KR20110012704A - Ground construction method using displacement-control pile - Google Patents

Abstract

PURPOSE: A construction method of an underground wall using a displacement control pile is provided to efficiently drain water on the rear surface of an underground wall and to control construction errors. CONSTITUTION: A construction method of an underground wall using a displacement control pile is as follows. Displacement control piles(100), in which displacement control tendons(110) are previously set on the rear surfaces, are manufactured. An underground wall is formed by consecutively installing the displacement control piles in the ground. Pre-stress is applied to the underground wall in an opposite direction of displacement by tensing and anchoring the displacement control tendons. The ground of the front part of the underground wall is excavated.

Description

Ground wall construction method using displacement control pile {GROUND CONSTRUCTION METHOD USING DISPLACEMENT-CONTROL PILE}

The present invention relates to a construction method for underground wall using a displacement control pile. More specifically, it is possible to construct underground walls by continuously installing piles such as reinforced concrete piles in the ground, and to control the displacement of underground walls that may occur after the construction process and completion, and to efficiently drain the flow of the back surface of the underground walls. The present invention relates to an underground wall construction method using a displacement control pile to prevent an increase in side pressure due to water pressure caused by groundwater.

In general, the reason for constructing a continuous wall such as an incision can be said to stably construct a structure such as a road in the longitudinal direction on the wall front face.

In other words, when the road is constructed by cutting off the foot of a mountain, the cut-out part may collapse so that the collapse can be prevented by using a wall.

Accordingly, the wall is constructed in a continuous manner in the longitudinal direction of a structure such as a road, and such a wall may be constructed in various ways such as a retaining wall structure.

Such wall construction is usually constructed with reinforced concrete structures, and in the case of installing concrete and installing concrete on the site in order to construct a wall structure having a certain thickness, the work is cumbersome in the field and various forms of precast structures How to construct a wall is introduced.

FIG. 1A illustrates an example in which the wall is constructed using a PHC file (high strength hollow file by pretension), and the PC file 10 is continuously installed in a constant direction on the ground. This is because individual PC files must be installed adjacent to each other to have a wall shape.

In general, a wall is constructed by forming a drilling hole in the ground and inserting a PC file into the drilling hole. Thus, the wall is also referred to as the underground wall in the sense of constructing the wall by inserting the file continuously into the ground.

At this time, in order to structurally integrate the PC files adjacent to each other, a connecting table 20 or a projection 30 may be installed at the connecting contact portion of the PC file, so that the wall by the PC file is structurally integrated.

In this way, the wall is continuously formed by the PC pile in the ground, and the front part of the wall by the PC pile is excavated to install a predetermined structure (road, etc.) in the excavated space.

FIG. 1B illustrates an example of using a composite file 50 formed inside a steel frame, not a PC file, as a file for underground walls. Even when using the composite file, the process of constructing the underground wall is not significantly different from that of a PC file. not.

The problem that occurs when using a PC file or a composite file as described above is that it is not easy to allow the files to be installed straight in the vertical direction.

This problem

First, it may be due to construction errors. In other words, when the pile is installed on the ground, the pile is inclined because it cannot be installed vertically for a variety of reasons.

Second, even if the pile is properly constructed, the ground wall can be inclined due to the excavation of the front part of the underground wall and the load caused by the earth pressure and water pressure acting on the rear part.

Even if the underground wall is not constructed vertically, it may not be a structural problem, but since it may cause anxiety in appearance, it must be managed when the underground wall is tilted.

However, if such problems are found after the construction of the underground wall, there is a problem that it is almost impossible to control them.

Accordingly, the present invention is to provide a construction method for underground wall construction using a displacement control file that can be controlled so that the construction of the vertical wall even after the construction process and construction in the construction of the underground wall using the pile as a technical problem to solve the problem. do.

