JP7141326B2 - Structure construction method and bedrock protection method - Google Patents

Description

The present invention relates to a method for constructing a structure built on rock and a method for protecting rock.

When constructing a structure such as a dam body, in order to avoid the effects of crustal movements such as earthquakes and maintain the structure stably for a long period of time, the ground is excavated until the bedrock (foundation ground) is exposed, and then the bedrock is You can build structures on top of it. After excavating the ground to expose the bedrock and before constructing the structure, in order to suppress deterioration of the bedrock surface due to climate change such as rainfall and temperature changes, the bedrock surface is sprayed with mortar, for example. A covering method may be employed. Such a construction method is disclosed in Non-Patent Document 1.

Edited by Dam Technology Center, "Construction of Multi-Purpose Dam", 2005 Edition, Volume 6, Construction Edition

However, if the aforementioned structure is made of concrete and is to be attached to the bedrock surface, it is necessary to remove the aforementioned spray mortar prior to constructing the structure. In order to remove the sprayed mortar, it was necessary to manually remove the mortar using a breaker or pick hammer so as not to damage the bedrock surface. .

SUMMARY OF THE INVENTION In view of such circumstances, an object of the present invention is to reduce the work load when removing mortar or concrete covering the rock surface from the rock surface to protect the rock surface.

Therefore, in the first aspect of the present invention, as a method for constructing a structure, a spraying step of spraying thermally expandable particles and mortar or concrete onto a rock surface exposed to the outside, and hardened mortar or concrete on the rock surface A breaking step of breaking the hardened mortar or concrete by expanding it by heating the heat-expandable particles inside, a removing step of removing the broken mortar or concrete from the bedrock surface, and a removing step of removing the mortar or concrete. an excavation step of excavating the rock face to a predetermined thickness to form an excavation surface; and a construction step of constructing a structure on the excavation surface. Here, the mixing ratio of the thermally expandable particles to the mortar or concrete sprayed onto the rock surface increases as the rock surface approaches.

In a second aspect of the present invention, as a method of constructing a structure, a spraying step of spraying thermally expansive particles and mortar or concrete on a rock surface exposed to the outside, and hardening mortar or concrete on the rock surface A destruction step of destroying the hardened mortar or concrete by expanding by heating the thermally expansible particles of, a removal step of removing the destroyed mortar or concrete from the bedrock surface, and the mortar or concrete being removed and a building step of building the structure on the bedrock surface. Here, the mixing ratio of the thermally expandable particles to the mortar or concrete sprayed onto the rock surface increases as the rock surface approaches.

In the third aspect of the present invention, the method for protecting the rock includes a spraying step of spraying thermally expandable particles and mortar or concrete onto the exposed rock surface. It is possible to destroy the hardened mortar or concrete by expanding the thermally expandable particles in the hardened mortar or concrete on the bedrock surface by heating. Here, the mixing ratio of the thermally expandable particles to the mortar or concrete sprayed onto the rock surface increases as the rock surface approaches.

According to the invention, it is possible to destroy the hardened mortar or concrete by expanding the thermally expandable particles in the hardened mortar or concrete on the rock face by heating. As a result, the work using the aforementioned breaker, pick hammer, etc. can be greatly reduced, so that the work load when removing mortar or concrete from the bedrock surface can be reduced.

1 is a flow chart showing a method for constructing a dam body according to a first embodiment of the present invention; A diagram showing an excavation planning surface, a cover rock, a spray mortar, and a thermally conductive member in the first embodiment. Partially enlarged view of part P in FIG. A diagram showing an example of a mortar spraying method according to the first embodiment. Flowchart showing a method for constructing a dam body according to a second embodiment of the present invention A diagram showing an excavation plan surface, a first excavation surface, spray mortar, and a thermally conductive member in the second embodiment. The figure which shows arrangement|positioning of the thermally-conductive member in 3rd Embodiment of this invention. The figure which shows the heat conductive member in 4th Embodiment of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a flow chart showing a method for constructing a dam body according to the first embodiment of the present invention. FIG. 2 is a diagram showing an excavation plan, cover rock, spray mortar, and thermally conductive members.
In this embodiment, the method for constructing a structure according to the present invention will be described by taking the method for constructing a dam body as an example, but the structure according to the present invention is not limited to the dam body.
Further, in the present embodiment, the dam bank is made of concrete (that is, the dam bank is a concrete dam), but the configuration of the dam bank is not limited to this.

A dam body (not shown) is a hydraulic structure having a function of damming water.
The dam body is constructed on the bedrock after excavating the bedrock that serves as the foundation ground.

Excavation of this bedrock requires excavation of a large amount of soil and rocks in a short period of time, while it is necessary not to damage the bedrock in the vicinity of the excavation plan plane α. Therefore, generally, the excavation up to the excavation plan plane α is divided into rough excavation (step S1, which will be described later) and finish excavation (step S7, which will be described later).

As shown in FIG. 1, in the method for constructing a dam body, rough excavation of the ground (foundation excavation) is first performed in step S1. By this rough excavation, the first excavated surface 1, which is a bedrock surface (surface of foundation ground), is exposed to the outside. That is, the first excavated surface 1 is formed by excavating the ground.
In rough excavation, if the ground is hard rock, explosive excavation method using explosives is adopted, and if the ground is topsoil, soft rock, weathered rock, etc., mechanical excavation method using bulldozer, ripper, etc. is adopted. .

