JPH0619136B2 - Slime removal device at the bottom of pile holes - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for removing slime accumulated at the bottom of an excavated pile hole when constructing a cast-in-place concrete foundation pile.

(Prior art and its problems) Conventionally, in order to remove slime accumulated at the bottom of the excavated pile hole, water is injected using a tremie pipe, or jet injection is performed by a hose or the like separately inserted into the pile hole. go,
Although slime removal methods such as preventing the precipitated state of slime by stirring the slime at the bottom of the pile holes have been performed, these conventional slime removal methods all require extra labor. There was a problem that the effect was not enough and it was not practical.

(Means for Solving Problems) In order to solve the above-mentioned problems, in the present invention, an annular pipe is provided around the lower end striking part of the tremy pipe for concrete pouring used when constructing a cast-in-place concrete foundation pile. In addition, a plurality of nozzles are arranged in the pipe in a substantially radial direction, and pressurized water can be supplied to the annular pipe to form a slime removing device at the bottom of the pile hole.

(Operation) As described above, according to the present invention, a slime removing device is configured by using a tremie pipe that has been conventionally required for placing concrete in the construction of cast-in-place piles, and the tremie pipe is installed in the pile hole. Just before inserting and placing concrete,
The pressure water is sprayed radially from the lower end of the tremie pipe to blow out the slime accumulated at the bottom of the pile hole, and concrete is placed immediately after that, so extra work is added to the conventional method. The slime can be removed easily, easily, and effectively.

Therefore, the device of the present invention has a simple yet effective operation effect, does not require extra man-hours, and does not get in the way even if there is a rebar cage inserted in the pile hole.

Embodiment An embodiment of the present invention will be described below with reference to the drawings. Reference numeral 1 in the drawing denotes a tremie tube located at the lowermost end according to the present invention.

In this embodiment, as shown in detail in FIG. 2, an annular groove 1a is formed on the outer periphery of the lower part of the tremie tube 1, and the annular groove 1a goes upward from two places (two positions 180 ° apart). A notched vertical groove 1b is formed, and an annular pipe 2 as shown in FIG. 3 is provided in the annular groove 1a. The tube 2 shown in FIG. 3 is formed in a semi-circular shape and is bolted through flanges 2a provided at the ends of the tube. Nozzles 3 are arranged at positions around the circumference 8 of the annular pipe 2, and the jet directions of these nozzles 3 are directed substantially in the radial direction.

In the case of the present embodiment, as shown in FIG. 3 (b), the ejection direction line B of the nozzle 3 is planar with respect to the accurate radial direction line A.
It is inclined at an angle of ゜, and in elevation, as shown in Fig. 4,
The injection direction line D of the nozzle 3 is inclined by 15 ° with respect to the horizontal line C.

Further, nipples 4 are provided so as to project upward at the central portions of the semicircular pipes 2.

Then, as shown in FIG. 1, an annular pipe 2 is fitted into the annular groove 1a of the tremie pipe 1 and is fixed by bolts 5 and nuts 6 through the flanges 2a thereof, and a hose 7 is attached to each nipple 4. A cheese 8 is connected between these hoses 7, and a hose 10 is connected to the cheese 8 via a coupling 9.

Next, a method of using the device of the present invention configured as described above will be described with reference to FIGS.

In the figure, 11 is the ground, 12 is a pile hole formed by excavating this ground 11, 12a is its expansion, 12b is the bottom of the pile hole, 13 is slime, 14 is a rebar cage inserted in the pile hole 12, 15 Is a casing provided in the upper part of the pile hole 12, and 16 is an upper tremie pipe which is added to the lowest tremie pipe 1.

As shown in FIG. 5, when the excavation of the pile hole 12 is completed, the scale is measured, the rebar cage 14 is installed, and then the tremie pipes 1 and 16 having the device of the present invention are inserted into the pile hole 12. As shown in FIG. 6, with the lower end of the tremie pipe 1 located near the bottom surface 12b, the high pressure pump 17 provided on the ground 11 is operated,
Nozzle 3 provided on the annular pipe 2 via the hoses 10, 7 etc.
Higher-pressure water (for example, 20 to 100 kg / cm ² ) is jetted radially along the bottom surface 12b.

In this way, the slime 13 accumulated on the bottom surface 12b is blown up as shown in FIG. 6, and as shown in FIG.
Place 8

In this case, since the slime 13 is in a state of floating above the bottom surface 12b, there is no possibility that the slime 13 remains on the bottom surface 12b of the pile hole 12 to reduce the bearing capacity of the pile. Incidentally, 19 in FIG. 7 is a concrete hopper connected to the upper end of the tremie pipe 16, and 20 is a chute for supplying the fresh concrete 18 to the hopper 19.

(Effects of the Invention) As described above, the present invention configures a slime removing device using a tremy pipe that has been conventionally required for placing concrete in the construction of cast-in-place piles, and uses the tremie pipe in the pile hole. Immediately before inserting into the concrete and placing concrete,
The pressure water is sprayed radially from the lower end of the tremie pipe to blow off the slime accumulated at the bottom of the pile hole, and concrete is placed immediately after that, so extra work is added to the conventional method. The slime can be removed easily, easily, and effectively.

Therefore, the device of the present invention has a simple yet effective operation effect, does not require extra man-hours, and does not get in the way even if there is a rebar cage inserted in the pile hole,
According to the present invention, it is possible to obtain an effect that a cast-in-place pile with a small amount of decrease in bearing force due to slime remaining can be easily obtained.

[Brief description of drawings]

 FIG. 1 (a) is a front view of a tremie tube provided with the device of the present invention, FIG. 1 (b) is a side view thereof, and FIG. 2 (a) is a front view of only the tremie tube of FIG. b) is a side view thereof, FIG. 3 (a) is an elevation view of an annular pipe of the device of the present invention, FIG. 3 (b) is a plan view thereof, and FIG. 4 is IV-IV of FIG. 3 (b). Sectional views and FIGS. 5 to 7 are explanatory views of the operation of the device of the present invention. 1 ... Tremy pipe, 2 ... Annular pipe 3 ... Nozzle, 4 ... Nipple 7,10 ... Hose, 11 ... Ground 12 ... Pile hole, 12b ... Bottom 13 ... Slime, 14 ... Reinforcement dragon 15 …… Casing, 16 …… Tremy tube 18 …… Green concrete

Claims (1)

[Claims] 1. An annular pipe is provided on the outer periphery of the lower end portion of a tremy pipe for concrete casting used when constructing a cast-in-place concrete foundation pile, and a plurality of nozzles are respectively directed substantially radially in this pipe. A slime removing device at the bottom of a pile hole, which is arranged so that pressurized water can be fed to this annular pipe.