JP4905296B2 - Method for constructing retaining wall and retaining wall - Google Patents

Description

  The present invention relates to a mountain retaining wall that can prevent the flow of groundwater from being blocked in the ground.

  When constructing an underground structure by the open-cut method or the like, a water-impervious earth retaining wall is formed in the ground to prevent entry of groundwater into the work area. However, by forming a retaining wall, the flow of groundwater in the ground is obstructed, so that groundwater does not flow downstream of the retaining wall, and the water level of the well on the downstream side decreases, or ground subsidence occurs. There was a problem. Therefore, an opening is provided in a portion of the earth retaining wall located in the aquifer to allow groundwater to flow downstream.

  For example, Patent Document 1 forms a retaining wall composed of a water stop wall up to a predetermined depth deeper than the aquifer and a wall up to a depth shallower than the aquifer, and includes the aquifer. A method is disclosed in which when the ground is frozen to block the flow of groundwater and the underground structure is constructed, the frozen ground is thawed and the groundwater is passed downstream.

Further, in Patent Document 2, a vertical working hole is formed at a desired interval on the earth retaining wall made of soil cement at the time of or after the construction, and an impact transmission material such as water is formed in the work hole. A probe for supplying electric power for plasma generation is inserted, and electric power is supplied to generate a shock wave by the plasma to crush the impermeable earth retaining wall. Through the gap generated by this crushing, groundwater A method of passing water downstream is disclosed.
JP 2000-136528 A JP 2004-124575 A

  However, the method described in Patent Document 1 has a problem in that since a wide range of ground including the aquifer is frozen, it may adversely affect living creatures and plants that inhabit the ground. Furthermore, since a wide range has to be frozen over a long period of time, there is a problem in that capital investment and maintenance costs are incurred and construction costs are high.

  Further, the method described in Patent Document 2 has a problem that the equipment investment cost is high because the apparatus for generating plasma power is expensive. In addition, there is a problem that electric leakage may occur in the vicinity when it rains.

  Therefore, the present invention has been made in view of the conventional problems as described above, and has an object to provide a retaining wall and a construction method thereof that can be safely constructed at a low cost with little influence on the environment. And

In order to achieve the above object, a method for constructing a retaining wall according to the present invention is a method for constructing a retaining wall that prevents the flow of groundwater from being hindered, and has a joint in the ground at a predetermined location of the planned construction position of the retaining wall. The first installation step of placing the first water-stopping steel material, and the planned construction position excluding the place where the first water-stopping steel material is placed, hardens over time, and the mountain retaining wall The hardened material to be configured is in a fluidized state, and a placing step for placing the joint of the first water-stopping steel material so as not to enter the mountain retaining wall ; and a second water-stopping steel material having a joint, A second installation step of placing in the hardened material in a fluidized state so as to engage with a joint of the first water-stopping steel material outside the mountain retaining wall; and the first water-stopping steel material. And a pulling-up process for raising the groundwater to a predetermined depth that allows water to flow. To (first invention).

According to the method for constructing a retaining wall according to the present invention, since the first water-stopping steel material is pulled up to a predetermined depth shallower than the depth where the aquifer exists, the groundwater passes through the aquifer after the construction is completed. It becomes possible, and the groundwater upstream of the retaining wall can be passed downstream.
Moreover, since the 1st water stop steel material is installed in the ground and is not installed in the inside of the earth retaining wall, it can be pulled up easily.

  Furthermore, since the first and second installation steps and the lifting step can be performed by using a machine such as a placement machine or a crane used when constructing a general retaining wall, a new capital investment cost is newly provided. It does not take. Moreover, since these operations can be carried out in a short time without trouble, they can be constructed in a shorter period of time than a conventional retaining wall capable of preventing flow hindrance. Therefore, the construction period is shortened and the construction cost can be reduced.