In the rough excavation, a bedrock of a predetermined thickness t1 is left up to the planned excavation plane α. That is, rough excavation is performed so that the distance (thickness) between the first excavation plane 1 and the planned excavation plane α becomes a predetermined thickness t1. Here, a portion of the bedrock corresponding to the predetermined thickness t1 is called a cover rock C. As shown in FIG. Further, the predetermined thickness t1 is preset so as to cover and protect the planned excavation plane α. The predetermined thickness t1 is, for example, approximately 50 cm.

Next, in step S2, a net-like thermally conductive member 3 is laid on the first excavation surface 1. As shown in FIG. The thermally conductive member 3 is, for example, a metallic mesh member. The thermally conductive member 3 can be, for example, any one of lath mesh, reticulated reinforcing bars, and expanded metal. Note that step S2 corresponds to the "laying step" of the present invention. Here, when the first excavation surface 1 is an inclined surface (slope), the thermally conductive member 3 can realize the function of preventing falling rocks from the first excavation surface 1 .

The thermally conductive member 3 has a plurality of exposed portions 4 exposed to the outside from a spray mortar 5, which will be described later. In this embodiment, the exposed portion 4 is configured by a reinforcing rod. The base end (lower end) of this reinforcing bar is connected to the thermally conductive member 3, penetrates the spray mortar 5, and at least the tip (upper end) can be exposed to the outside from the spray mortar 5.

The installation interval of the exposed portions 4 is appropriately set according to the amount of heat applied to the exposed portions 4 in step S<b>5 described later, and the thermal conductivity of the exposed portions 4 , the thermally conductive member 3 , and the spray mortar 5 . For example, the installation interval of the exposed portions 4 is about 1 m.

Next, in step S3, mortar is sprayed onto the first excavation surface 1 on which the thermally conductive member 3 is laid (that is, onto the portion of the first excavated surface 1 where the thermally conductive member 3 is laid). Thereby, the first excavation surface 1 is covered with the spray mortar 5 . Here, the thickness t2 of the spray mortar 5 is, for example, about 10 cm. Note that step S3 corresponds to the "spraying step" of the present invention.

Details of the "spraying process" in this embodiment will now be described with reference to FIGS. 3 and 4 in addition to FIGS. 1 and 2 described above.
FIG. 3 is a partially enlarged view of portion P of FIG. FIG. 4 is a diagram showing an example of a mortar spraying method according to this embodiment.

As shown in FIG. 3, in this embodiment, the spray mortar 5 has a two-layer structure consisting of a first layer 11 adjacent to the first excavation surface 1 and a second layer 12 laminated thereon. ing. The thickness t3 of the first layer 11 (the distance from the bottom surface to the top surface in contact with the first excavation surface 1) is, for example, about 3 cm. A thermally conductive member 3 is located within the first layer 11 . The first layer 11 corresponds to the range of the spray mortar 5 that can cover the thermally conductive member 3 .

In the first layer 11, thermally expandable particles are mixed in mortar. Here, the thermally expandable particles are formed including, for example, an outer shell made of a thermoplastic polymer and a volatile expanding agent included in the outer shell. As the volatile swelling agent, one formed from a low-boiling organic solvent is preferable. The thermally expandable particles preferably have an average particle size within the range of 1 μm to 100 μm, more preferably 5 μm to 70 μm. The thermally expandable particles preferably have an expansion start temperature (expansion start temperature) of 70° C. or higher. In other words, the thermally expandable particles preferably do not expand (foam) at temperatures below 70°C. This can prevent the thermally expandable particles from expanding due to weather changes or heat of hydration of cement. As the thermally expandable particles, for example, Matsumoto Microsphere (registered trademark) F and FN series manufactured by Matsumoto Yushi Pharmaceutical Co., Ltd., and Advancel (registered trademark) EM manufactured by Sekisui Chemical Co., Ltd. can be used. .
In the first layer 11, the volume ratio of mortar and thermally expandable particles is preferably within the range of 1:0.001 to 1:0.2.

In this embodiment, in the second layer 12, thermally expandable particles are not mixed in the mortar. Therefore, the mixing ratio of the thermally expandable particles to the spray mortar 5 is higher in the first layer 11 than in the second layer 12 . Therefore, the mixing ratio of the thermally expandable particles to the spray mortar 5 increases as the first excavation surface 1 is approached.

When forming the first layer 11 in the "spraying step" of the present embodiment, as shown in FIG. At the same time, thermally expandable particles are sprayed toward the thermally conductive member 3 and the first excavation surface 1 from the ejection port of the thermally expandable particle supply hose 16 .

On the other hand, when the second layer 12 is formed in the "spraying step" of the present embodiment, mortar is discharged from the outlet of the mortar supply hose 15 while the supply of the thermally expandable particles to the thermally expandable particle supply hose 16 is stopped. It is blown towards the thermally conductive member 3 and the first excavation surface 1 .

