JP5218004B2 - Well and construction method of well - Google Patents

Description

  The present invention relates to a method of using a construction well constructed for draining groundwater as a well capable of taking groundwater after completion of construction when excavating the ground by an open-cut method.

Conventionally, when excavating the ground by the open-cut method, a construction well is constructed to drain the water and pump the groundwater to lower the groundwater level.
For example, Patent Document 1 discloses a method in which a casing pipe having a strainer is installed in a well, and groundwater collected in the casing pipe through the strainer is pumped by a pump to reduce groundwater in the ground. Has been.
JP-A-6-101236

  However, the well described in Patent Document 1 has a problem in that a power supply facility must be provided near the well because a pump is used to pump up groundwater. Moreover, the pump has a problem that it may be damaged if sand or pebbles are mixed in the groundwater.

  Therefore, the present invention has been made in view of the conventional problems as described above, and uses the power of a pump or the like when the construction well constructed for draining water is used even after the construction is completed. The purpose is to provide a well that can take underground water and its construction method.

  In order to achieve the above-mentioned object, the well of the present invention is a well constructed using holes provided for taking underground water around the underground structure when constructing the underground structure, A pipe installed inside to collect groundwater, a side of the pipe at a depth deeper than the head of the groundwater, and a water intake for taking groundwater in the pipe, and connected to the water intake And a water supply pipe for supplying the groundwater in the pipe to a predetermined place.

  According to the well of the present invention, since the water intake is provided at a depth deeper than the head of groundwater having pressure such as pressurized groundwater, water is supplied from the water intake due to the water head difference. Therefore, even if there is no power of a pump etc., groundwater can be taken in from a water intake and can be sent to a predetermined place via a water pipe. In addition, since there is no need to install equipment such as a power supply on the ground, the ground can be used effectively.

  Moreover, in this invention, if it shall be provided with the valve | bulb for adjusting the amount of water which passes the inside of the said water supply pipe | tube, water supply amount can be adjusted.

  Moreover, in this invention, if it shall be provided with the water storage tank for storing the groundwater taken from the said water intake, the groundwater taken can be stored.

  In the present invention, if the water pipe is buried in the ground and the water tank is installed in an underground structure, there is no need to install a pipe or a water tank on the ground. Can be used.

  Further, in the present invention, if a plurality of the intakes are provided at different depths along the longitudinal direction of the pipe, even if the water head of the groundwater rises or falls due to daily fluctuation or seasonal fluctuation, at least the intake opening Since any one of these exists at a depth deeper than the head of the groundwater, the groundwater can be taken.

  In the present invention, if the tube is provided with a lid at the upper end, the groundwater does not come into contact with the air, so that iron in the groundwater is not oxidized or adversely affects the ecology of microorganisms. Therefore, the well can be used for a long time.

  Moreover, in this invention, if the said pipe | tube, the said water supply pipe | tube, and the said cover consist of a material which has corrosion resistance, corrosion, such as rust, will not arise. Therefore, the well can be used for a long time.

  Further, in the present invention, if the hole is provided in the underground structure, it is not necessary to newly provide a space for installing a well, so that the periphery of the underground structure can be used effectively. .

  Further, in the present invention, if one end of the water pipe is installed so as to protrude from the underground structure, it is not necessary to newly provide a space for installing the water pipe. Can be used.

  Furthermore, in the present invention, the hole is provided in the vicinity of a planned construction location of the underground structure, and is provided in a retaining wall for preventing inflow of groundwater and earth and sand to the planned construction location. Good. If it does in this way, in building an underground structure, the hole built in the retaining wall can be used as it is for the purpose of lowering the groundwater level.

  Further, the method for constructing a well according to the present invention is a method for constructing a well by using a hole provided for taking underground water around the underground structure. A pipe installation step of installing a pipe capable of collecting water in the hole, an opening step of providing a water intake for taking groundwater in the pipe on the side surface of the pipe at a depth deeper than the head of groundwater, and A connection step of connecting a water supply pipe for supplying the groundwater in the pipe to a predetermined place to the intake port.