According to a second aspect of the present invention, in the first aspect of the present invention, the method further comprises a water stop step of providing a water stop material having a water shielding property to the engaged joint.
According to the method for constructing a retaining wall according to the present invention, a water-stopping material having a water blocking property is provided in a joint in which a joint of a first water-stopping steel material and a joint of a second water-stopping steel material are engaged. Can be impermeable.

A third invention is characterized in that, in the second invention, the waterstop material maintains a deformable property without solidifying.
According to the method for constructing the retaining wall according to the present invention, the water stop material maintains a deformable property without solidifying, so even if the water stop steel material is moved in the vertical direction or the horizontal direction, The joint can be deformed following the shape of the joint of the water steel material, and the joint can be reliably insulated.

  Moreover, since the water stop material is freely deformable, it can be easily pulled up without causing resistance even when the first water stop steel material is pulled up. Therefore, when pulling up the first water-stopping steel material, the second water-stopping steel material is not subjected to an impact such as vibration or collision, so that the earth retaining wall in which the second water-stopping steel material is embedded is damaged. There is no.

A mountain retaining wall according to a fourth aspect of the present invention is a mountain retaining wall that prevents the flow of groundwater from being hindered. The wall is constructed by placing a hardening material that hardens over time into the ground at a predetermined interval, and a joint. A first water-stopping steel material installed so that the joint does not enter the wall portion at a depth shallower than a predetermined aquifer in the ground between the adjacent wall portions, and a joint And the joint is engaged with the joint of the first water-stopping steel material on the outside of the wall portion, and includes a second water-stopping steel material installed in the wall portion. To do.

  The fifth invention is characterized in that, in the fourth invention, the engaging joint is provided with a water-stopping material having a water shielding property while maintaining a deformable property without solidifying. .

  By using the mountain retaining wall construction method of the present invention, it is possible to construct a retaining wall that has little influence on the environment and that can prevent the flow of groundwater from being hindered at low cost.

  Hereinafter, a preferred embodiment of a method for constructing a retaining wall according to the present invention will be described in detail with reference to the drawings. In addition, although the following embodiment demonstrates the case where the soil cement pillar row wall which is a retaining wall is installed in a natural mountain, this invention is applicable also to retaining walls, such as RC.

  1 and 2 are a perspective sectional view and a longitudinal sectional view, respectively, showing a soil cement column wall 1 according to an embodiment of the present invention.

  As shown in FIGS. 1 and 2, the soil cement column wall 1 includes a soil cement column 1A constructed by placing a hardened material that hardens with time in the ground at a predetermined interval, and a joint. A first water-stopping steel material 9 installed on the clay layer 3 of the water-impervious layer at a depth shallower than the sand layer 4 of the aquifer in the ground between the adjacent soil cement column arrays 1A, and a joint And is engaged with a joint of the first water-stopping steel material 9 and includes second water-stopping steel materials 7a and 7b installed in the soil cement column array 1A.

  The soil cement column 1A is constructed so as to penetrate the clay layer 3 and the sand layer 4 and reach the upper part of the Dotan layer 5 which is a water-impervious layer.

  The second water-stopping steel materials 7a and 7b are installed so as to have substantially the same depth as that of the soil cement column 1A.

  Since the first water-stopping steel material 9 is installed in the clay layer 3 having a shallower depth than the sand layer 4, the groundwater upstream of the soil cement column wall 1 is the sand layer 4 between the soil cement column columns 1A. Can flow downstream.

  In the joint portion 10 where the joints of the second water-stopping steel materials 7a and 7b and the joints of the first water-stopping steel material 9 are engaged, the ground water passes through the joint portion 10 and the soil cement column wall. 1 is filled with a water blocking material 12 so as not to flow into the planned excavation site 6.

  In the present embodiment, sheet piles having joints at both ends are used as the first water-stopping steel material 9 and the second water-stopping steel materials 7a and 7b. However, the present invention is not limited to this. A steel sheet pile or the like may be used.

