JPH02132228A - Process of building heavy-duty working floor using existing basement structure - Google Patents

Abstract

PURPOSE:To aim at simplifying the dismantling work of a building by dismantling floors, beams and the like of an existing first basement, and by successively laying and stacking steel grand beam sleepers, floor joints and cover plates between support columns so as to build a heavy-duty working floor onto which a heavy machine or the like can ride. CONSTITUTION:After floors, beams and the like of the first story and those existing down to the floor of the first basement are dismantled, then the ceiling end level is adjusted by use of mortar 8, and receiving seats 9 are secured by means of anchors 7 with the use of nuts. Then, steel grand beam sleepers 10 are laid bridging between the receiving seats 9 in two stages and then are secured by nuts, and thereafter, steel floor joists 11 are laid on the sleepers 10. Further, cover plates are laid on the joists 11. Concrete outer guide walls 14 are built at predetermined intervals on the outside of an outer wall 2 of an existing basement structure 1 so as to form guide pits C for building a ground retaining wall between the outer guide wall 2 and the guide walls 14. Further, the ground in the outer wall 2 is excavated more deeply by a heavy machine B which has ridden onto a heavy-duty working floor A so as to build a ground retaining wall 3. With this arrangement, it is possible to inhibit underground water from flowing into the basement during construction for ground retaining.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides for the purpose of dismantling an existing building and constructing a new building on its site, by moving heavy machinery used for pile work, piling work, etc. within the site ( This relates to techniques for constructing a heavy-duty work floor for accessing a former site.

[Conventional technology]

In recent years, in the case of construction work in urban areas, it is no exaggeration to say that there is almost no new construction work on vacant land, and there are many cases of demolishing existing buildings and rebuilding new ones.

In addition, in urban areas, underground structures are often built to fill the entire site, and in this case, it is not possible to carry out secondary mountain latch construction or pile construction from the surrounding area, and once the above-ground building is dismantled, pile stop work must be carried out. Heavy machinery used for such purposes will be brought onto the premises.

In such cases, conventionally, the area below the first floor floor was backfilled with earth and sand, and a portion of the first floor floor was used as a heavy-load work floor on which heavy equipment could be accessed.

[Problem to be solved by the invention]

However, the above conventional method is relatively easy to apply if the underground structure is about the size of one basement floor.
When the basement floor is deep, such as 2 or 3 stories, the floors on each floor become obstacles, and backfilling with earth and sand is extremely difficult and takes a lot of effort. , the existing underground structure must be dismantled and the backfill earth and sand must be removed at the same time, which will inevitably lead to a significant increase in construction time and construction costs.

In view of the above-mentioned conventional drawbacks, it is an object of the present invention to make it possible to construct a heavy-load working floor easily and at low cost by utilizing an existing underground structure.

[Means for Solving the Problems] The technical means taken by the present invention to achieve the above object are as follows. That is, the heavy-load work floor construction method using an existing underground structure according to the present invention is such that after the above-ground building is dismantled, the pillars of the existing underground structure are left at the required height, and 1.
Floor of the floor. Beams, etc. are dismantled, steel joists are erected between the pillars, steel joists are erected on top of the joists, and lining boards are laid on top of the joists to allow heavy machinery to enter. It is characterized by the construction of a heavy-load work floor. When constructing a retaining wall using heavy machinery on the above-mentioned heavy-load work floor, the outer wall of the existing underground structure is used as an inner guide wall, the outer ground is excavated, and a position below the lower end of the outer wall is excavated. It is possible to build a wall that reaches up to a mountain.

(Function) According to the above configuration, since the inside of the existing underground structure is not backfilled with earth and sand, construction is easy and backfilling is possible even if the existing underground structure is as deep as 2 or 3 floors underground. Since there is no need to remove earth and sand, the existing underground structure can be easily dismantled.

Additionally, even if an abnormal situation occurs on the floor of the existing underground structure during construction, there is a space inside, so it can be dealt with quickly.

〔Example〕

Hereinafter, an embodiment of the present invention will be explained based on the drawings. Fig. 1 shows a state in which a retaining wall 3 is constructed on the outside of an outer wall 2 of an existing underground structure 1 constructed by the submerged box construction method. A is a heavy-load work floor installed using the existing underground structure 1. 4
5 is a cast-in-place expansion shaft that will serve as the foundation pile for a new building with a larger underground structure that will be constructed on the site, and 5 is a deep well for water drainage.