  According to the well construction method of the present invention, since the intake is provided at a depth deeper than the head of groundwater, water is supplied from the intake due to the difference in water head. Therefore, even if there is no power of a pump etc., groundwater can be taken in from a water intake and can be sent to a predetermined place via a water pipe. In addition, since there is no need to install equipment such as a power supply on the ground, the ground can be used effectively.

  According to the present invention, a construction well constructed for draining water can be used as a well without using power such as a pump.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, although the following embodiment demonstrates the case where a well is built in the soil-cement column wall which is a retaining wall, this invention is applied also when installing a well in retaining walls, such as RC. Can do.

FIG. 1 is a perspective view showing a state in which a well 1 according to an embodiment of the present invention is installed in a soil cement column wall 2.
As shown in FIG. 1, the soil cement column wall 2 is constructed so as to surround the surrounding construction site 4 of the underground structure 3 when the underground structure 3 (not shown) is constructed, and its lower end is the surface layer. It is installed so as to pass through 5 and reach the upper part of the clay layer 6 which is an impermeable layer.

FIG. 2 is a longitudinal sectional view showing a state in which the well 1 according to the present embodiment is installed in the soil cement column wall 2.
As shown in FIG. 2, in the soil cement column wall 2, there are holes 8 that are drilled as construction wells when the underground structure 3 is constructed. The holes 8 penetrate the soil cement column wall 2 in the depth direction and reach the lower end of the sand layer 7.

  The well 1 is installed in the hole 8, and a plurality of water collecting pipes 9 that can collect groundwater under pressure inside are provided, and a plurality of water collecting pipes 9 are provided on the side surfaces of the water collecting pipes 9 to take in the groundwater in the water collecting pipes 9. The water intakes 10a to 10c are connected to the water intakes 10a to 10c, respectively, and pass through the water supply pipes 11a to 11c for supplying the underground water in the water collection pipe 9 to the water storage tank 22 and the water supply pipes 11a to 11c. Open / close valves 12a to 12c for adjusting the amount of water are provided.

  The groundwater stored in the water storage tank 22 is used for various purposes in the underground structure 3 after construction.

  The water collecting pipe 9 is made of a corrosion-resistant material, for example, stainless steel, is inserted through the hole 8, penetrates the soil cement column wall 2 in the depth direction, and its lower end is the lower end of the soil cement column wall 2. It is installed so as to protrude from the bottom and reach the bottom of the hole 8.

  Around the lower end portion of the water collecting pipe 9 below the soil cement column wall 2, a filter portion 13 filled with sand for allowing groundwater to pass therethrough is provided on the upper side of the filter portion 13. A bentonite portion 14 filled with bentonite for preventing the passed groundwater from moving upward is formed.

  The filter portion 13 is provided in the sand layer 7 portion around the water collection pipe 9, and the bentonite portion 14 is provided in the clay layer 6 portion and the soil cement column wall 2 around the water collection tube 9.

  The water collecting pipe 9 in the sand layer 7 portion is provided with a screen 16 so that the ground water can flow into the pipe, and the ground water that has passed through the filter portion 13 flows into the water collecting pipe 9 through the screen 16. Since the water collecting pipe 9 does not corrode such as rust even when it comes into contact with groundwater, the water collecting pipe 9 can be used for a long time.

  A cap 18 is attached to the upper end surface of the water collecting pipe 9 to prevent air from entering and leaving the water collecting pipe 9 and outside. Screws are respectively cut at the outer peripheral lower end portion of the cap 18 and the inner peripheral upper end portion of the water collecting pipe 9, and the cap 18 is attached by being screwed into the water collecting pipe 9. In addition, an O-ring 19 is attached to the threaded portion of the cap 18, whereby the movement of air between the inside and the outside of the water collecting pipe 9 can be prevented while being attached to the water collecting pipe 9. In the present embodiment, the cap 18 is made of stainless steel.