As described above, by dividing the spraying of mortar and the spraying of thermally expandable particles into separate systems, it is possible to switch whether to mix the thermally expandable particles with the mortar and to change the mixing ratio of the thermally expandable particles to the mortar. Changes can be easily made.
Further, in the preliminarily partitioned region of the inclined first excavation surface 1, following the operation of forming the first layer 11 mixed with the thermally expandable particles, the second layer 12 not mixed with the thermally expandable particles was formed. Since the forming work can be performed, the worker can perform the forming work of the first layer 11 and the forming work of the second layer 12 at once in the above-described partitioned area. Work on an inclined surface (slope) can be made significantly more efficient.

In this embodiment, the mortar and the thermally expandable particles are separately injected toward the thermally conductive member 3 and the first excavation surface 1. The mortar and the thermally expandable particles are mixed immediately before being jetted toward the conductive member 3 and the first excavation surface 1, and the mixed mortar and the thermally expandable particles are injected into the thermally conductive member 3 and the first excavation surface 1. You may make it inject toward the excavation surface 1 of .
After this "spraying step" the spray mortar 5 hardens.

Next, in step S4, basic processing is performed. In this basic processing, for example, construction of an inspection corridor is performed. In this basic treatment step, a neglect period of several months to several years may occur. When the basic treatment process is completed, the process proceeds to step S5.

In step S<b>5 , the heat conductive member 3 is heated by heating the exposed portion 4 on the surface 5 a of the spray mortar 5 . For example, a gas burner for asphalt pavement may be used to heat the exposed portion 4 . Alternatively, exhaust heat (exhaust gas) of the engine may be used to heat the exposed portion 4 . The surface 5a of the spray mortar 5 may be heated when the exposed portion 4 is heated.

The heat applied to the exposed portion 4 is transferred to the first layer 11 of the spray mortar 5 via the heat conductive member 3 . As a result, the thermally expandable particles in the first layer 11 are heated and expanded (foamed), causing cracks in the first layer 11 and the second layer 12 , and as a result, the spray mortar 5 becomes The first layer 11 and the second layer 12 are destroyed. At the time of this destruction, the adhesion between the spray mortar 5 and the first excavation surface 1 can be eliminated.
Note that step S5 corresponds to the "breaking step" of the present invention.

Next, in step S6, the destroyed spray mortar 5 is removed from the first excavation surface 1. As shown in FIG. Here, since the adhesion between the spray mortar 5 and the first excavation surface 1 can be eliminated in step S5 described above, the removal operation of the spray mortar 5 is facilitated. In addition, since the mixture of rock fragments into the removed spray mortar 5 is greatly suppressed, the amount of industrial waste output can be minimized.
Note that step S6 corresponds to the "removal step" of the present invention. In this “removal step” the thermally conductive member 3 is removed from the first excavation surface 1 .

Next, finish excavation is performed in step S7. In finish excavation, the cover lock C is removed to expose the planned excavation plane α to the outside. In other words, in step S7, the second excavated surface 2 is formed by excavating the first excavated surface 1 from which the spray mortar 5 has been removed by a predetermined thickness t1. Here, the second excavation plane 2 corresponds to the planned excavation plane α.

In finish excavation, careful excavation is performed by human power and breakers without using explosives.
Excavation muck generated in finish excavation can be used to construct embankments and the like.
Note that step S7 corresponds to the "excavation step" of the present invention.

Next, in step S8, the second excavation surface 2 is cleaned (bedrock cleaning). In this process, the second excavation surface 2 is washed with a water jet or the like to remove deposits and the like on the second excavation surface 2 in order to increase the adhesion between the concrete that constitutes the dam body and the bedrock. .

After completing the cleaning of the second excavation surface 2, a dam body is constructed in step S9. In this embodiment, the concrete forming the dam body is placed in step S9. This dam body is constructed on the second excavation surface 2 and adheres to the bedrock.
In this manner, the dam body is constructed.
Note that step S8 corresponds to the "construction step" of the present invention.

In the present embodiment, in step S9, a bank body of a concrete dam is constructed, but instead of this, a bank body of a fill dam may be constructed. When constructing the embankment of the fill dam in step S9, the soil and rocks constituting the dam embankment are built up in step S9.

In this embodiment, the first excavation surface 1 is covered with the spray mortar 5 by spraying mortar onto the first excavation surface 1. By spraying concrete, the first excavation face 1 may be covered with shotcrete. In this case, "mortar" should be read as "concrete" in the above description.

According to this embodiment, as a method for constructing a structure (dam body), a spraying step ( Step S3) and expanding the thermally expandable particles by heating them in the hardened mortar or concrete (shot mortar 5 or shotcrete) on the bedrock surface (first excavation surface 1); By doing so, a destruction step (step S5) of destroying the hardened mortar or concrete (the shot mortar 5 or the shot concrete), and the destroyed mortar or concrete (the shot mortar 5 or the shot concrete) are removed from the bedrock surface (the first excavation surface 1) is removed (step S6), and the bedrock surface (first excavation surface 1) from which the mortar or concrete (the shot mortar 5 or the shot concrete) has been removed is excavated by a predetermined thickness t1 to excavate the excavated surface. An excavation step (step S7) of forming (second excavation surface 2) and a construction step (step S9) of constructing a structure (dam body) on the excavation surface (second excavation surface 2). include. As a result, the work using the aforementioned breaker, pick hammer, etc. can be greatly reduced, so the work load when removing mortar or concrete from the bedrock surface (first excavation surface 1) can be reduced. . In addition, it is possible to prevent unnecessary loosening of the bedrock deeper than the bedrock surface (first excavation surface 1).

