JPS5873618A - Constructing method and structure of foundation pile with expansion tip using ready-made pile - Google Patents

Abstract

PURPOSE:To easily construct a foundation pile with an expansion tip by a method in which precast piles including an expansion tip pile are connected with one another and they are hung down into a pit. CONSTITUTION:A combination of an expansion tip pile 21 and a pile 31 is hung down into a pit 10 filled with mud water. In case where the depth of the pit 10 is deep, they are hung down into the pit 10 while connecting the pile 21 with the pile 31, and cou0led in such a way that the upper end of the pile 20 is left in a proper length on the ground surface. In this way, piles are orderly connected as needed and hung down into the pit 10. After the expansion tip pile 31 lands on the pit bottom 13, cement mortar is poured into the aperture between the pile 20 and the pit 10 by means of a mortar pump MP to fill up the aperture and thereby fix the plle 20. Thus, a foundation pile with an expansion tip can be constructed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for constructing a foundation pile by combining and connecting a plurality of ready-made antibodies, and a foundation pile structure thereof.

Recently, expanded-bottomed piles have been increasingly used as foundation piles for buildings. Due to the partial revision of the Building Standards Act in June 1981, an increase in the load from the superstructure naturally occurred. In this case, the foundation piles of the structure will need to have a large diameter due to the need to hold the load. by the way.

Considering the ideal antibody, it is economically more suitable to use an expanded-bottom type pile that can achieve the same strength of the antibody and the strength of the ground than a simple straight-through type pile. It is certain. Therefore, the shift to "expanded-bottom" piles is expected to become more pronounced in the future.

Regarding the expanded bottom pile construction method that has been put into practical use, so far, 6
There are various construction methods. These construction methods are superior to conventional direct-produced piles in terms of antibody function.

9. From the aspect of construction implementation. ,・・From the aspect of construction cost.

Furthermore, from the point of view of the actual function of pile excavation after construction, no matter which construction method was adopted, it was not satisfactory.

For example, in the currently available cast-in-place piles, the lowest part of the hole is excavated so as to widen, and concrete is poured into the hole. However, in this case, it was difficult to confirm the shape of the excavated expanded bottom, and there were also problems with the method of detecting slime at the bottom of the hole, the method of arranging reinforcement in the expanded bottom, and the method of removing slime. Ta.

Furthermore, as a prior invention by the present applicant, a patent application was filed on January 18, 1972 (Japanese Patent Application No. 8312, 1972) for other expanded-bottom foundation pile construction methods, and the application was published on November 29, 1971 (Showa 54-8312). 39.551) There is an invention that was made. However, in this case, when pouring concrete, it is necessary to erect a formwork inside the casing and then pull out the formwork while pouring concrete, which poses a problem. Furthermore, both methods were sufficiently economical in terms of general pile costs, and the ratio was not 1:1.゛The purpose of the present invention is to provide a new method for constructing expanded-bottomed piles that eliminates the drawbacks of such conventional methods, and at the same time, this new method corresponds to an improvement of the method of the prior invention by the present applicant. do.

Another object of the present invention is to provide a foundation pile construction method that is implemented by combining and combining ready-made antibodies, a direct type type and an expanded type type, in order to eliminate the drawbacks of conventional construction methods. It is.

Another object of the present invention is to provide a foundation pile structure itself, which is made by combining and bonding ready-made antibodies of a straight-through type and an expanded-bottom type.

In order to achieve the above-mentioned object of the present invention, a pile is constructed according to the following procedure. First, use a drilling tool to drill a hole in the ground, make the diameter of this hole slightly larger than the diameter of the expanded bottom of the bottom end of the expanded-bottom pile that will be used, and install a pile turret above the hole. Then, a ready-made expanded-bottom pile body, which has a shape that widens toward the bottom near the lower end and whose upper part is equal to the diameter of a regular cylindrical body with a predetermined length, is placed on the ground near the hole. In the first step, a ready-made cylindrical normal type antibody of a predetermined length is brought above the expanded bottom pile body, the upper end of the expanded bottom pile body and the lower end of the normal type antibody are connected, and this is used to erect the pile. If the length of the pile connected in this way is shorter than the depth of the drilled hole, and therefore the lower end of the expanded pile does not reach the bottom of the hole, Fix the pile so that the top end is slightly above the ground, connect the bottom end of another ready-made normal type antibody to the top end of the previous normal type antibody, and insert 1-1 into the hole.
3 Grate. In this way, connect the ready-made ordinary antibodies one after another according to the depth of the hole, and then drop them into the hole, and finally, the bottom end of the ready-made antibody with its flared ends will be at the bottom of the hole. reach it. It is thus accomplished to construct a series of lengths of foundation piles in the hole, made up of a plurality of prefabricated antibodies connected.