  In addition, when constructing the underground structure 2 on the inner side surrounded by the soil cement column wall 1, the first water-stopping steel material 9 includes the clay layer 3 and the It is installed so as to penetrate the sand layer 4 and reach the Dotan layer 5, and after constructing the underground structure 2, it is pulled up to the clay layer 3 in order to pass the ground water of the sand layer 4 (details) Will be described later). The installation position and the like of the first water-stopping steel material 9 are determined by design and differ depending on each site.

Next, the construction method of the soil cement column wall 1 described above will be described.
3-9 is a figure which shows the construction procedure of the soil cement column wall 1 which concerns on this embodiment.

First, as shown in FIG. 3, a first water-stopping steel material 9 is placed at a predetermined location of a planned construction position 18 of the soil cement column wall 1 with a placement machine 8 installed on the ground.
The first water-stopping steel material 9 is placed until the lower end of the water-stopping steel material reaches the Dotan layer 5.

Next, as shown in FIG. 4, columnar holes are drilled at the planned construction positions 18 on both sides of the first water-stopping steel material 9, and the holes are filled with cement milk. A soil cement column 1A with the soil as an aggregate is constructed.
The soil cement column 1A is constructed so as to penetrate the clay layer 3 and the sand layer 4 and reach the upper part of the Dotan layer 5.

  Next, as shown in FIG. 5A and FIG. 5B, the soil cement in a fluidized state so that the second water-stopping steel material 7 a is engaged with the joint of the first water-stopping steel material 9 by the driving machine 8. Place in. The second water-stopping steel material 7a is formed by engaging one joint of the first water-stopping steel material 9 and the joint of the second water-stopping steel material 7a while the second water-stopping steel material 7a is engaged. The process is performed until the lower end of 7a reaches almost the same depth as the lower end of the soil cement column 1A.

  Moreover, the 2nd water stop steel material 7b is installed similarly to the 2nd water stop steel material 7a mentioned above. The second water-stopping steel material 7b is also engaged with the other joint of the first water-stopping steel material 9 and the joint of the second water-stopping steel material 7b, and the lower end of the second water-stopping steel material 7b. Is driven until it reaches substantially the same depth as the lower end of the soil cement column 1A.

  Next, as shown in FIGS. 6A and 6B, the H-shaped steel 11 is built in the soil cement column 1b adjacent to the soil cement column 1a in which the second water-stopping steel materials 7a and 7b are placed. The H-shaped steel 11 is built until the lower end of the H-shaped steel 11 reaches substantially the same depth as the lower end of the soil cement column wall 1.

  Next, the water stop material 12 is filled in the joint portion 10. Although not shown, an injection pipe for injecting the water-stopping material 12 is inserted to the bottom of the hole in the joint portion 10, and the water-stopping material 12 is filled into the joint portion 10 from the tip of the pipe while gradually raising the injection pipe. The water blocking material 12 is filled in the joint portion 10 and pressed against and closely contacts the inner peripheral surfaces of both the joints to exhibit water blocking properties.

  In this embodiment, after the first water-stopping steel material 9 and the second water-stopping steel materials 7a and 7b are placed, the water-stopping material is filled into the joint portion 10 to stop the joint portion 10. Although the method for watering has been described, the present invention is not limited to this. For example, before placing the second water-stopping steel materials 7a and 7b, a water-swellable water-insulating material is applied to the joints in advance. After the second water-stopping steel materials 7a and 7b are driven so as to be engaged with the joint of the first water-stopping steel material 9 that has already been driven in the ground, the water swelling property A method may be used in which the water shielding material swells by absorbing moisture in the ground, and stops water by contacting the inner peripheral surface or the outer peripheral surface of the joint of the first water-stopping steel material 9.

The water blocking material 12 is formed by mixing sand, water, and highly swellable bentonite, and has an appropriate viscosity and a large specific gravity (1.8 to 2.0 t / m ³ ). Is also excellent and has good workability. Further, since the water-stopping material 12 contains sand, the volume is hardly reduced even when consolidated, and the sand particles are rubbed with each other through the swollen particles of highly swellable bentonite, so that the deformation followability is improved. Since it has, even if it pulls up the 1st steel material 9 for water stop, the joint part 10 (after-mentioned) maintains water stop performance.