Further, according to the present embodiment, the construction method of the structure (dam body) includes laying the net-like thermally conductive member 3 on the bedrock surface (first excavation surface 1) prior to the spraying step (step S3). It further includes a laying step (step S2). In the destruction step (step S5), by heating the thermally conductive member 3, the thermal expansibility in the hardened mortar or concrete (shot mortar 5 or shot concrete) on the bedrock surface (first excavation surface 1) Heat the particles. Thereby, the thermally expandable particles distributed over a wide range in the first layer 11 can be efficiently heated.

Further, according to the present embodiment, the thermally conductive member 3 has the exposed portion 4 exposed to the outside from the mortar or concrete (shot mortar 5 or shot concrete) sprayed on the bedrock surface (first excavation surface 1). . In the destruction step (step S5), the heat conductive member 3 is heated by heating the exposed portion 4. As shown in FIG. Thereby, the heat conductive member 3 can be easily heated via the exposed portion 4 .

Further, according to the present embodiment, the area (first layer 11) is adjacent to the bedrock surface (first excavation surface 1) and is in contact with the thermally conductive member 3; As a result, adhesion between the bedrock surface (first excavation surface 1) and the shot mortar 5 or shot concrete can be reliably eliminated.

Further, according to the present embodiment, the mixing ratio of the thermally expandable particles to the mortar or concrete (shot mortar 5 or shot concrete) sprayed on the rock surface (first excavation surface 1) is The closer it gets to surface 1), the higher it gets. Therefore, adhesion between the bedrock surface (first excavation surface 1) and the shot mortar 5 or shot concrete can be reliably eliminated.

Further, according to the present embodiment, the expansion start temperature of the thermally expandable particles is 70° C. or higher. This can prevent the thermally expandable particles from expanding due to weather changes or heat of hydration of cement.

Further, in this embodiment, the thermally expandable particles are preferably colored in a color (for example, red, orange, pink, etc.) that stands out against the mortar or concrete (the shot mortar 5 or the shot concrete). By doing so, the uniformity of the mixture of the thermally expandable particles in the first layer 11, the mixture ratio, and the like can be easily visually recognized by the operator during the spraying operation. In addition, the operator can easily see whether or not the thermally expandable particles are being jetted from the nozzle of the thermally expandable particle supply hose 16 .

Further, according to this embodiment, the bedrock surface (first excavation surface 1) is an excavation surface formed by excavating the ground (step S1). The structure (dam body) is made of concrete. As a result, the concrete forming the structure (dam body) and the bedrock can be watertightly adhered to each other.

Further, according to this embodiment, the structure constructed according to the flow chart shown in FIG. 1 is a hydraulic structure (dam body). As a result, the bedrock can stably support the hydraulic structure (dam body) while the hydraulic structure (dam body) and the bedrock are in watertight contact.

Further, according to the present embodiment, the method for protecting the bedrock includes a spraying step (step S3) of spraying thermally expansive particles and mortar or concrete onto the exposed bedrock surface (first excavation surface 1). . By heating the thermally expandable particles in the hardened mortar or concrete (shot mortar 5 or shot concrete) on the bedrock surface (first excavation surface 1), the hardened It is possible to destroy mortar or concrete (shot mortar 5 or shot concrete). As a result, the work using the aforementioned breaker, pick hammer, etc. can be greatly reduced, so the work load when removing mortar or concrete from the bedrock surface (first excavation surface 1) can be reduced. .

Further, according to the present embodiment, the method for protecting the bedrock includes the laying step (step S2 ) further includes. By heating the thermally conductive member 3, it is possible to heat the thermally expandable particles in the hardened mortar or concrete (shot mortar 5 or shot concrete) on the bedrock surface (first excavation surface 1). be. Therefore, the thermally expandable particles distributed over a wide range in the first layer 11 can be efficiently heated.

Further, according to the present embodiment, it is possible to heat the thermally conductive member 3 by heating the exposed portion 4 . Thereby, the heat conductive member 3 can be easily heated via the exposed portion 4 .

Next, a first modified example and a second modified example of this embodiment will be described.

In the first modification of the present embodiment, thermally expandable particles are mixed in mortar for the second layer 12 as well as for the first layer 11 . By doing so, it is possible to easily destroy the second layer 12 in the aforementioned "destruction step". In this modified example, in the "spraying process" described above, the mortar mixed with the thermally expansive particles in advance is conveyed by the mortar supply hose 15, and the thermally conductive member 3 and the first excavation surface 1 are discharged from the ejection port of the mortar supply hose 15. You may form the 1st layer 11 and the 2nd layer 12 continuously by spraying toward . That is, there may be only one material supply system for spraying.

In the second modified example of the present embodiment, the heat conductive member 3 and the exposed portion 4 are omitted from the first modified example described above. In this variant, the surface 5a of the spray mortar 5 can be heated in the aforementioned "breaking step".

