JPS6037323A - Detection of sand face in underwater pack drain work - Google Patents

Abstract

PURPOSE:To form the column of sand bags without disconnection of sand by a method in which a ring of a smaller inside diameter than a casing is provided near the sand face of the casing and the ring is opened when the ring is filled with sand. CONSTITUTION:A casing 2 is driven into soft ground 1, and then a bottomed sand bag 3 is inserted into the casing 2. Sand S supplied through a sand supply hopper 5, a belt conveyer 6 and a chute 7, together with water W supplied from a water pipe 9 with a water regulating valve 8, is introduced into the sand bag 3 through the sand supply hopper 10. When the sand reaches the positions of sand face detectors 16A, 16B and 16C, each of which consists of an expandible ring, the ring of the detectors is expanded by the pressure of the sand S. When the sand face is lowered, the ring of the detectors is contracted.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting the sand surface of an underwater pack drain construction method in which sand bag pillars are formed in soft ground such as the bottom of a lake.

Conventionally, the sand drain method using sand pillars has been widely adopted as a construction method for improving soft ground such as the seabed.

However, as the length of the sand pillars increased, there were problems in construction, such as the sand pillars becoming thinner and discontinuous due to sand breaks during construction. Not only did it require a large amount of sand, but the drain effect was unstable and its reliability was questionable.

Therefore, when a casing is driven into soft ground such as a firm bottom and a sand bag is dropped into the casing, the water below the sand bag inside the casing is drained out through a drain pipe by a pump. The sandbag is allowed to sink into its casing while adjusting the drainage volume to form a sandbag pillar, and then the casing etc. are removed leaving only the sandbag pillar. An invention was made in Japanese Patent Publication No. 53-16604 regarding a construction method and apparatus for forming a .

However, even in this case, the position of the sand surface inside the sand bag that descends inside the casing cannot be seen from the outside at all, and as a result, if the sand bag settles slowly, the sand surface inside the sand bag rises and the sand becomes sandy. In addition, if the sand bag settles too quickly, water mixed with sand will not be properly drained, and sand with a high water content will form a sand bag, which is an undesirable problem.

Therefore, the present invention eliminates the above-mentioned conventional disadvantages, detects the position of the sand surface inside the sand bag from the outside, and makes it possible to adjust the amount of drainage from the bottom surface of the sand bag accordingly. The purpose of this invention is to enable the production of sandbag pillars with good quality without any defects, and to aim at efficient production of sandbags.

That is, the sand surface detection method of the underwater pack drain construction method of the present invention involves driving a casing into soft ground such as an oil bottom, and draining the sand bag inside the casing through a drain pipe while draining the water filled inside the casing. In the underwater panoctrane construction method, in which sandbag pillars are formed in soft ground such as an oil bottom by lowering them into the casinog and forming sandbag pillars, and then removing the casing, etc., leaving only the sandbag pillars, A ring with an inner diameter slightly smaller than the inner diameter of the casing is placed near the sand surface of the casing, and the link is expandable and contractable. When the ring is filled with sand, the ring expands and the sand is removed. A feature of the present invention is that when the sand does not exist within the ring, the ring contracts to detect the sand surface.

An embodiment of the present invention will be described below with reference to the drawings. Fig. 1 is an overall layout diagram of a sand column forming device to which the sand surface detection method of the underwater pack tray/construction method of the present invention is applied, and Fig. 2 1 is an enlarged side sectional view of the vicinity of the sand surface detector shown in FIG. 1, and FIG. 3 is a plan view of the sand surface detector shown in FIG. 2.

First, in the sand bag pillar forming apparatus shown in FIG. 1, the casing 2 is filled with water W while the casing 2 is driven into the soft ground 1 of the oil bottom to be improved.

A sand bag 6 with a bottom is inserted outside the casing 2, and the sand S supplied via the sand supply hopper 5, belt conveyor 6, and chute 7 is passed through the supply water pipe 9 having the supply water adjustment valve 8. Together with the supplied water W, it is introduced into the sand bag 6 via the sand supply holes 10.

