced compared to the conventional method of expanding the ground and constructing the reinforcement. In particular, since the osmotic injection is performed in the gap so as not to disturb the skeleton of the soil particles on the ground as much as possible, the injection pressure also decreases and the deformation of the ground hardly occurs. Furthermore, since the construction cycle such as conventional repetitive injection can be reduced, the construction time can be reduced. In addition, since it is based on osmotic injection, the injection amount is also greatly reduced. As a result, the construction speed can be improved and the construction cost can be reduced.

  For example, in the case of railways, we are concerned about the impact on the railroad, and in the conventional ground reinforced earth construction method, the construction was done in time before the railroad business hours, but by using the means of the present invention, Since the risk of impact is reduced, construction is possible during business hours and construction time increases. Along with this, construction period and construction cost can be reduced.

It is a schematic diagram which shows the construction method of the injection | pouring type natural ground reinforcement which shows the Example of this invention. It is a schematic diagram which shows the ground deformation | transformation prevention countermeasure at the time of the injection construction by control of the packer pressure which shows the Example of this invention. It is explanatory drawing which shows an example of the grasping | ascertainment method of the injection pressure and the displacement amount which shows the Example of this invention. It is a control flowchart of the packer pressure which shows the Example of this invention. It is a schematic diagram which shows the conventional problem.

  The earthen structure reinforcement construction and quality control method using the injection type natural ground reinforcing material of the present invention is an earthing structure such as embankment or earth retaining wall near a railroad, road, house, etc. Reinforcement and quality of earth structures using injection-type ground reinforcement that reinforces while suppressing as much as possible the uplift of the natural ground or deformation of sinking or sinking during construction using reinforcement In the management method, the hole diameter is reduced.

  Hereinafter, embodiments of the present invention will be described in detail.

  The embodiment will be described by taking as an example the case of reinforcing an existing earth retaining wall.

  First, the construction method of the injection type natural ground reinforcement will be described with reference to FIG.

  FIG. 1 is a schematic view showing a construction method of an injection type natural ground reinforcing material according to an embodiment of the present invention.

  [A] Installation of the drilling / injection tube will be described.

    As shown to (a) of FIG. 1 (A), the casing 2 is provided in the retaining wall 1, and the drilling hole 4 for constructing an injection type natural ground reinforcement is formed in the casing 2 with the rod 3. As shown in FIG.

   (2) Next, as shown in FIG. 1 (A) (b), an injection pipe 5 is installed in the drilling hole 4 for the construction of the injection type ground reinforcement, and the injection material 6 is filled.

  (3) Next, an injection pipe (IP) 7 is installed in the hole 4 as shown in FIG.

  [B] Next, the ground injection procedure will be described.

  As shown in (a), (b), and (c) of FIG. [B], ground injection is performed.

  [C] Next, core material insertion and head fixing will be described.

  As shown in (a) and (b) of FIG. [C], the core material 8 is inserted, and the head portion 9 of the core material 8 is fixed.

  FIG. 2 is a schematic diagram showing a ground deformation prevention measure at the time of injection construction by controlling the packer pressure according to the embodiment of the present invention.

  As shown in this figure, ground deformation is applied while suppressing ground deformation and efficient infiltration. In particular, when construction is performed, the mouth packer 13 is separately provided in the hole drilling portion 12 at the mouth of the retaining wall 11 when approaching an important structure such as a track. Using this, the packer pressure of the mouth packer 13 is controlled as shown in FIG. 3 and FIG.

  FIG. 3 is an explanatory diagram showing an example of a method for grasping the injection pressure and the displacement amount according to the embodiment of the present invention, and FIG. 4 is a control flowchart of the packer pressure according to the embodiment of the present invention.

  In FIG. 3, 21 is a retaining wall, 22 is an injection tube, 23 is an injection hole, and 24 is a mouth packer.

  Concept: Injection is controlled based on the behavior when the mouth packer is pressurized.

  Outline: Since the physical properties of the embankment are not uniform, it is assumed that the allowable displacement exceeds the confining pressure, and the relationship between the confining pressure and the displacement assumed when closing the hole mouth drilled by the mouth packer And control values at the time of injection into each hole.