On the other hand, with this pile construction method, a ready-made expanded-bottomed pile body having a widened-bottomed end portion at the lower end portion is provided, and one or more ordinary cylindrical antibodies of a predetermined length are mounted above the pile body. A ready-made antibody-connected foundation pile structure will be provided.

In order to further clarify the present invention, the method for constructing a foundation pile and the structure of the foundation pile according to the present invention will be described below with reference to Examples and drawings.

Figure 1 shows the hole drilled using the reverse method. Although it is possible to excavate the hole without relying on the reverse method, this method was used because it is simple and efficient. In this case, the diameter of the excavated hole is set to be slightly larger than the diameter dw of the enlarged bottom end of the pile, which will be described later, for example, 10 to 20 cf/L. G and L in Figure 1.

is the ground surface, and 12 is the muddy water inside the hole. Next, process the slime using a tremie tube.

Next, a pile erected turret (not shown) is set over the hole, and a small amount of concrete 16 is placed at the bottom of the hole.

However, the feature of the present invention is to connect and combine ready-made antibodies, including a widened antibody.

In addition, these are suspended into holes to construct foundation piles.

Therefore, first, the expandable bottom pile body that becomes the bottom end of the pile will be explained. FIG. 2 is a diagram showing the construction of the foundation pile of the present invention in progress, and what is shown at 21 at the lower end of this antibody is an expanded bottom pile body.

This expanded-bottomed pile has a stocky form with a diameter greater than its length, and its lower end 26 has a diameter dW smaller than the diameter of the hole. Above the lower end 26 is a portion 22 which flares out or defines the shape of a portion of a cone. Further above, a portion 24 having the same diameter do as the cylindrical pile body 31 is formed. Such an expanded bottom pile body 21 may be manufactured including framed reinforcing bars. Also, this product can be manufactured in a shape in which the bottom is closed, as shown by '2'5. In this case, a ventilation hole 26 may be provided in the bottom portion 25 in order to cancel out the buoyancy that would occur if the antibody was hollow when the antibody was lowered into the hole 10 filled with muddy water 12.

In the case of the present invention, such an expanded pile body 21 is made of concrete and is manufactured in a factory. These ready-made expanded-bottomed pile bodies are then transported to construction sites and used.

Also, what is shown by 1, 52, 33, and 34 in FIG. 2 is a factory-produced ready-made cylindrical (diameter d.) commercially available, standardized concrete antibody of a predetermined length.

When installing antibodies (indicated by 20) into the hole 1o, first, the expanded-bottomed pile body 21 is brought to the ground near the hole.

Next, a ready-made cylindrical pile body 61 of a predetermined length is brought above the expanded bottom pile body 21, and the upper end 22 of the pile body 21 and the pile body 6
1 by either welding or tensioning of PC steel wire. Next, the combined body of the expanded bottom pile body 21 and the cylindrical pile body 61 of a predetermined length is lowered into the 1° hole using the above-mentioned construction tower. At this time, the turret may be provided with an appropriate device that can lock the descent of the pile, and by using this locking device, the upper end of the pile body 61 slightly protrudes above the ground. I'll stop this at some point.

The above is necessary when the depth of the hole is deep and the lower end of the expanded pile body 21 does not reach the bottom of the hole. In other words, it reaches the bottom. If the hole is deep and the pile is still short, then a second unit pile body 62 of a cylindrical shape with a predetermined length is inserted into the pile body 3.
1, and the upper end of the pile body 61 and the lower end of the pile body 62 are firmly connected by welding or tensioning of PC steel wire.

Furthermore, ready-made antibodies made in this way30,31
The combined body of
0 so that the upper end of the pile body 62 remains on the ground above the hole for an appropriate length.

Stop and lock this.

In this way, individual antibodies 53, 34, . If necessary, connect the upper and lower ends of the pile bodies on the sides one by one using the same method as described in 1 above, and lower them into the hole.

FIG. 3 shows a state where the foundation pile body 20 has been erected into the hole 10. In this case, it will be seen that four cylindrical antibodies 31 to 64 are connected to the expanded bottom pile body 21 to complete one foundation pile body 2o.

Next, the gap between the pile body 20 and the hole 10 is filled with mortar or other equivalent material, and the pile body 20 is fixed (using an MP (mortar pump) as shown in FIG. 6). This means that construction of one foundation pile has been completed.