The present invention to achieve the above technical problem

First, when the pile installed on the ground is inclined for a variety of reasons and a displacement occurs in a specific direction, the prestress by the tension member is introduced in the opposite direction in which the displacement occurs to cancel the displacement.

In other words, the tension member is disposed on the pile in advance so as to cancel the displacement of the pile formed by being inclined straight due to the prestress.

At this time, since the displacement of the pile usually occurs from the rear portion of the pile to the front portion, the tension member is installed in advance on one side of the rear portion of the pile.

Even after the piles are continuously constructed, the pile may further cause displacement.

Therefore, the tension member is installed at least two or more, so that some of the tension can be tensioned when necessary to offset the displacement occurring in the underground wall.

Second, since the underground wall is to be installed in the ground, it is prepared to receive water pressure by groundwater contained in the ground. Since such water pressure also causes displacement in the underground wall, it is necessary to prevent the underground wall from being affected by the water pressure as much as possible.

To this end, in particular, the present invention extends to the side portion from the back portion of the pile to form a drainage groove or a drain board directly in the pile rear portion to induce groundwater or the like so as to drain inflow water through the drainage groove.

When the underground wall is constructed by continuously installing the pile according to the present invention, it is possible to control the construction error caused by not being vertically constructed, which makes it very efficient in the construction and quality control of the underground wall.

In addition, it is possible to control the displacement irrespective of the cause of the displacement of the underground wall, and it is very economical to control the displacement because it uses a PC tension member and a hydraulic jack which are commonly used without any other special equipment.

In addition, since the pile itself can be used for drainage of the underground wall, the use of the underground wall by the drainage treatment is also very efficient.

The scope of the present invention is shown by the following claims rather than the above description, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention. do.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Each step of the construction method of the underground wall construction method using the displacement control pile according to the present invention will be described with reference to Figures 5a to 5h, with reference to Figures 2, 3a to 3e in detail.

First, to prepare a displacement control pile 100 for constructing the underground wall (A) according to the present invention.

The displacement control file 100 may be a PC file as described above, or a synthetic file may be used.

The reinforced concrete pile (pile) may have a variety of cross-sectional shapes, such as round, square, it is desirable to be formed in a cross-sectional shape having a large cross-sectional area, such as oval in consideration of the ground wall.

First, as shown in Figure 2 to produce a reinforced concrete pile as a displacement control file 100, the tension member 110 in the longitudinal direction is further disposed inside the reinforced concrete file.

The tension member 110 is to be additionally placed separately from the PC steel or reinforcing bars originally placed in the reinforced concrete pile, steel bar or PC steel wire may be used.

The lower end of the tension member 110 (the lower inside of the reinforced concrete pile) is fixed by the fixture 130, and the upper end is disposed to extend out from the upper surface of the reinforced concrete pile.

Of course, the tension member 110 is to be pre-formed in the upper portion of the reinforced concrete pile in advance for tension and fixation of the tension member 110, so that the tension member 110 can be tensioned and fixed at any time.

At this time, the steel bar or PC steel wire is set in advance in the reinforced concrete pile sheath pipe 140, so that the tension material by the steel bar or PC steel wire is placed in the sheath pipe 140.

What is important at this time is the arrangement position of the tension member 110.

In other words, the reinforced concrete pile is installed in the ground and its front part is excavated to a certain depth. This is to secure the space for the construction of structures such as roads as described above.

Therefore, when the front part is excavated, the ground supporting the front part of the reinforced concrete pile is excluded, so that earth pressure is generated from the rear part of the reinforced concrete pile to the front part, which causes the reinforced concrete pile to be inclined to the front part. .

Such a displacement causes the reinforced concrete pile to be inclined, so that the underground wall, in which the reinforced concrete pile is continuously formed and constructed, is also inclined.

In order to prevent this, the position of the tension member 110 is set so that displacement occurs in a direction opposite to the displacement direction occurring in the reinforced concrete pile.