  Next, as shown in FIG. 7, after the soil cement column wall 1 </ b> A is hardened, the water supply means 14 for passing the groundwater under construction of the underground structure 2 downstream is provided with the soil cement column wall 1. The groundwater on the upstream side is passed downstream.

  The water supply means 14 includes a pumping well 15 for pumping up the groundwater on the upstream side, a condensate well 16 for returning the groundwater pumped from the pumping well 15 to the downstream side, and a groundwater pumped from the pumping well 15 to the condensate well 16. It consists of a water pipe 17 for feeding.

Although not shown, the pumping well 15 includes a pumping pump, a pumping flow meter for measuring the discharge amount discharged from the pumping pump, and a water level meter for measuring the groundwater level.
Although not shown, the condensate well 16 includes a condensate flow meter for measuring the amount of condensate to be condensed and a water level meter for measuring the groundwater level.
The water supply pipe 17 connects the pumping well 15 and the condensate well 16 and supplies the groundwater pumped from the pumping well 15 to the condensate well 16 without exposing it to the atmosphere. Groundwater pumped from a certain pumping well 15 is connected to all the condensate wells 16 via a water pipe 17 so that the water can be condensed.

  Next, as shown in FIG. 8, the excavation planned location 6 surrounded by the soil cement column wall 1 is excavated to form a cavity, and the underground structure 2 is constructed in this cavity.

  Finally, as shown in FIG. 9, the first water-stopping steel material 9 is pulled up by the crane 19 until the lower end of the first water-stopping steel material 9 reaches the clay layer 3, and the inside of the upstream sand layer 4 Of groundwater can be circulated downstream. Then, the pumping from the pumping well 15 is stopped, the groundwater level of the pumping well 15 and the groundwater level of the condensate well 16 are compared, and all the groundwater on the upstream side of the soil cement column wall 1 flows downstream. The water passing means 14 is removed.

  According to the construction method of the mountain retaining wall in the present embodiment described above, the first water-stopping steel material 9 is pulled up to the clay layer 3, so that the groundwater on the upstream side of the soil cement column wall 1 is downstream after the construction. Water can be passed to the side.

  Moreover, since the first water-stopping steel material 9 is installed in the ground and is not installed in the soil cement column array 1A, it can be easily pulled up.

  Furthermore, the work for placing the first and second water-stopping steel materials 9, 7a, 7b and the work for pulling up the first water-stopping steel material 9 are performed when constructing a general retaining wall. Since it can be carried out using heavy machinery such as the machine 8 and the crane 19, no new capital investment cost is required. Moreover, since these operations can be carried out in a short time without trouble, they can be constructed in a shorter period of time than a conventional retaining wall capable of preventing flow hindrance. Therefore, the construction period is shortened and the construction cost can be reduced.

  And since the water stop material 12 with which the joint part 10 is filled maintains the property which can deform | transform freely without solidifying, even if it pulls up the 1st steel material 9 for water stop, The joint portion 10 can be deformed following the shape of the joint portion 10 of the first water-stopping steel material 9, and the joint portion 10 can be reliably insulated.

  Moreover, since the water stop material 12 is freely deformable, it can be easily pulled up without causing resistance even when the first water stop steel material 9 is pulled up. Accordingly, when the first water-stopping steel material 9 is pulled up, the second water-stopping steel materials 7a and 7b are not subjected to impacts such as vibration and collision, so that the second water-stopping steel materials 7a and 7b are embedded. The soil cement column 1A is not damaged.

  Furthermore, even if the underground structure 2 is constructed so as to be close to the soil cement column wall 1, the first water-stopping steel material 9 can be pulled up without damaging the underground structure 2.