It goes without saying that "mortar" can also be read as "concrete" in the description of the first and second modifications.

FIG. 5 is a flow chart showing a method for constructing a dam body according to the second embodiment of the present invention. FIG. 6 is a diagram showing the planned excavation plane, the first excavation plane, the spray mortar, and the thermally conductive member.
Differences from the first embodiment shown in FIGS. 1 to 4 will be described.

In the present embodiment, the dam body is assumed to be a fill dam body, but the configuration of the dam body is not limited to this.

In the first embodiment described above, excavation up to the excavation plan plane α is divided into rough excavation (step S1) and finish excavation (step S7). , step S11 shown in FIG.

In step S11, the ground is excavated. As a result of this excavation, a first excavated surface 1 (see FIG. 6), which is a bedrock surface (surface of foundation ground), is exposed to the outside. That is, the first excavated surface 1 is formed by excavating the ground. Here, the first excavation plane 1 corresponds to the planned excavation plane α.

Step S11 and subsequent steps are the same as the flow chart shown in FIG. 1 in the above-described first embodiment, except that step S7 is omitted.
Here, in the present embodiment, cleaning of the first excavation surface 1 (bedrock cleaning) is performed in step S8. Further, in step S9, the soil and rocks forming the dam body are heaped up. This dam bank is constructed on the first excavation surface 1 .

In the present embodiment, the embankment of the fill dam is constructed in step S9, but instead of this, the embankment of the concrete dam may be constructed. When constructing the embankment of the concrete dam in step S9, the concrete forming the embankment of the dam is placed in step S9.

In particular, according to this embodiment, as a method of constructing a structure (dam body), a spraying step of spraying thermally expandable particles and mortar or concrete onto a rock surface (first excavation surface 1) exposed to the outside. (Step S3) and expanding the thermally expandable particles by heating the thermally expandable particles in the hardened mortar or concrete (shot mortar 5 or shot concrete) on the bedrock surface (first excavation surface 1). A destruction step (step S5) for destroying the hardened mortar or concrete (the shot mortar 5 or the shot concrete), and the destroyed mortar or concrete (the shot mortar 5 or the shot concrete) is removed from the bedrock surface (the first excavation A removal step (step S6) of removing from surface 1) and constructing a structure (dam bank body) on the bedrock surface (first excavation surface 1) from which mortar or concrete (shot mortar 5 or shot concrete) has been removed and a building step (step S9). As a result, the work using the aforementioned breaker, pick hammer, etc. can be greatly reduced, so the work load when removing mortar or concrete from the bedrock surface (first excavation surface 1) can be reduced. . In addition, it is possible to prevent unnecessary loosening of the bedrock deeper than the bedrock surface (first excavation surface 1).

It goes without saying that the above-described first modified example and second modified example can be applied to the present embodiment.

Next, a third embodiment of the invention will be described with reference to FIG.
FIG. 7 is a diagram showing the arrangement of thermally conductive members in this embodiment. Specifically, after the above-mentioned "laying process" and before the "spraying process", two adjacent thermal conductive A portion of the members 3-1 and 3-2 is shown.
This embodiment can be applied to both the above-described first embodiment and second embodiment (including the above-described first modification).

In this embodiment, when constructing the dam bank in stages (for example, when constructing the dam bank by repeating the construction of a predetermined lift height), the steps S5 to S9 described above are performed for each step. As practicable, the thermally conductive member 3 is divided to correspond to each stage. In this respect, the thermally conductive members 3-1 and 3-2 described above correspond to divided portions (divided portions) of the thermally conductive member 3. As shown in FIG. The shape of the split portions of the thermally conductive member 3 (for example thermally conductive members 3-1, 3-2) corresponds to the shape of the area of the shot mortar 5 (or shot concrete) that is destroyed in each stage.

As shown in FIG. 7, a space 20 is provided between the split portions of the thermally conductive member 3 (for example, between the thermally conductive members 3-1 and 3-2). The distance D1 of this interval 20 is, for example, about 5 cm to 20 cm.

For example, even if the region of the shot mortar 5 (or shot concrete) containing the thermally conductive member 3-1 is destroyed in the above-described “breaking step”, the presence of the space 20 allows the shot mortar 5 (or shot concrete) ) including the thermally conductive member 3-2 is not destroyed. In this way, the removal area of the shot mortar 5 (or shot concrete) can be limited.

Next, a fourth embodiment of the invention will be described with reference to FIG.
FIG. 8 is a diagram showing a thermally conductive member in this embodiment.
This embodiment can be applied to the first to third embodiments described above (including the first modified example described above).

In this embodiment, the first excavation surface 1 is serrated and has a plurality of recesses 1a. The depth of the recess 1a is, for example, about 5 cm. Thermally expandable particles and mortar (or concrete) having the same mixing ratio as the first layer 11 are also sprayed and filled in the recess 1a.

