JP4485006B2 - Construction method for underground structures - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for constructing an underground structure under conditions where the groundwater level is high and existing underground structures exist.
[0002]
[Prior art]
When constructing an underground structure in the ground where groundwater exists, it is common practice to install a retaining wall that combines strength to prevent soil collapse and waterstop to prevent groundwater in order to excavate the underground part. .
[0003]
If the groundwater level is high, the existing underground structure is present, and there is no room to install a retaining wall between the existing underground structure outer wall line and the site boundary line, the construction method shown in Figs. Done.
[0004]
In the figure, reference numeral 1 denotes an existing underground structure after the ground structure is removed, and a portion 2 is backfilled 2 so that the digging machine 3 can be carried. You may give the slab reinforcement 4 as needed.
[0005]
This drilling machine 3 is a so-called rock auger having a capability of destroying underground structures. In the figure, 5 is an existing mountain stopper, and 6 is a temporary wall for backfilling 2.
[0006]
The excavator 3 destroys and drills the existing frame portion 1 of the underground structure, and constructs a mountain retaining wall 7 having a water stoppage for the soil cement column wall. This mountain retaining wall 7 is formed by pouring a soil cement into the hole by pouring a solidified material such as cement milk from the auger head of the digging machine 3 and stirring it with the excavation gap. Further, a core material 8 made of H-shaped steel or the like is incorporated.
[0007]
In FIG. 4, a is a site boundary line, b is an existing outer wall line, c is an existing inner wall line, d is a newly built outer wall line, a temporary enclosure 9 is installed on the site boundary line a, and the inside is a construction site .
[0008]
[Problems to be solved by the invention]
However, in the method as shown in FIG. 3 and FIG. 4, it is necessary to pierce the existing underground skeleton 1 of the underground structure with the digging machine 3 in advance, which requires a lot of time and cost. In addition, noise and vibration generated at the time of drilling are a big problem in urban areas.
[0009]
The object of the present invention is to eliminate the inconvenience of the conventional example, eliminates the need to install a large retaining wall having both water-stopping and retaining strength, shortens the construction period and reduces the construction cost, To provide a construction method for underground structures that eliminates the problems of noise and vibration during construction, helps prevent construction pollution in urban areas, reduces the generation of construction waste, and makes effective use of resources is there.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, the present invention constructs a thin wall that retains only water-stopping performance on the outer periphery of an existing underground structure until it reaches a position deeper than the existing underground structure, and constructs temporary beams and the like. Or, after refilling the existing underground enclosure or dismantling the existing underground enclosure and removing the slabs, pillars, and beams, the existing walls may be able to keep the outer wall independent. Without using the outer wall of the existing underground structure as a retaining wall, excavation necessary for the new construction, and installing a pile driver on the foundation bottom of the existing underground structure, Use the outer wall of the existing underground structure and the retaining pile as a retaining wall to perform excavation necessary for the new construction, and drill the hole in the foundation bottom of the existing underground structure in advance by core boring, etc. The gist is to cast Than is.
[0011]
According to the first aspect of the present invention, it is sufficient that there is a width between the existing outer wall line of the existing underground structure and the site boundary line so that a thin wall that holds only the water-stopping property can be installed. Uses the outer wall of the existing underground structure, so there is no need to drill the existing underground frame in advance and install a large retaining wall that has both waterproof and strength, shortening the construction period and reducing the construction cost Is achieved.
[0012]
According to the second aspect of the present invention, in addition to the above-described function, the pile pile installed by placing the pile driving machine on the foundation bottom of the existing underground structure has already been excavated for the newly installed underground structure. It is effective as a retaining wall when reaching below the underground structure, and the retaining pile set under this existing bottom can be a simple retaining structure that does not require water-stopping.
[0013]
According to the third aspect of the present invention, when the foundation pile of the existing underground structure is previously drilled by core boring or the like, the pile pile is made of a steel material such as H-shaped steel. It can be placed easily and quickly using a pile driver.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal side view showing an embodiment of a construction method for an underground structure according to the present invention, FIG. 2 is a plan view of the main part of the same, and in FIG. In Fig. 2, a is the site boundary line, b is the existing outer wall line, e is the inner surface of the existing foundation beam, d is the new outer wall line, and a temporary enclosure 9 is installed on the site boundary line a. It becomes a construction site.
[0015]