The heavy-load work floor Δ is constructed as follows.

That is, as shown in Fig. 2, after the above-ground building is dismantled, the floor, beams, and inner walls of the first basement floor are replaced with the first basement floor, with the columns 6 of the existing underground structure 1 remaining at the required height. Disassemble until.

After that, an anchor 7 is driven into the top end of the pillar 6, mortar 8 is applied to adjust the top level, a receiving seat 9 is installed, and a nut screwed onto the anchor 7 is tightened and fixed.

Next, after spanning two stages of steel joists 10 over the receiving seat 9 and fixing them with bolts and nuts, a steel joist is placed on the IO! 1) and integrally connect the joists 1) with horizontal steel channel members 12, and lining plates 13 are laid on the joists 11.

As a result, as shown in FIGS. 1 and 2, a heavy-load work floor A onto which heavy machinery B can be mounted is constructed.

In addition, W in FIG. 2 indicates the groundwater level.

Then, as shown in FIG. 2, an outer guide wall 14 made of concrete is constructed on the outside of the outer wall 2 of the existing underground structure 1 with a predetermined gap, and between it and the outer wall 2 is used for constructing a retaining wall. , a guide pisoto C is formed.

In this state, the heavy equipment B that has entered the heavy-load work floor A excavates the ground of the outer wall 2 of the existing underground structure 1 to a position deeper than the lower end of the outer wall 2, using the outer wall 2 as an inner guide wall. , reinforcing, and placing 27 concretes to construct a retaining wall 3 consisting of an underground continuous wall as shown in FIGS. 1 and 3.

After constructing the retaining wall 3, drainage will be carried out through the deep well 5 to lower the groundwater level, the existing underground structure (2) will be dismantled, and a new building with a large-scale underground structure will be constructed.

In addition to the underground continuous wall, the retaining wall 3 may be constructed of a row of fill pile columns or the like.

〔Effect of the invention〕

Since the present invention has the above-described configuration, it can achieve the following effects. ■Since the columns of the existing underground structure are used as supports for the heavy-load work floor, there is no need for temporary supports for the heavy-load work floor, and the space inside the existing underground structure is not backfilled with earth and sand. Even if the underground structure is deep, such as 2 or 3 stories underground, construction is easy and there is no need to backfill and remove earth and sand, making it easy to dismantle the existing underground structure.
■Even if an abnormal situation occurs on the floor of the existing underground structure during construction, there is a space inside, so it can be dealt with quickly. ■According to claim (2), since the outer wall of the existing underground structure is used as the inner guide wall, it is possible to not only reduce the construction effort and cost of the inner guide wall, but also reduce the excavation work for the retaining wall. Inside, the existing underground structure maintains a water-stop state, and even if the groundwater level is high, groundwater will not flow into the inner space during the heaping work.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and Fig. 1 is a schematic sectional view of the entire structure in which a retaining wall has been constructed on the outside of the outer wall of an existing underground structure, and Fig. 2 is a state in which a heavy-load work floor has been constructed. Fig. 3 is a sectional view of the main part in a state where the retaining wall is constructed. A... Heavy load working floor, B... Heavy equipment, l... Existing underground structure, 2... Exterior wall, 3... Mountain retaining wall, 6...
Pillar, IO...Ohiki, 1)...Joist, l3...Temporary lining. Applicant: Takenaka Corporation

Claims (2)

[Claims] (1) After dismantling the above-ground building, the floor, beams, etc. of the first floor will be dismantled, leaving the pillars of the existing underground structure to the required height, and steel bridges will be erected between the pillars. A heavy-duty construction using an existing underground structure characterized by constructing a heavy-duty work floor that can accommodate heavy machinery by erecting steel joists and laying lining plates on top of the joists. Work floor construction method. (2) After dismantling the above-ground building, the floor, beams, etc. of the first floor will be dismantled, leaving the columns of the existing underground structure to the required height, and steel bridges will be erected between the columns. Steel joists are erected for the pull-up, and lining plates are laid and lined up on top of the joists to construct a heavy-duty work floor that can accommodate heavy machinery. Heavy load using an existing underground structure characterized by excavating the outer ground using the outer wall of the underground structure as an inner guide wall and constructing a retaining wall that reaches a position below the lower end of the outer wall. Work floor construction method.