  In addition, in this embodiment, although the case where this invention was applied to the ground which consists of the clay layer 3, the sand layer 4, and the Dotan layer 5 was demonstrated, it is not limited to this ground layer, For example, all are the sand layers 4 That is, the ground which consists of an aquifer may be sufficient.

  Moreover, in this embodiment, although the case where only one 1st water-stopping steel material 9 was used was demonstrated, it is not limited to this, A plurality may be connected and adjacent soil cement It changes suitably according to the amount of groundwater flow etc. which pass between 1 A of column row parts.

  Furthermore, in this embodiment, although the case where the shape of the joint of the 1st water-stopping steel material 9 and the 2nd water-stopping steel materials 7a and 7b was a substantially C-shaped tubular shape was demonstrated, it is limited to this shape. For example, a plate shape such as a U-shape or a T-shape may be used, and a general joint shape can be used.

It is a perspective view which shows the soil cement pillar row wall which concerns on embodiment of this invention. It is a longitudinal cross-sectional view which shows the soil cement pillar row wall which concerns on this embodiment. It is a figure which shows the construction procedure of the soil cement pillar row wall which concerns on this embodiment. It is a figure which shows the construction procedure of the soil cement pillar row wall which concerns on this embodiment. It is a figure which shows the construction procedure of the soil cement pillar row wall which concerns on this embodiment. It is a figure which shows the construction procedure of the soil cement pillar row wall which concerns on this embodiment. It is a figure which shows the construction procedure of the soil cement pillar row wall which concerns on this embodiment. It is a figure which shows the construction procedure of the soil cement pillar row wall which concerns on this embodiment. It is a figure which shows the construction procedure of the soil cement pillar row wall which concerns on this embodiment. It is a figure which shows the construction procedure of the soil cement pillar row wall which concerns on this embodiment. It is a figure which shows the construction procedure of the soil cement pillar row wall which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Soil cement pillar row wall 1A Soil cement pillar row | line | column part 1a, 1b Soil cement pillar 2 Underground structure 3 Clay layer 4 Sand layer 5 Dotan layer 6 Drilling planned part 7a, 7b 2nd steel material 8 for water stop 8 First water-stopping steel material 10 Joint portion 11 H-shaped steel 12 Water-stopping material 14 Water supply means 15 Pumping well 16 Condensate well 17 Water supply pipe 18 Construction planned position 19 Crane

Claims (5)

In the method of constructing the retaining wall to prevent the flow of groundwater,
A first installation step of placing a first water-stopping steel material having a joint in the ground of a predetermined location of the planned construction position of the retaining wall;
The hardened material that hardens over time and forms the mountain retaining wall at the planned construction position excluding the place where the first water-stopping steel material is placed, in a fluidized state , the first water-stopping steel material. A placing step for placing a joint so as not to enter the retaining wall ;
Secondly, a second water-stopping steel material having a joint is placed in the hardened material in a fluid state so that the joint engages with the joint of the first water-stopping steel material outside the retaining wall . The installation process of
A method for constructing a retaining wall, comprising: a pulling-up step of pulling up the first water-stopping steel material to a predetermined depth through which groundwater can flow.   The method for constructing a mountain retaining wall according to claim 1, further comprising a water stopping step of providing a water blocking material having water shielding properties to the engaged joint.   The method for constructing a retaining wall according to claim 2, wherein the water blocking material maintains a deformable property without solidifying. A retaining wall to prevent the flow of groundwater,
A wall portion constructed by placing a hardening material that hardens over time into the ground at a predetermined interval;
A first water-stopping steel material that has a joint and is installed so that the joint does not enter the wall part at a depth shallower than a predetermined aquifer in the ground between the adjacent wall parts;
Having a joint, the joint being engaged with the joint of the first water-stopping steel material on the outside of the wall portion, and comprising a second water-stopping steel material installed in the wall portion. Characteristic mountain retaining wall.   5. The mountain retaining wall according to claim 4, wherein the engaged joint maintains a deformable property without solidifying and is provided with a water blocking material having a water blocking property.

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