  A plurality of intakes 10 a to 10 c are provided at different depths along the longitudinal direction of the water collection pipe 9. Water intake pipes 11a to 11c are connected to the water intakes 10a to 10c, respectively, and these water supply pipes 11a to 11c are provided so as to penetrate the soil cement column wall 2 and the wall surface of the underground structure 3. . Moreover, these water pipes 11a-11c are gathered together, are connected to the water storage tank 22 in the underground structure 3, and the ground water taken from each water intake 10a-10c passes each water pipe 11a-11c. It is supplied to the water storage tank 22. Furthermore, since the open / close valves 12a to 12c are attached to the water pipes 11a to 11c, the flow rate of the groundwater passing through the water pipes 11a to 11c can be adjusted. In the present embodiment, stainless steel pipes are used as the water supply pipes 11a to 11c.

  Since the head of the groundwater varies depending on the time and season, as shown in FIG. 3, when the head of the groundwater is the highest (the head position of A in the figure), the opening and closing valves 12b and 12c are closed and the opening and closing valve 12a is opened. Open and take groundwater using the water pipe 11a. If the open / close valve 12c is opened and water is taken from the water intake port 10c when the groundwater head is at its highest level, the groundwater momentum becomes strong and water intake becomes difficult due to the large water head difference. Water is taken from the water intake 10a. When the groundwater head is slightly low (B head position in the figure), the on-off valves 12a and 12c are closed, the on-off valve 12b is opened, and groundwater is taken in using the water supply pipe 11b. Further, when the groundwater head is the lowest (head position C in the figure), the open / close valves 12a and 12b are closed, the open / close valve 12c is opened, and the water supply pipe 11c is used to take in the groundwater.

  Since the head of groundwater varies depending on the time and season, the intake 10c is provided at a position slightly deeper than the lowest depth of the groundwater head throughout the time and season, and the intake 10a is the highest depth of the groundwater head. It is provided at a slightly deeper position. And the water intake 10b is provided in the middle of the water intake 10a and the water intake 10c.

  The opening depth of each of the intakes 10a to 10c is determined based on the result of the hydraulic survey after the hydraulic survey for investigating the groundwater pressure state.

  The water collection pipe 9 also has a function as a structural member for improving the shear strength against a shear load acting perpendicularly to the wall surface of the soil cement column wall 2 at the time of an earthquake or the like. Around the upper end of the water collecting pipe 9, a manhole 17 is constructed in the soil cement column wall 2 for use during maintenance. At the time of periodic inspection, first, the lid of the manhole 17 and the cap 18 of the water collecting pipe 9 are removed, and the inside of the water collecting pipe 9 is cleaned.

  According to the well 1 in the present embodiment described above, even if the water collecting pipe 9 having corrosion resistance and the water head of the groundwater fluctuate, at least one water intake 10a is provided to have a depth deeper than the water head. 10c and water intake pipes 11a to 11c that are connected to the water intakes 10a to 10c and feed the ground water in the water collecting pipe 9 to the water storage tank 22, so that the ground water can be collected even without power from a pump or the like. The water can be taken from inside 9 and can be supplied to the water storage tank 22 through the water supply pipes 11a to 11c. Therefore, there is no need to install equipment such as a power supply on the ground.

  Moreover, since the on-off valves 12a-12c for adjusting the amount of water passing through the water supply pipes 11a-11c are provided, the amount of water supply can be adjusted.

  Moreover, since the water pipes 11a-11c are embed | buried in the ground and the water tank 22 is installed in the underground structure 3, it is not necessary to install the water pipes 11a-11c and the water tank 22 on the ground. Therefore, the ground can be used effectively.

  Moreover, since the cap 18 for preventing the air from entering and exiting the water collection pipe 9 and the outside is provided, the groundwater does not touch the air. Therefore, iron in groundwater does not oxidize or adversely affect the ecology of microorganisms. Furthermore, if the water collection pipe 9, the water supply pipes 11a to 11c, and the cap 18 are made of stainless steel, corrosion such as rust does not occur. Therefore, the well 1 can be used for a long time.