As mentioned above, the sand bag 6 into which the wet sand S containing the supply water W is introduced from the sand supply hole (-10) is underwater in the casing 2, becomes P and descends, but inside the casing 2. The water W previously filled below the sandbag O is
Discharged water adjustment (The water is gradually discharged out of the casing 2 through the drain pipe 13 having the lubricant 12, and accordingly, the underwater tsukutsuku P becomes a sandbag column and descends inside the casing 2.

In addition, 14 in FIG. 1 is a separated water receiver, and 15 is a separated water outlet.

Further, a plurality of sand surface detectors 16A, 16B, and 115C are provided near the position of the created portion of the sand surface in the upper part of the casing 2.

These sand surface detectors 16A, 16B, and 16C are composed of a plurality of pieces, for example, three pieces, as shown in FIGS. 2 and 3.
If the diameter of this sandbag pillar is D, then a ring with a slightly smaller inner diameter d is divided into two parts, one end of both parts is rotatably connected with a hinge 18, and the other end is By connecting them with a spring 19, the two rings are kept lightly pressed against each other, and this ring can expand and contract according to the pressure of the sand in the sand bag 3.

Therefore, sand S is put into the sand bags 6 near the sand surface detectors 16A, 16B, and 16C, and the sand surface rises upward and reaches the positions of the sand surface detectors 16A, 16B, and 16C. Then, the two members are expanded outward due to the pressure of the sand S, but at this point, the two members are made not to open beyond the diameter of the sand bag pillar, and when the opening is detected, a lamp, signal, or other The operator can be notified by the following means.

On the other hand, if the sand level falls, the internal pressure disappears, and the rings of the sand level detectors 16A, 16B, 16C contract and return to the diameter d, indicating that the sand level has fallen.

Note that the sand surface detectors 16fi, 16B as described above.

16C detects the position of the sand surface, sends the signal to a control device (not shown), and this control device controls the discharge adjustment valve 12 to control the discharge water W filled into the Goo Song 2.
You can also adjust the amount of drainage.

That is, if the position of the sand surface in the sand bag 6 is too high, the amount of drainage is increased manually or automatically to hasten the descent of the sand bag column, and if the position of the sand surface is too low, the amount of drainage is increased. The descent of the sandbag column can be delayed by reducing it manually or automatically.

Note that the number of sand surface detectors 16A, 16B, and 16C and the expansion/contraction method of their ring members are not particularly limited, and the method of adjusting the drainage amount after detection is also not limited to this embodiment.

Further, after the sandbag pillars are formed as described above, the casing 2 is removed leaving only the sandbag pillars as is the case with the conventional method.

Therefore, if the present invention is applied to the underwater pack drain construction method, it will be possible to create sandbag pillars of good quality without any sand particles, and it will also be possible to automate the sandbag pillar forming device using a control device. It is also possible to drive the vehicle, which has the effect of reducing labor costs.

[Brief explanation of the drawing]

Figure 1 is an overall layout of the sand column forming device to which the sand surface detection method of the underwater pack tray/method of the present invention is applied, and Figure 2 is the overall layout of the sand column forming device.
FIG. 3 is an enlarged side sectional view of the vicinity of the sand surface detector shown in the figure, and FIG. 3 is a plan view of the sand surface detector shown in FIG. 1... Soft ground, 2... Casing, 6... Sand bag, 1
2...Drainage adjustment valve, 16...Drain pipe, 16A
. 16B, 16C...Sand level detector, 18...Hinge, 19...Spring, D...Diameter of sand column, d...Inner diameter of ring, W...Water, S... sand.

Claims (1)

[Claims] A casing is driven into soft ground such as the seabed, and while the water filled in the casing is discharged through an exhaust pipe, the sand bag inside the casing is lowered into the casing to form a sand bag pillar. In the underwater punk drain construction method, in which sand bags are formed in soft ground such as the seabed, the casing, etc. is removed leaving only the casing, etc. A ring is positioned so that the ring can be expanded and contracted, and when sand is filled in the ring, the ring expands, and when sand is not present in the ring, the ring contracts and detects the sand surface. A sand surface detection method for underwater pack drain construction method.