JP5261837B2 - Placing a wooden pile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wooden pile driving method capable of preventing a wooden pile from being decayed and maintaining a state in which, by driving the wooden pile, the ground is denser, a horizontal earth pressure is increased to increase a binding force, drainability is increased and shear resistance of the entire of the ground is increased. <P>SOLUTION: The method comprises a step of vertically driving the wooden pile so that the top surface of the wooden pile head portion is lowered to a lower level than the ground surface or the excavated ground surface, a step of throwing a soil pack filled with sand gravel onto the wooden pile, then pressing down the soil pack by compacting, pressing-in by vibration, or static pressing-in from thereabove, and repeating the throwing-in and pressing-down of the soil pack to press down the wooden pile so that the top surface of the wooden pile head portion is at a lower level than the groundwater level of a soft ground and a step of leveling the uppermost surfaces of the soil packs accumulated on the wooden pile to the ground surface or the excavated ground surface. <P>COPYRIGHT: (C)2012,JPO&amp;INPIT

Description

  The present invention relates to a method for placing a wooden pile. More specifically, the wooden pile is placed in the vertical direction of the soft ground to support the embankment and the superstructure without decaying, and by placing the wooden pile. The present invention relates to a wooden pile placing method capable of maintaining a dense ground, increasing horizontal earth pressure, increasing binding force, increasing drainage, and increasing the shear resistance of the entire ground.

  Environmentally friendly ground countermeasures are being carried out by placing wooden piles in the ground. In that case, the decay and insect damage of the wooden piles will be a problem. As a result of the excavation investigation and the laboratory experiment of the existing structure, if the wooden pile in the ground is below the groundwater, it is known that neither decay nor insect damage occurs. Therefore, the Building Standard Act enforcement order states that “when using wooden piles as the foundation of a building, the wooden piles must always be under the water surface, unless used for one-story wooden construction” . In general, when the upper part of a wooden pile driven into the ground is above the lower limit of groundwater fluctuation, the wooden pile is subjected to antiseptic measures using chemicals. If there is no decay, no insect damage will occur, so decay includes insect damage. However, in the case of anti-corrosion measures using chemicals, even if safety standards are satisfied, there are many concerns about safety regarding soil contamination and the like.

  The anti-corruption measures for wooden piles in Patent Document 1 are to apply an air blocking material to the portion of the wooden pile that goes above the groundwater level to form a covering part, or to place a wooden pile on the ground that has air blocking It is. The wooden pile is placed so that, for example, a portion that goes above the groundwater level becomes an air barrier layer. However, in order to cover the wooden pile part above the groundwater level so as to become an air barrier layer and not to cause decay, it is necessary to apply an air barrier material to many wooden piles, Since it takes time and effort to confirm whether there are any scratches or cracks on the wooden pile, there is a risk of increasing construction costs.

JP 2008-223379 A

  The purpose of the present invention is to prevent the decay of the wooden pile, and the ground becomes dense due to the placement of the wooden pile, the horizontal earth pressure increases, the binding force increases, the drainage increases, and the shear resistance of the entire ground increases. An object of the present invention is to provide a wooden pile placing method capable of maintaining an increased state.

The method for placing a wooden pile according to the present invention includes a step of vertically placing a wooden pile, and lowering the top surface of the wooden pile until it exceeds the ground surface or the ground surface dug down, and a soil material filled with gravel. Put the pack on the top of the wooden pile, tamped from the top of the soil pack, or press down by vibration press-fit or static press-fit, repeatedly insert and push down the soil pack, the top surface of the head of the wood pile is soft Pushing down to a position below the groundwater level of the ground, and making the uppermost surface of the soil pack stacked on top of the wooden pile to be in a state where there is no step with the ground surface or the ground surface dug down Are provided.

The method of placing a wooden pile according to the present invention is to place the wooden pile and push it down until the top surface of the wooden pile is below the groundwater level of the soft ground, and the ground surface or the ground surface dug down and the wood Since the space between the pile heads was filled with a soil pack, (1) the wooden piles are not decayed because they are below the groundwater level. (2) The compaction of the soil pack or gravel does not cause loosening of the surrounding ground, but the ground becomes dense due to the placement of wooden piles, the horizontal earth pressure increases, the binding force increases, and the drainage It is possible to maintain a state in which the shear resistance of the entire ground is increased. (3) The soil pack can stably transmit the load of the superstructure to the wooden pile in the long term. (4) Gravel soil packs can be manufactured at low cost. (5) Since the gravel is filled in the bag for the soil pack, it is not liquefied by the earthquake. (6) Since no chemicals are used, there is no concern about contamination .

It is the example which applied the construction method of the wooden pile by this invention to the embankment foundation. It is the example which applied the construction method of the wooden pile by this invention to a waterway foundation. It is explanatory drawing which shows the construction procedure of the construction method of the 1st wooden pile by this invention. It is explanatory drawing which shows the construction procedure of the placement method of the 2nd wooden pile by this invention.

  Hereinafter, a method for placing a wooden pile according to the present invention will be described with reference to the drawings.

FIG. 1 is an example in which the wooden pile placing method according to the present invention is applied to an embankment foundation. FIG.
Is a ground improvement work by driving the wooden pile 2 into the soft ground 5. The embankment 1 is constructed above the wooden pile 2. The head upper surface of the wooden pile 2 is driven by a driving machine so as to come to a position below the groundwater level of the soft ground 5. The space between the top surface of the wooden pile 2 and the ground surface is filled with the soil pack 3. The soil pack 3 is a bag of sand gravel. The wooden pile 2 is driven vertically into the ground.