In this embodiment, in order to effectively transmit the heat transmitted from the exposed portion 4 to the thermally conductive member 3 in the above-described "destruction step" to the thermally expandable particles and mortar (or concrete) in the recess 1a, a metallic material is used. A rod-shaped thermally conductive member 18 is installed. The thermally conductive member 18 is, for example, a reinforcing bar. The base end (upper end) of the thermally conductive member 18 is connected to the thermally conductive member 3, and the tip (lower end) faces the bottom (bottom) of the recess 1a.

When laying the thermally conductive member 3 on the first excavated surface 1, if a large gap is formed between the first excavated surface 1 and the thermally conductive member 3, the spray is applied to the gap. In order to conduct heat from the thermally conductive member 3 well to the thermally expansive particles and mortar (or concrete) filled in the gap, the thermally conductive member 18 or the like is placed in the gap. It is preferably provided on the member 3 .

Next, a fifth embodiment of the present invention will be described.
Differences from the first to fourth embodiments described above will be described.

In the first to fourth embodiments described above, mortar (or concrete) and thermally expandable particles are simultaneously sprayed onto the thermally conductive member 3 and the first excavation surface 1 .
In contrast, in the present embodiment, prior to spraying mortar (or concrete) onto the thermally conductive member 3 and the first excavation surface 1, the thermally expandable particles are adhered to the thermally conductive member 3 with an adhesive or the like. , mortar (or concrete) is sprayed toward the thermally conductive member 3 to which the thermally expandable particles are adhered and the first excavation surface 1 .

In particular, according to this embodiment, as a method of constructing a structure (dam body), a bonding step of bonding thermally expandable particles to a net-like thermally conductive member 3, and a rock surface exposed to the outside (first excavation A laying step of laying the thermally conductive member 3 on the surface 1), a spraying step of spraying mortar or concrete on the bedrock surface (first excavation surface 1) on which the thermally conductive member 3 is laid, By heating the member 3, the thermally expandable particles adhered to the thermally conductive member 3 are heated to expand the thermally expandable particles. A destruction step of destroying hardened mortar or concrete (shot mortar 5 or shot concrete), and a removal step of removing the destroyed mortar or concrete (shot mortar 5 or shot concrete) from the bedrock surface (first excavation surface 1). Then, the bedrock surface (first excavation surface 1) from which the mortar or concrete (the shot mortar 5 or the shot concrete) has been removed is excavated by a predetermined thickness t1 to form an excavation surface (second excavation surface 2). It includes an excavation step and a construction step of constructing a structure (dam body) on the excavation surface (second excavation surface 2). As a result, the work using the aforementioned breaker, pick hammer, etc. can be greatly reduced, so the work load when removing mortar or concrete from the bedrock surface (first excavation surface 1) can be reduced. . In addition, it is possible to prevent unnecessary loosening of the bedrock deeper than the bedrock surface (first excavation surface 1).

Further, according to the present embodiment, as a method of constructing a structure (dam body), a bonding step of bonding thermally expansible particles to a net-like thermally conductive member 3, and a rock surface exposed to the outside (first excavation A laying step of laying the thermally conductive member 3 on the surface 1), a spraying step of spraying mortar or concrete on the bedrock surface (first excavation surface 1) on which the thermally conductive member 3 is laid, By heating the member 3, the thermally expandable particles adhered to the thermally conductive member 3 are heated to expand the thermally expandable particles. A destruction step of destroying hardened mortar or concrete (shot mortar 5 or shot concrete), and a removal step of removing the destroyed mortar or concrete (shot mortar 5 or shot concrete) from the bedrock surface (first excavation surface 1). and a construction step of constructing a structure (dam body) on the bedrock surface (first excavation surface 1) from which mortar or concrete (shot mortar 5 or shot concrete) has been removed. As a result, the work using the aforementioned breaker, pick hammer, etc. can be greatly reduced, so the work load when removing mortar or concrete from the bedrock surface (first excavation surface 1) can be reduced. . In addition, it is possible to prevent unnecessary loosening of the bedrock deeper than the bedrock surface (first excavation surface 1).

Further, according to the present embodiment, as a method for protecting the bedrock, a bonding step of bonding the thermally expandable particles to the net-like thermally conductive member 3, and a thermal It includes a laying step of laying the conductive member 3 and a spraying step of spraying mortar or concrete onto the bedrock surface (first excavation surface 1) on which the thermally conductive member 3 is laid. By heating the thermally conductive member 3, the thermally expandable particles adhered to the thermally conductive member 3 are heated to expand the thermally expandable particles, thereby forming a bedrock surface (first excavation surface 1). It is possible to destroy hardened mortar or concrete (shot mortar 5 or shot concrete) on top. As a result, the work using the aforementioned breaker, pick hammer, etc. can be greatly reduced, so the work load when removing mortar or concrete from the bedrock surface (first excavation surface 1) can be reduced. .

The above-mentioned "adhesion process" may be performed before the above-described "laying process" or may be performed after the above-mentioned "laying process". Alternatively, the "bonding step" described above may be performed during the "laying process" described above (in other words, in parallel with the "laying process" described above). That is, the above-mentioned "adhesion process" can be performed at any time before the above-mentioned "spraying process". Considering the improvement of work efficiency at the site, it is preferable that the above-mentioned "adhesion process" is performed before the above-mentioned "laying process".

