JP2524654B2 - Kason deposition method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention relates to a caisson laying method used when constructing, for example, an underground multistory parking lot, and particularly to a caisson lower portion for laying a caisson. It relates to the improvement of the method of excavating the ground.

<< Conventional Technology >> A caisson is sunk by excavating the ground below the caisson lower end (blade mouth) to weaken the tip resistance of the caisson, and by the weight of the caisson body and loading. The conventional caisson digging method employs a total digging method in which the entire ground at the inner peripheral portion of the cylindrical caisson is excavated and dug. The caisson excavator used for that purpose uses a rotary excavator that matches the size of the caisson.The excavator is installed so that it can be hung from above in the center of the caisson, and the caisson internal Along with excavating the earth and sand, the bottom expansion bit is operated at the bottom of the excavation hole to expand the diameter of the hole to the outside, and the earth and sand under the caisson blade is also excavated. The caisson is sunk along the hole that extends under the blade.

<Problems to be solved by the invention> Conventionally, the method of excavating the entire ground inside a caisson with a rotary excavator is applied to a cylindrical caisson, but a square tube with a square or rectangular cross section. In the case of shaped caisson, it is not possible to dig the entire ground inside the caisson with a rotary excavator. In addition, even with a cylindrical caisson, in the case of a large caisson with a large diameter, an extremely large excavator is required to excavate all the ground inside with a rotary excavator, and in reality A caisson with a length of 5m or more cannot be handled by a rotary excavator.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a caisson digging method that can easily cope with a square tube-shaped caisson and a large caisson having a large diameter.

<< Means for Solving the Problem >> Therefore, in the present invention, by excavating the ground in a groove shape along the inner circumference of the cylindrical caisson, and widening the groove hole on the outer peripheral side inside the groove, the blade of the caisson I tried to dig the mouth and sunk the caisson.

<Operation> Even if the cross-sectional area in the cylinder is large, the ground is excavated along the inner circumference of the caisson instead of excavating the entire ground in the cylinder. Therefore, the caisson has a rectangular cross-sectional shape. Even if it is large or large, excavation work will not be very large.

<< Embodiment >> FIG. 1 shows an embodiment of the caisson depositing method of the present invention. In this example, a square frame-shaped caisson 2 is installed at a predetermined position on the ground 1, and the ground 1 is placed along the inner wall surface of the caisson 2.
Excavate in a groove. Reference numeral 9 indicates a groove hole that has been excavated.

For the excavation of the slot 9, for example, the Kerry type excavator 3 is used.
The excavator 3 is attached to the lower end of the vertical support shaft 6, and the caisson 2
The slot 9 is excavated along the inner wall of the.

Further, a widening drive unit 5 having a widening excavating blade 4 is attached to the upper portion of the Kelly type excavator 3. The digging blade 4 is for widening the groove hole 9 to the outside, and is oscillated by the drive unit 5 to dig the outer surface of the groove hole 9 formed by the excavator 3 with the digging blade 4 to remove the hole. It is designed to expand the width to the outside. Reference numeral 10 denotes a widening portion excavated by the widening excavating blade 4.

Since the slot 9 is formed along the inner wall surface of the caisson 2 and the widened portion 10 is formed outside the slot 9, the widened portion is formed.
10 is formed under the blade of the caisson 2. After forming the slot 9 so as to make a round along the inner wall surface of the caisson 2, the widened portion 10 is formed so as to make a round along the bottom of the blade of the caisson 2, and the caisson 2 is sunk in the ground 1.

If the caisson 2 cannot be smoothly submerged by the weight of the caisson 2, the jack 8 is attached to the frame 7 installed on the surface of the ground 1, and the caisson 2 is pressed downward by the jack 8 to reduce the pressing force and the caisson. With the weight of 2, the caisson 2 is inserted into the slot 9 and the widened portion 10
Let it sink as if you push it inside.

<< Effects of the Invention >> As described in detail above, in the caisson digging method according to the present invention, instead of excavating the entire ground inside the caisson, it excavates in a groove shape along the inner circumference of the caisson, and Since the hole is widened inside the caisson to excavate under the blade edge, it can be carried out with no problems with square cylindrical caisson or cylindrical caisson. Since the excavation work is relatively small, the required ground excavation work can be efficiently performed by using a small-scale excavator, and therefore caisson deposition can be efficiently performed.

[Brief description of drawings]

FIG. 1 is a schematic view of a caisson laying method according to an embodiment of the present invention. 1 ... Ground, 2 ... Caisson 3 ... Kelly type excavator, 4 ... Widening excavating blade, 5 ... Widening drive unit, 6 ... Support shaft, 7 ... Frame, 8 ... Jack, 9 ... Groove hole , 10 …… Widened part

Claims (1)

(57) [Claims] 1. The excavation of the ground in the shape of a groove along the inner circumference of a tubular caisson, and the expansion of the groove on the outer peripheral side inside the groove excavates the bottom of the caisson blade to dig the caisson. Caisson construction method characterized by doing.