  FIG. 2 is an example in which the wooden pile placing method according to the present invention is applied to a waterway foundation. The soft ground 5 is dug down so that the water channel structure 4 can be installed. The ground improvement work was performed by driving a wooden pile 2 vertically into the ground surface dug down. A water channel structure 4 is installed above the wooden pile 2. The upper surface of the head of the wooden pile 2 is at a position below the groundwater level of the soft ground 5. The space between the top surface of the wooden pile 2 and the ground surface is filled with the soil pack 3.

  FIG. 3 is an explanatory view showing a construction procedure of the first wooden pile placing method according to the present invention. In (A), a wooden pile 2 is driven by a driving machine, and the top surface of the wooden pile 2 exceeds the ground surface or the ground surface dug down (indicated by symbol F), and one soil pack 3 can be thrown in. Indicates that it can be pushed down to a certain extent. Reference sign K indicates the direction in which the wooden pile 2 is placed. (B) shows that the soil pack 3 is thrown into the upper part of the pushed-down wooden pile 2. FIG. (C) shows pushing down the wooden pile 2 further downward at the same time that the soil pack 3 is squeezed, for example, by striking. This may be done by vibration press-fit or static press-fit regardless of tamping. The tamping can be performed with an octopus of a log bar, as indicated by reference numeral S. It is desirable that the soil pack 3 does not contain much water. This is because it is hard to harden when there is a lot of moisture. Moreover, the air in the soil pack 3 is pushed out by tamping. The soil pack 3 can transmit the load of the superstructure to the wooden pile 2 stably in the long term. At the same time, the surrounding ground of the wooden pile 2 can be prevented from being loosened. (D) shows that the upper surface of the head of the wooden pile 2 has come to a position below the groundwater level (indicated by the symbol W) of the soft ground 5. Moreover, the uppermost part of the soil pack 3 pushed into the upper part of the wooden pile 2 is in a state in which there is no level difference from the ground surface or the ground surface dug down (indicated by the symbol F). Since the position of the groundwater level (W) fluctuates, it is placed so that the upper surface of the head of the wooden pile 2 comes below the lowest position.

  The driving depth of the wooden pile 2 can be managed by using the number of the soil packs 3 or the rod 6 made of iron or the like installed on the head of the wooden pile 2 or a string. The rod 6 has a length of a distance (L) between the ground surface (F) and the groundwater level (W) as shown in the drawing circle of FIG. This is driven into the side of the wooden pile 2 and fixed. The rod 6 may deteriorate and disappear with aging. If the upper end of the rod 6 is the same as the ground surface (F), it can be seen that the upper surface of the wooden pile 2 has reached the groundwater level (W).

  FIG. 4 is an explanatory view showing a construction procedure of the second wooden pile placing method according to the present invention. (A) shows that the wooden pile 2 has been driven by a driving machine, and the top surface of the head of the wooden pile 2 has reached the ground surface or the ground surface dug down (indicated by the symbol F). (B) further pushes down the wooden pile 2 with a driving machine, and shows that the upper surface of the head of the wooden pile 2 has come to a position below the groundwater level (indicated by the symbol W) of the soft ground 5. When the driving machine does not enter the hole, the wooden pile 2 can be pushed in by inserting a bar-like metal fitting that can be inserted into the hole. (C) shows that the soil pack 3 is put into the upper part of the pressed down wooden pile 2 and is compacted with an octopus (indicated by symbol S) as necessary. By compacting the soil pack 3, the air in the soil pack 3 is pushed out. In addition, when the input gravel does not spread around the hole, the soil pack 3 is not used, and the gravel may be directly input and compacted. In (D), the upper portion of the wooden pile 2 is filled with the soil pack 3, and the uppermost portion of the soil pack 3 has no level difference from the ground surface or the ground surface dug down (indicated by the symbol F).

  The soil pack 3 is filled with gravel, but crushed concrete waste or slag may be used. If you use uniform gravel with a large particle size, it is possible to avoid compaction and to fully transfer the load.

  The first wooden pile placing method is suitable when the soft ground is relatively soft. That is, the soil pack 3 and the wooden pile 2 can be pushed down by tamping, and the soil pack can be introduced in accordance with the distance until the upper portion of the wooden pile 2 is below the groundwater level. The second wooden pile placing method is suitable when the soft ground is slightly hard or when a large amount of energy is required for placing the wooden pile. Use the driving machine to drive until the top of the wooden pile 2 is below the groundwater level, and then put the soil pack 3 or gravel into the hole formed on the wooden pile 2 and compact it. Can do.

  The method of placing a wooden pile according to the present invention is intended to prevent the decay of the wooden pile, and the ground becomes dense, the horizontal earth pressure increases, the binding force increases, the drainage increases, and the shear resistance of the entire ground increases. This is suitable for improvement work on soft ground.

DESCRIPTION OF SYMBOLS 1 Embankment 2 Wooden pile 3 Soil pack 4 Water channel structure 5 Soft ground 6 Rod K Placing with a driving machine S Damping with a log stick F Ground surface or the ground surface dug down W Groundwater surface

Claims (1)

Placing a wooden pile vertically and lowering until the top surface of the wooden pile head exceeds the ground surface or the ground surface dug down,
Put the soil pack filled with gravel into the upper part of the wooden pile, squeeze from the top of the soil pack, or press down by vibration press-fit or static press-fit, repeatedly insert and push down the soil pack, Pushing down until the upper surface of the head is below the groundwater level of the soft ground,
A method for placing a wooden pile, comprising: a step in which an uppermost surface of the soil pack stacked on top of the wooden pile has no step with a ground surface or a ground surface dug down.

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