That is, the tension member 110 is located on the rear side of the reinforced concrete pile to tension and fix the upper end of the tension member so that the pre-stress in the vertical direction is introduced to the rear side to control the horizontal displacement occurring in the reinforced concrete pile. It would be.

In this case, the displacement occurring in the reinforced concrete pile may occur during the construction process or may occur after the construction.

Therefore, the tension member 110 is to be placed in the sheath tube, when the displacement occurs, the tension member 110 is to be tensioned and settled. In addition, the tension member 110 is installed in a number of reinforced concrete piles so as to change the time and the amount of time required by each of the reinforcement concrete pile, it is possible to efficiently respond to a lot of site conditions change.

In addition, the drain groove 150 is further formed on the rear surface of the reinforced concrete pile. The drain groove 150 is generated in the back portion of the reinforced concrete piles constructed on the ground, as well as the water pressure due to the groundwater and ground pressure.

The hydraulic pressure may also cause the reinforced concrete pile to be inclined, and because of this, side pressure may occur in the reinforced concrete pile, so that groundwater, which is a cause of the hydraulic pressure, is drained to the front portion of the reinforced concrete pile in order to control the hydraulic pressure. It is to let.

The drainage groove 150 is formed in the back portion of the reinforced concrete pile in the form of a groove as its name to extend to the side portion of the reinforced concrete pile, and eventually, the groundwater or the like by the drainage groove 150 Induce drainage to the front of the pile.

Since the drain groove 150 is formed in the form of a groove dug in the surface of the reinforced concrete pile, it may be blocked by earth and sand. Thus, the drain groove 150 is preferably to be covered with a nonwoven fabric.

In addition, instead of the drain groove 150, a drain board may be installed on the rear portion of the reinforced concrete pile.

The drain board is an induction drainage means usually installed at the rear part of the underground wall, and the drain board is attached to the reinforced concrete pile, and the drainage grooves formed with the groundwater induced by the drain board are also formed on the side of the reinforced concrete pile ( 150) to be guided to the front portion of the reinforced concrete pile.

When the displacement control file 100 according to the present invention is prepared, such a displacement control file 100 is installed on the ground 200 to construct the ground wall A, which is based on FIGS. 5 and 3A to 3D. Take a look.

First, as shown in FIGS. 3A, 5A, and 5B, the perforation holes 210 are installed in a line at positions where the underground wall A is to be constructed.

The drilling hole 210 is to be constructed at a constant depth (H), if based on Figure 3a, it is installed by inserting the displacement control file 100.

Since the displacement control file 100 is installed to expose the upper end of the tension member 110, it cannot be used otherwise by the method of driving, so that the construction is inserted into the drilling hole 210.

In addition, the drilling hole 210 may be inserted into the drilling hole 210 in accordance with the state of the ground to prevent the collapse of the drilling hole.

In addition, the front portion of the displacement control pile 100 is excavated to a predetermined depth (H2), such a depth is set in advance to the planned drilling line (L), after the excavation of the front ground ground, the open space of the front portion of the reinforced concrete pile It will be used as a space for constructing structures.

Next, as shown in FIGS. 3B and 5C, the grouting material 300 is hardened over time, such as mortar and cement paste, from the bottom of the displacement control pile 100 to the planned excavation line L.

The reason for filling the grouting material 300 is to ensure that the displacement control pile 100 is integrated with the ground 200 and fixed up to the height H1 of the grouting material 300 is cured.

Thus, it can be seen that the displacement control pile 100 fixed to the ground up to a certain height (H1) can act as a cantilever beam structure having a fixed bottom, and later the displacement control pile 100 up to the planned drilling line (L). When the part is excavated, the displacement by the earth pressure, etc. acting on the displacement control pile 100 can be resisted as the cantilever beam structure.

At this time, the casing installed before the grouting material 300 is cured is removed.

As such, the filling of the displacement control pile 100 and the grouting material 300 is repeated to construct the underground wall A extending in the longitudinal direction as shown in FIGS. 4 and 5D.