In this embodiment, it goes without saying that mortar (or concrete) and thermally expandable particles may be simultaneously sprayed onto the thermally conductive member 3 and the first excavation surface 1 to which the thermally expandable particles are adhered. In this case, the thermally expandable particles may be mixed only in the mortar (or concrete) of the first layer 11, or the mortar (or concrete) of both the first layer 11 and the second layer 12 may contain thermally expandable particles. particles may be mixed.

In the first to fifth embodiments described above, the exposed portion 4 is composed of a reinforcing bar, but the configuration of the exposed portion 4 is not limited to this. For example, a portion of the thermally conductive member 3 exposed to the outside by scraping off a portion of the shot mortar 5 (or shot concrete) may be used as the exposed portion 4 . Alternatively, the exposed portion 4 may be composed of a metal mesh member (for example, lath mesh, mesh reinforcing bars, or expanded metal). When the exposed portion 4 is made of a metal mesh member, one side of the exposed portion 4 is connected to the thermally conductive member 3, and the other side can be exposed to the outside from the sprayed mortar 5 (or sprayed concrete).

In the above-described first to fifth embodiments, at least one of mortar (or concrete) and thermally expandable particles is mixed with thermally conductive powder such as iron powder, and the mixture is subjected to the first By spraying the excavation surface 1, the thermal conductivity of the spray mortar 5 (or the spray concrete) can be improved.

In the above-described first to fifth embodiments, the method for constructing a dam body was described as an example of the method for constructing a hydraulic structure according to the present invention. is not limited to For example, the hydraulic structure may be the body of a sluice built on a rock face. Moreover, the structure to which the method for constructing a structure according to the present invention is applied is not limited to the hydraulic structure described above, and may be, for example, a structure such as a nuclear power plant or a bridge pier foundation.

Further, in the first to fifth embodiments described above, the rock protection method according to the present invention has been described by taking as an example the method for protecting the rock that serves as the foundation ground of the dam body. The rock mass to which the protection method can be applied is not limited to this. In order to prevent the excavation surface from being exposed to the outside for a long period of time, the excavation surface is temporarily treated, and after the elapse of the period, a new structure is constructed on the excavation surface. The rock mass protection method according to the present invention can be applied. For example, the rock protection method according to the present invention can be applied to protection of rocks intended to support structures such as nuclear power plants and bridge pier foundations.

Further, the illustrated embodiments are merely examples of the present invention, and the present invention is not only directly indicated by the described embodiments, but also includes various modifications and improvements made by those skilled in the art within the scope of the claims. It goes without saying that changes are included.
The claims as originally filed were as follows.
[Claim 1]
A spraying step of spraying thermally expandable particles and mortar or concrete onto the rock surface exposed to the outside;
a breaking step of breaking the hardened mortar or concrete on the bedrock surface by expanding the thermally expandable particles in the hardened mortar or concrete by heating;
a removing step of removing the destroyed mortar or concrete from the bedrock surface;
an excavation step of excavating the rock surface from which the mortar or concrete has been removed to a predetermined thickness to form an excavated surface;
a building step of building a structure on the excavation surface;
A method of constructing a structure, including
[Claim 2]
A spraying step of spraying thermally expandable particles and mortar or concrete onto the rock surface exposed to the outside;
a breaking step of breaking the hardened mortar or concrete on the bedrock surface by expanding the thermally expandable particles in the hardened mortar or concrete by heating;
a removing step of removing the destroyed mortar or concrete from the bedrock surface;
a building step of building a structure on the bedrock surface from which the mortar or concrete has been removed;
A method of constructing a structure, including
[Claim 3]
Further comprising a laying step of laying a net-like thermally conductive member on the rock surface prior to the spraying step,
3. The method according to claim 1, wherein in the breaking step, the heat-expandable particles in the hardened mortar or concrete on the bedrock surface are heated by heating the thermally conductive member. construction method of structures.
[Claim 4]
The thermally conductive member has an exposed portion exposed to the outside from the mortar or the concrete sprayed on the rock surface,
4. The method of constructing a structure according to claim 3, wherein in said breaking step, said thermally conductive member is heated by heating said exposed portion.
[Claim 5]
A region of the mortar or concrete sprayed onto the bedrock surface, in which the thermally expandable particles are mixed, is adjacent to the bedrock surface and in contact with the thermally conductive member; A method for constructing a structure according to claim 3 or 4.
[Claim 6]
The structure according to any one of claims 1 to 5, wherein a mixing ratio of the thermally expandable particles to the mortar or the concrete sprayed onto the rock surface increases toward the rock surface. How things are built.
[Claim 7]
The method for constructing a structure according to any one of claims 1 to 6, wherein the thermally expandable particles have an expansion initiation temperature of 70°C or higher.
[Claim 8]
The structure construction method according to any one of claims 1 to 7, wherein the thermally expandable particles are colored in a color that stands out against the mortar or the concrete.
[Claim 9]
Including a spraying step of spraying thermally expandable particles and mortar or concrete on the rock surface exposed to the outside,
Protection of rock mass, wherein the thermally expandable particles in the hardened mortar or concrete on the rock face can be broken by heating to expand the hardened mortar or concrete. Method.
[Claim 10]
Further comprising a laying step of laying a net-like thermally conductive member on the rock surface prior to the spraying step,
10. Rock protection according to claim 9, wherein it is possible to heat the thermally expandable particles in the hardened mortar or concrete on the rock surface by heating the thermally conductive member. Method.
[Claim 11]
The thermally conductive member has an exposed portion exposed to the outside from the mortar or the concrete sprayed on the rock surface,
11. The rock protection method according to claim 10, wherein the thermally conductive member can be heated by heating the exposed portion.
[Claim 12]
A region of the mortar or the concrete sprayed onto the bedrock surface, in which the thermally expandable particles are mixed, is adjacent to the bedrock surface and is in contact with the thermally conductive member; The rock protection method according to claim 10 or 11.
[Claim 13]
13. The bedrock according to any one of claims 9 to 12, wherein a mixing ratio of the thermally expandable particles to the mortar or the concrete sprayed onto the bedrock surface increases toward the rock surface. protection method.
[Claim 14]
The rock protection method according to any one of claims 9 to 13, wherein the thermally expandable particles have an expansion start temperature of 70°C or higher.
[Claim 15]
The rock protection method according to any one of claims 9 to 14, wherein the thermally expandable particles are colored in a color that stands out against the mortar or the concrete.