  And in constructing the underground structure 3, the holes 8 constructed in the soil cement column wall 2 can be used as they are for the purpose of lowering the groundwater level. Thereby, there is no need to newly drill a hole for the well 1.

  In addition, in this embodiment, although the case where the well 1 was installed in the earth retaining wall which is the soil cement pillar row wall 2 was demonstrated, it is not limited to this, In the ground outside an earth retaining wall You may provide directly in.

  Moreover, in this embodiment, although the case where the water collection pipe | tube 9, the water supply pipe | tubes 11a-11c, and the cap 18 shall consist of stainless steel was demonstrated, it is not limited to this, For example, a polyvinyl chloride pipe | tube and a plastic pipe | tube are used. It may be used.

  Furthermore, in this embodiment, although the case where the well 1 was installed in the ground which consists of the ground surface layer 5, the clay layer 6, and the sand layer 7 was demonstrated, a ground layer is not limited to these, For example, FIG. As shown, the surrounding area is a ground composed of a sand layer 7 and can be applied to the case where the head of groundwater exists near the ground surface. In that case, the bottom end of the water collecting pipe 9 is provided in the soil cement column wall 2. In order to prevent the groundwater from flowing between the water collecting pipe 9 and the soil cement column wall 2, a bentonite part 14 may be provided around the part.

  In the present embodiment, the case where the hole 8 is provided as a construction well has been described. However, the present invention is not limited to this and may be provided for other purposes.

It is a perspective view which shows the state which installed the well which concerns on embodiment of this invention in the soil cement column wall. It is a longitudinal cross-sectional view which shows the state which installed the well which concerns on this embodiment in the soil cement pillar row wall. It is a figure which shows the fluctuation | variation of the head of the pressurized groundwater in the well which concerns on this embodiment. It is a figure which shows the other Example of the well which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Well 2 Soil cement column wall 3 Underground structure 4 Construction plan place 5 Ground layer 6 Clay layer 7 Sand layer 8 Hole 9 Water collecting pipe 10a, 10b, 10c Water intake port 11a, 11b, 11c Water supply pipe 12a, 12b, 12c Open / close valve 13 Filter part 14 Bentonite part 16 Screen 17 Manhole 18 Cap 19 O-ring 22 Water tank

Claims (11)

In constructing an underground structure, it is a well constructed using a hole provided for taking groundwater around the underground structure,
A pipe installed in the hole and capable of collecting groundwater inside;
A water intake provided on the side of the pipe at a depth deeper than the head of groundwater, and for taking groundwater in the pipe;
A well connected to the water intake and provided with a water supply pipe for supplying groundwater in the pipe to a predetermined place.   The well according to claim 1, further comprising a valve for adjusting the amount of water passing through the water pipe.   The well according to claim 1, further comprising a water storage tank for storing groundwater taken from the water intake.   The well according to any one of claims 1 to 3, wherein the water pipe is embedded in the ground, and the water tank is installed in an underground structure.   The well according to claim 1, wherein a plurality of the water intakes are provided at different depths along the longitudinal direction of the pipe.   The well according to claim 1, wherein the tube includes a lid at an upper end.   The well according to claim 1, wherein the pipe, the water supply pipe, and the lid are made of a corrosion-resistant material.   The well according to claim 1, wherein the hole is provided in the underground structure.   The well according to any one of claims 1 to 8, wherein one end of the water pipe is installed so as to protrude from the underground structure.   The said hole is provided in the circumference | surroundings of the construction planned location of the said underground structure, and is provided in the earth retaining wall for preventing inflow of the groundwater and earth and sand to the said construction planned location. Well described in. In constructing an underground structure, in a method for constructing a well constructed using holes provided for taking groundwater around the underground structure,
A pipe installation step of installing a pipe capable of collecting groundwater in the hole;
An opening step of providing a water intake for taking groundwater in the pipe on the side surface of the pipe at a depth deeper than the head of groundwater;
And a connecting step of connecting a water supply pipe for supplying the groundwater in the pipe to a predetermined place to the water intake.

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