At this time, the height control operation of the grouting material 300 presents two methods in the present invention.

First, when the displacement control pile 100 is manufactured, a central pipe extending in advance to the planned drilling line L and a branch pipe connected to the outside of the displacement control pile 100 from the lower portion of the central pipe in advance are provided.

At this time, the branch pipe is to be exposed slightly above the planned drilling line (L).

This is the case of controlling the height of the grouting material 300 to the planned drilling line (L) by allowing the grouting material injected in the upper part of the planned drilling line through the branch pipe to be introduced into the central pipe and then pumped it out.

In other words, as shown in FIG. 6a, since the operation of precisely filling the mortar and grouting material 300 from the bottom surface of the displacement control pile 100 to the planned excavation line L is not easy in the field, the grouting material 300 is drilled into the hole ( The space between the 210 and the displacement control pile 100 is filled in the entire depth H of the drilling hole 210.

The suction pipe is installed on the upper end of the center pipe so that the grouting material 300 is forced to suck the branch pipe connected to the center pipe of the displacement control pile 100, and is filled in the upper part of the planned drilling line (L) by the suction pump. The grouting material 300 is to be discharged.

Second, the grouting material by inserting a pumping hose directly into the pile front part and the rear part in the space between the drilling hole 210 and the displacement control pile 100 to the planned excavation line by pumping out the grouting material injected into the upper part of the planned excavation line. This is a method of controlling the height of 300.

In this method, the grouting material 300 is sufficiently filled in the space between the drilling hole 210 and the displacement control pile 100, and the grouting material 300 is formed only up to the planned excavation line L as shown in FIG. 6B. It is to be discharged from the hole again through the suction pump as much as possible.

This may be selected in consideration of the manufacturing conditions and site conditions for the displacement control file 100, and eventually the grouting material is filled up to the planned excavation line (L) so that the displacement control file 100 fixed to the ground to a certain height (H1) is The key is to allow the bottom to act as a fixed cantilever beam structure.

When the underground wall (A) is constructed as described above, the tension member 110 disposed on the displacement control pile 100 is tensioned and fixed as shown in FIGS. 3C and 5E. In this case, the lower portion of the displacement control pile 100 is a grouting material ( Since it is fixed by 300, the prestress due to tension and fixation of the tension member 110 generates a displacement only with respect to the height (H2) from the planned drilling line (L) to the top of the displacement control pile (100).

Such a displacement causes a displacement of the displacement control pile 100 to the right based on FIG. 3C, which means that the horizontal ground reaction coefficient K2 corresponding to the height H1 corresponds to the horizontal square ground coefficient corresponding to the height H2 ( Since it is larger than K1), the displacement adjusting file 100 corresponding to the height of H2 has a mechanism in which displacement occurs to the right.

Therefore, if there is no lower fixing process of the displacement control pile 100 by the grouting material 300, an unspecified displacement may occur over the entire displacement control pile 100 by prestress by the tension member 110, so that the tension member 110 By the prestress by the horizontal displacement of the displacement control file 100 to be guided in the desired direction.

This induced displacement is in the opposite direction to the displacement of the underground wall caused by the ground excavation of the ground wall (A) in the future to eventually manage the inclination of the ground wall.

Next, as shown in FIGS. 3D and 5F, the front portion of the displacement control pile 100 is excavated to the planned excavation line L.

When the excavation is completed, the excavated front ground is excluded, so that the earth pressure of the rear surface of the displacement control pile 100 corresponding to the height H2 acts on the displacement control pile 100 without resistance.

Accordingly, it can be seen that the displacement control pile 100 is offset by the tension material by the earth pressure, and thus the degree of inclination of the underground wall A can be managed.

At this time, the displacement of the displacement control file 100 by the tension control and the front part excavation may be different from each other, the fine displacement as shown in Figure 5g using the tension, the tension member is not fixed in the tension member 110 It is desirable to be able to adjust the difference.