1 first excavation surface 1a recess 2 second excavation surface 3, 3-1, 3-2 thermally conductive member 4 exposed portion 5 spray mortar 5a surface 11 first layer 12 second layer 15 mortar supply hose 16 thermal expansion particle supply hose 18 heat conductive member 20 interval C cover lock α excavation plan surface

Claims (13)

A spraying step of spraying thermally expandable particles and mortar or concrete onto the rock surface exposed to the outside;
a breaking step of breaking the hardened mortar or concrete on the bedrock surface by expanding the thermally expandable particles in the hardened mortar or concrete by heating;
a removing step of removing the destroyed mortar or concrete from the bedrock surface;
an excavation step of excavating the rock surface from which the mortar or concrete has been removed to a predetermined thickness to form an excavated surface;
a building step of building a structure on the excavation surface;
including
A method of constructing a structure, wherein a mixing ratio of the thermally expandable particles to the mortar or the concrete sprayed onto the rock surface increases as the rock surface approaches the rock surface . A spraying step of spraying thermally expandable particles and mortar or concrete onto the rock surface exposed to the outside;
a breaking step of breaking the hardened mortar or concrete on the bedrock surface by expanding the thermally expandable particles in the hardened mortar or concrete by heating;
a removing step of removing the destroyed mortar or concrete from the bedrock surface;
a building step of building a structure on the bedrock surface from which the mortar or concrete has been removed;
including
A method of constructing a structure, wherein a mixing ratio of the thermally expandable particles to the mortar or the concrete sprayed onto the rock surface increases as the rock surface approaches the rock surface . Further comprising a laying step of laying a net-like thermally conductive member on the rock surface prior to the spraying step,
3. The method according to claim 1, wherein in the breaking step, the heat-expandable particles in the hardened mortar or concrete on the bedrock surface are heated by heating the thermally conductive member. construction method of structures. The thermally conductive member has an exposed portion exposed to the outside from the mortar or the concrete sprayed on the rock surface,
4. The method of constructing a structure according to claim 3, wherein in said breaking step, said thermally conductive member is heated by heating said exposed portion. A region of the mortar or concrete sprayed onto the bedrock surface, in which the thermally expandable particles are mixed, is adjacent to the bedrock surface and in contact with the thermally conductive member; A method for constructing a structure according to claim 3 or 4. The method of constructing a structure according to any one of claims 1 to 5 , wherein the thermally expandable particles have an expansion initiation temperature of 70°C or higher. The structure construction method according to any one of claims 1 to 6 , wherein the thermally expandable particles are colored in a color that stands out against the mortar or the concrete. Including a spraying step of spraying thermally expandable particles and mortar or concrete on the rock surface exposed to the outside,
It is possible to destroy the hardened mortar or concrete by expanding the thermally expandable particles in the hardened mortar or concrete on the rock face by heating ,
A method for protecting a bedrock , wherein a mixing ratio of the thermally expandable particles to the mortar or the concrete sprayed onto the bedrock surface increases as the bedrock surface is approached . Further comprising a laying step of laying a net-like thermally conductive member on the rock surface prior to the spraying step,
9. Rock protection according to claim 8 , wherein it is possible to heat the thermally expandable particles in the hardened mortar or concrete on the rock face by heating the thermally conductive member. Method. The thermally conductive member has an exposed portion exposed to the outside from the mortar or the concrete sprayed on the rock surface,
10. The rock protection method according to claim 9 , wherein the thermally conductive member can be heated by heating the exposed portion. A region of the mortar or concrete sprayed onto the bedrock surface, in which the thermally expandable particles are mixed, is adjacent to the bedrock surface and in contact with the thermally conductive member; The rock protection method according to claim 9 or 10 . The rock protection method according to any one of claims 8 to 11 , wherein the thermally expandable particles have an expansion start temperature of 70°C or higher. The rock protection method according to any one of claims 8 to 12 , wherein the thermally expandable particles are colored in a color that stands out against the mortar or the concrete.

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