The procedure is as shown in FIG.
[1] Assumed constraint pressure (P ₁ ) at the mouth packer position P ₁ = W + γ _t × H ₁
In this equation, W: loading load, H ₁ : depth of mouth packer, H ₂ : depth of injection hole, P ₁ : pressure of mouth packer, P ₂ : pressure of injection hole, γ _t : unit volume mass of soil, δ ₁ : Displacement amount above the mouth packer, δ ₂ : Displacement amount above the injection hole [2] Displacement meter installation Multiple locations in the longitudinal and transverse directions [3] Mouth packer pressurization Packer pressurization up to the assumed restraint pressure [ 4] Displacement measurement When the allowable displacement amount (for example, 5 mm) is not reached: Packer pressurization is continued. When the allowable displacement amount (for example, 5 mm) is reached: Packer pressurization is terminated. [5] Restriction pressure specification (1) Mouth packer Pressurization (restraint pressure) (step S1)
(2) When the displacement amount δ ₁ is smaller than the allowable displacement amount 5 mm (displacement amount δ ₁ <5 mm), the restraint pressure is determined as the applied pressure (step S2).

(3) When the displacement amount δ ₁ is larger than the allowable displacement amount 5 mm (displacement amount δ ₁ ≧ 5 mm), the pressure is determined from the displacement amount (step S3).
[6] Therefore, two management items of ground deformation and injection pressure are set, and double quality and safety management is practiced. Specifically, an example of the management system is as follows.

  Two management items of ground deformation and injection pressure can be set to practice double quality and safety management. For example, when a natural mountain uplift occurs, the flow of the injection material is suppressed to suppress the natural mountain uplift. Further, when the ground is depressed or subsidized, the flow of the injection material is increased to prevent the ground from being depressed or subsidized.

  In addition, this invention is not limited to the said Example, Based on the meaning of this invention, a various deformation | transformation is possible and these are not excluded from the scope of the present invention.

  The earthen structure reinforcement construction and quality control method using the injection type natural ground reinforcement material of the present invention has an effect on important structures such as nearby tracks by suppressing the uplift, depression, and sinking of the natural ground as much as possible. It can be used as a method for reinforcing construction and quality control of earth structures using injection type ground reinforcement.

1,11,21 Retaining wall 2 Casing 3 Rod 4 Drilling hole 5,22 Injection pipe 6 Injection material 7 Injection pipe (IP)
8 Core Material 9 Core Material Head 12 Mouth Drilling Portion 13, 24 Mouth Packer 23 Injection Hole

Claims (5)

  When earth structures such as embankments and retaining retaining walls close to railway tracks, roads, houses, etc. are reinforced with injection-type earth-mount reinforcements, In an earthen structure reinforcement construction and quality control method using an injection-type ground reinforcement that reinforces while suppressing deformation as much as possible, an injection-type ground reinforcement that reduces the diameter of the drilling hole was used. Reinforcement and quality control methods for earth structures.   In the reinforcement construction and quality control method of the earth structure using the injection type natural ground reinforcing material according to claim 1, a packer is attached to a mouth portion of a drilling portion, and the packer pressure is related to the restraint pressure at the position. Reinforcement construction and quality control method of earth structure using injection type natural ground reinforcing material characterized by controlling   In the method of reinforcing construction and quality control of earth structures using the injection-type ground reinforcement according to claim 2, in the construction of the injection-type ground reinforcement, the track on the track surface or the road (pavement) surface Injection type characterized by constantly monitoring the vertical displacement, and if the displacement of the track or road (paved) surface may exceed the control value, immediately unload the packer pressure and leak the injected material from the mouth. Reinforcing and quality control methods for earth structures using natural ground reinforcement.   In the reinforcement construction and quality control method of the earth structure using the injection type natural ground reinforcing material according to claim 3, infiltrating and injecting into the gap of the ground in a small area (about 10 cm to 30 cm) around the injection pipe, A method for reinforcing construction and quality control of earth structures using injection-type ground reinforcements characterized by suppressing displacement.   In the method for reinforcing construction and quality control of earth structure using the injection type ground reinforcement according to claim 2, double quality and safety management are set by setting two control items of ground deformation and injection pressure. Reinforcement construction and quality control method of earth structure using injection type natural ground reinforcement material characterized by practicing.

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