The tension member 110 can be seen that the tension and settling in the construction process by varying the timing and amount.

4 and 5h, the underground wall A constructed as shown in FIG. 4 and 5h can be seen to be installed straight in the vertical direction without inclination, and further formed a kaepbim 400 in the longitudinal direction at the top to complete the shape of the underground wall In addition to this, the integrity of the underground walls is enhanced and completed.

Accordingly, when the underground wall (A) is finally completed, the required structures such as roads are constructed in the space excavated to the planned excavation line (L).

1A and 1B are a plan view and a perspective view showing an example of a pile used in a conventional underground wall,

Figure 2 is a perspective view showing an example of the displacement control file used in the present invention,

3a, 3b, 3c and 3d is a flow chart for constructing the underground wall using the displacement control pile of the present invention,

Figure 4 is a perspective view showing an example of the underground wall using the displacement control file of the present invention.

Figure 5 shows the construction sequence of the underground wall using the displacement control file of the present invention in detail.

6A and 6B illustrate an example of a method of controlling the height of the grouting material between the displacement adjusting pile and the drilling hole of the present invention.

<Brief description of the major reference numerals>

100: displacement control pile 110: tension material

120: fixing unit 130: fixing unit

140: sheath pipe 150: drain groove

200: ground 300: grouting material

400: kabbeam

Claims (9)

In the method of constructing the underground wall by continuously installing piles in the ground, Manufacturing a displacement control file 100 having a displacement control tension member 110 set in a vertical direction in advance on the back side, and continuously installing the displacement control file on the ground to form an underground wall; Introducing a prestress in a direction opposite to a displacement generated due to earth pressure acting on the ground wall by tensioning and fixing the displacement adjusting tension member pre-installed in the displacement adjusting pile; And Underground construction method using a displacement control pile including the step of excavating the front ground of the underground wall to the excavation plan (L). The method of claim 1, wherein in the forming of the underground wall, the displacement control pile is formed to form a drilling hole into which the displacement control pile can be inserted into the ground, and then repeats the operation of allowing the displacement control pile to be inserted into the drilling hole. Construction method of underground wall using the displacement control pile so that the underground wall is formed by continuously installing the displacement control pile. According to claim 1, wherein the rear portion of the displacement control pile to further form a drain groove extending to the front surface of the underground wall through the side portion to guide the inflow of water from the back of the underground wall to the underground wall front portion, the non-woven fabric in the drain groove Construction method of underground wall using the displacement control pile to prevent the foreign matter from entering the drain groove by installing more. The method of claim 1, wherein the rear surface of the displacement control pile is further provided with a drain board to guide the inflow of water from the rear surface of the ground wall to the front surface of the ground wall by the drain board. The method of claim 1, wherein the displacement control pile is a ground wall construction method using a displacement control pile such that reinforced concrete piles are used. According to claim 2, After the grouting material is injected between the displacement control file and the drilling hole, the lower end of the displacement control file to be fixed to the height of the grouting material injection, so that the bottom of the underground wall is fixed in the prestress Construction method for underground walls using displacement control piles. [7] The prestress of claim 6, wherein the prestress is formed by providing an extra tension in the tension member so as to compensate for the displacement of the additional ground wall caused by excavating the front ground of the ground wall into which the prestress is introduced. Construction method for underground walls using displacement control piles to introduce prestress. The pipe of claim 6, wherein a center pipe is further formed inside the displacement control pile, and a pipe branched from the center pipe to the outside of the displacement control pile is formed to separate the grouting material injected above the planned drilling line. Method for construction of underground walls using displacement control piles to control the height of the grouting material by allowing it to flow into the central pipe and then pumping it out. The ground using a displacement control pile to control the height of the grouting material by controlling the height of the grouting material by inserting the pumping hose directly to the planned excavation line by pumping the grouting material injected into the upper part of the planned excavation line. Wall construction method.

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