Also, the sequential steps of the method for constructing one foundation pile by connecting multiple pieces of ready-made antibodies as described above, ), ka, ra,! 11
Ka, nayoun...,, o, □, 7. From the viewpoint of Yoga 11, the ready-made expanded-bottom pile body 21, which is formed with a pile bottom end that is widened as far as possible and becomes the bottom-expanded end of the pile, is the lowest end, and above it is a pre-made cylindrical predetermined column. A ready-made antibody-connected base pile structure is provided, which is formed by connecting one length 31 or a plurality of other individual antibodies 32, 33, etc. In this case, the connection of each prefabricated antibody is made by first applying the foundation pile construction method to the upper end of each "prefabricated antibody and T", I, 9 by welding or by tensioning the PC steel wire (as mentioned above). !
・Ru.

In addition, the number of prefabricated antibodies to be connected is In the structure, piles with a length of 11 times per house are installed on the ground with a total of +1
It is also possible to use one constructed by - ti' I.

Furthermore, in the foundation pile construction method and foundation pile structure of the present invention, the antibodies of the structural units are applied in advance to surface treatment for preventing negative friction 1111+
・Apply and place the material (not shown) and connect the antibodies of this unit to construct the foundation pile. Therefore, the surface treatment can be carried out easily and effectively, and since the surface-treated pile body is installed in the form of a pile, unlike a planted pile, it is possible to reliably prevent negative friction. It can be effective.

The present invention relates to a method of constructing a foundation pile and a foundation pile structure as described above, and has the following effects.

That is, since the pile material is ready-made from a factory, high strength and homogeneity can be obtained. Furthermore, ready-made pile materials have improved due to improved manufacturing methods.

Since piles with higher strength are being supplied to the market, the use of ready-made piles may be advantageous in this respect.

This means that it is possible to use pile materials with a relatively small outer diameter.

This will also work towards reducing the cost of construction of foundation piles.

In addition, in this foundation pile, a reinforcement can be used as the lowest bottom expansion pile material, and a type with a fixed form can also be used. Since it is not a cast-in-place concrete pile, there is no mixing of muddy water into the pile material, thus increasing reliability in the quality of the pile material. Negative friction can be effectively prevented when the pile material is surface treated. When erecting pile materials into a hole, an adjustment mechanism can be provided in conjunction with the pile erecting turret, and by using this, it is possible to easily maintain the verticality of the pile.

In the foundation pile of the present invention, it is possible to determine the shape and dimensions of the expanded bottom end so that the strength of the antibody is the same as the strength of the ground, so it is economically cheaper and more advantageous than other construction methods. be.

[Brief explanation of drawings]

Figure 1 is a vertical cross-sectional view of a hole drilled in the ground into which a foundation pile can be installed, and Figure 2 is a vertical cross-sectional view showing the middle of the hole in which the foundation pile of the present invention is being installed. FIG. 6 shows the foundation pile of the present invention being lowered into the hole described above until it reaches the bottom of the hole, and the surrounding area of the pile is backfilled with mortar or a similar product. FIG. [Explanation of symbols of main parts] r), L, -... Ground surface 10... Hole 21... Ready-made expanded bottom pile bodies 61 to 64... Ready-made cylindrical piles of a predetermined length Pile body 20...Foundation pile Applicant: Mitsubishi Construction Co., Ltd. No. 11, No. 2gi, No. 3

Claims (1)

[Claims] 1. A hole is excavated in the ground using a drilling tool, the diameter of this hole is slightly larger than the diameter of the lower end of the pile, and a pile turret is installed above the excavated hole. Then, a ready-made expanded-bottom pile body formed with a bottom end of the pile that is widened as far as possible, which will become the bottom-expanded tip of the pile, is brought to the ground near the excavated hole, and a ready-made cylindrical shape with a predetermined length of 9 degrees is brought to the ground near the excavated hole. Bring the first antibody above the expanded bottom pile body, connect the upper end of the expanded bottom pile body and the lower end of the first antibody, and suspend the connected antibody into the hole in the ninth step to expand the bottom. If the enlarged bottom end of the pile body has not reached the bottom of the hole, suspending the connected antibody is appropriately stopped, and a ready-made cylindrical second antibody of a predetermined length is placed above the first antibody. bringing about the upper end of said first antibody and said second antibody.
and the lower end of the antibody, and then extend the length of the antibody according to the depth of the hole in the same way. The connected antibody is quickly lowered into the excavated hole by the tank, and the expanded bottom end of the expanded bottom pile body is made to reach the bottom of the hole. How to construct foundation piles. 2. A ready-made expanded-bottom pile body formed with a bottom end of the pile that can be expanded toward the end, which becomes the expanded-bottom tip of the pile, is the lowest end, and one or more ready-made cylindrical antibodies of a predetermined length are placed above it. A ready-made antibody-connected foundation pile structure characterized by being made by individually connecting each other.