A thin wall 10 that retains only the water stopping performance on the outer periphery of the existing underground structure 1 of the existing underground structure is constructed until reaching a position deeper than the existing underground structure 1 of the existing underground structure. The thin wall 10 is basically composed of a soil mortar and a water shielding sheet, and various construction methods have been proposed. For example, it is called a trader construction method, and a continuous groove is formed with a chain saw type excavator, and cement milk is poured from the tip of the excavator to expand sales with excavated soil, filling the groove with soil mortar, and synthesizing this For example, a resin impermeable sheet is built with a weight attached to the lower end, or is pulled out from a storage section provided in the excavator.
[0016]
In particular, when the construction depth is deep, thin wall excavation can be performed using an excavator that excavates by adding rods.
[0017]
On the other hand, the outer wall 1a of the existing underground frame 1 of the existing underground structure can be used as a retaining wall. When the existing underground skeleton 1 is reinforced concrete, the outer wall 1a is also made of reinforced concrete and is composed of slabs, columns, and beams. However, the illustration of the outer wall 1a is omitted in order to give the outer wall 1a strength as a retaining ring. However, a temporary cut beam or the like is installed, or the existing underground structure 1 is backfilled, and a new structure is constructed by a reverse driving method.
[0018]
Even after dismantling the existing underground skeleton 1 and removing the slabs, columns, and beams, the existing pile 11 may keep the outer wall 1a independent. In that case, the outer wall 1a is a retaining wall without erection of a cut beam. It can also be used as
[0019]
However, when the excavation for the newly installed underground structure extends to the lower side of the existing underground frame 1, the outer wall 1a is surely lost its independence. Therefore, the pile driver 13 is installed on the foundation bottom 12 of the existing underground structure 1 of the existing underground structure, and the pile retaining pile 14 is laid, and the outer wall 1a of the existing underground structure and this pile retaining pile 14 are used as the retaining wall. Then, the existing underground structure 1 is dismantled appropriately, excavation necessary for new construction is performed, and excavation to the flooring surface is performed.
[0020]
In order to install the pile driver 13, a part of the existing underground frame 1 is disassembled as necessary to secure a space. It is. Further, the pile retaining pile 14 used as the retaining wall does not need a water-stopping property as the retaining wall, and a steel material such as H-shaped steel can be used. However, the base bottom plate 12 is previously provided with a hole 16 (core removal) by core boring or the like. After opening, the piles 14 are driven.
[0021]
When the low head pile driver is of the auger type, the H-shaped steel of the pile pile 14 may be built in the drilled hole and fixed with mortar, cement milk, or concrete.
[0022]
In this way, the thin wall 10 that retains only the water stopping performance is constructed in the vicinity of the site boundary line a, and the pile pile 14 is driven on the existing foundation beam inner surface e near the newly constructed outer wall line d. The mountain retaining pile 14 and the outer wall 1a of the existing underground structure bear the mountain retaining strength, and the thin wall 10 exhibits water blocking properties.
[0023]
【The invention's effect】
As described above, the construction method of the underground structure of the present invention uses two types of retaining walls, one that retains only water-stopping and the other that retains only strength, and uses a part of an existing underground structure. The function of the retaining wall can be achieved without pre-drilling the existing frame part in advance, and there is no need to install a large retaining wall that has both water-stopping strength and retaining strength. Reduction of noise and vibration during drilling is also eliminated, which helps to prevent construction pollution in urban areas, and can reduce the generation of construction waste and effectively use resources. It is.
[Brief description of the drawings]
FIG. 1 is a longitudinal side view showing an embodiment of a construction method for an underground structure according to the present invention.
FIG. 2 is a plan view of an essential part showing one embodiment of a construction method for an underground structure of the present invention.
FIG. 3 is a longitudinal side view showing a conventional example.
FIG. 4 is a plan view of a main part showing a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Existing underground frame 1a ... Outer wall 2 ... Backfill 3 ... Digging machine 4 ... Slab reinforcement 5 ... Existing mountain retaining 6 ... Temporary wall 7 ... Mountain retaining wall 8 ... Core material 9 ... Temporary enclosure 10 ... Thin wall
11 ... Existing pile 12 ... Foundation bottom
13 ... Pile driver 14 ... Screw pile
16 ... hole

Claims (3)

Build a thin wall that retains only water-stopping performance on the outer periphery of the existing underground structure until it reaches a deeper position than this existing underground structure , lay temporary beams, etc., or backfill the existing underground structure, Or, even after dismantling the existing underground structure and removing the slabs, columns, and beams, the existing piles may keep the outer walls independent. A construction method for underground structures characterized by excavation necessary for new construction by using as a retaining wall.   A pile driving machine is installed on the foundation bottom of an existing underground structure to place a pile pile, and the outer wall of the existing underground structure and the pile pile are used as a pile wall to perform excavation necessary for a new construction. The construction method of the described underground structure.   The method for constructing an underground structure according to claim 2, wherein a pile pile is driven after a hole is drilled in advance in the foundation bottom of the existing underground structure by core boring or the like.

Images