JP2816593B2 - Underground diaphragm wall back pressure measuring instrument and its mounting method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a water pressure measuring instrument on the back of a continuous wall in construction work of an underground continuous wall, and a method of mounting the measuring instrument.

[Related Art] It is well known that the underground continuous wall method is widely used as a water blocking wall, a retaining wall, and a structural wall.

[Problems to be solved by the invention]

By the way, in this underground diaphragm wall method, measuring and managing the vertical stress and horizontal displacement, including the verticality of the constructed diaphragm wall, is important not only for construction management but also for constructing a higher-quality diaphragm wall. It is very important.

Incidentally, at present, when measuring the vertical stress, the horizontal displacement, and the like of the continuous wall, the measurement is generally performed using a strain gauge or an inclinometer.

By the way, in the measurement with this strain gauge or inclinometer, it is necessary to attach the elements of these measuring instruments to the measurement position in advance, and when the measurement requires specialized technical knowledge, field workers can easily It is not measurable.

Based on this situation, the present invention measures the back water pressure, which is one of the major load factors on the continuous wall, to obtain data useful for upgrading the continuous wall technology, including data on construction management. It is an object of the present invention to provide a back water pressure measuring device and a method for mounting the measuring device.

In particular, the aim is to provide a measuring instrument that can be used in any underground continuous wall construction site by a site worker with a simple operation, and a mounting method thereof.

[Means for solving the problem]

As means for achieving the above object, the present invention is configured as follows.

First, the back wall pressure gauge of the continuous wall was composed of a water nozzle for groundwater and a water level pipe.

That is, the water nozzle for groundwater was attached to the wall adjacent to the root of the underground continuous wall by penetrating the wall. Next, the lower end of the water level pipe was connected to the water-guiding nozzle for communication. At that time, the water level pipe is formed by using a water level pipe made of a transparent material so as to be able to check the water level from the outside, and is vertically arranged along the wall surface of the continuous wall.

Further, as a means for attaching the water guide nozzle to a wall surface close to the root cutting bottom of the underground continuous wall, the water guide nozzle is attached with the following water seal structure.

That is, first, a perforated reinforcing member was fixed to the wall surface of the continuous wall to which the water guide nozzle was to be attached via a sealing material. Then, the hole of the fixed perforated reinforcing member was similarly filled with a sealing material, and an intermediate pipe with a flange was inserted into the hole filled with the sealing material to be fixed to the wall surface.

Further, an insertion hole of a water guide nozzle that penetrates the wall of the underground continuous wall through the inside of the flanged intermediate pipe fixed to the wall surface is inserted, and a water guide thin tube of the water transfer nozzle is inserted into the drilled insertion hole. The nozzle was fixed to the continuous underground wall with a water seal structure. A water level tube made of a transparent material was connected and connected to the fixed water guide nozzle in such a manner that the water level tube was erected vertically along the wall surface of the continuous wall.

(Operation)

Since the present invention is configured as described above,
The water level of the groundwater at the back of the underground continuous wall can be known by detecting the water level of the water level pipe.

When the water level can be detected, the water pressure acting on the back of the underground continuous wall can be measured. Further, based on the measured data, it is possible to obtain information such as design of the underground continuous wall and stress analysis as well as safety management of the construction.

〔Example〕

Further, the configuration and operation of the present invention will be specifically described based on embodiments shown in the drawings.

First, FIG. 1 is a side view showing a state in which a measuring device of the present invention is attached as a means for measuring back water pressure to an earth retaining work composed of a column-type underground continuous wall. That is, it is a principle diagram of water pressure measurement. In this figure, 1 is a continuous wall, and 2 is a water supply nozzle for groundwater attached to a wall near the root 3.
Reference numeral 4 denotes a water level pipe connected to the water guide nozzle 2 and is vertically provided along the wall surface of the continuous wall 1.

Since the water level is set as described above, the groundwater level can be necessarily confirmed by detecting the water level of the water level pipe 4.

As described above, since the water level tube 4 is made of a transparent material, the water level in the water level tube 4 can be read even in the case of turbid water, and the groundwater level can be easily detected. Of course, the water level tube 4 may be scaled in advance to provide a scaled water level tube 4.

FIGS. 2 to 10 show a method of mounting the measuring instrument having the above-described configuration in the order of steps.

First, FIG. 2 is a cross-sectional plan view of a column-type underground continuous wall filled with soil cement 1b using an I-type steel as the stress material 1a. FIG. 3 is a partial plan view thereof. In mounting the measuring instrument, the mounting position of the wall surface of the continuous wall 1, that is, the wall surface close to the root bottom 3 is first cleaned. Specifically, the surface of the soil cement 1b constituting the wall 1c and the flange surface of the stress material 1a are cleaned with a wire brush or the like. Then, a sealing material 5 is applied to the cleaning portion.

Next, as shown in FIG. 4, a perforated reinforcing member 6 is applied to the applied sealing material 5 and fixed using welding means. FIG. 5 is a side view showing the fixed state. When the fixing process is completed, an attachment hole 8 for fixing a later-described flanged intermediate pipe 7 is formed in a portion corresponding to the hole 6a of the fixed perforated reinforcing member 6, that is, a soil cement portion 1b of the wall 1c. .

FIG. 6 shows a state in which the hole 8 is being drilled. The power tool 9 is used as a tool.

Next, the sealing material 5 is filled in the mounting hole 8 as shown in FIG.

When the filling operation of the sealing material 5 is completed, the intermediate pipe with flange 7 is inserted and set in the mounting hole 8 as shown in FIG. Then, the flange portion 7a is fixed to the reinforcing member 6 already fixed to the wall surface by using welding means. In this case, it is preferable to take a certain curing period in order to strengthen the connection between the flanged intermediate pipe 7 and the wall 1c. That is, it is preferable to wait for the sealing material 5 to harden.

When the mounting operation of the flanged intermediate pipe 7 is completed, the insertion hole 10 for inserting the water guiding thin tube 2a of the water guiding nozzle 2 which passes through the inside of the flanged intermediate pipe 7 and penetrates the wall 1c of the continuous wall 1 is formed. Perforate. FIG.
A state in which the drilling operation is being performed using the electric tool 9 shown in the figure is shown.

When this drilling operation is performed, groundwater flows out through the insertion hole 10, but the water guide nozzle 2 is attached as shown in FIG. As shown in the drawing, the water guide nozzle 2 is connected to a water guide tube 2a and a riser tube 2b from the water guide tube 2a, and cocks 2c and 2c are attached to ends of the riser tube 2b and the water guide tube 2a, respectively. . As the water guide thin tube 2a used in the embodiment shown in the drawings, a tube composed of a metal pipe having an outer diameter of 13 mm was used.

Then, this water guide thin tube 2a is inserted into the perforated insertion hole 10, and the leading end opening (left side in the drawing) of the water guide thin tube 2a is inserted.
Is set so as to penetrate the wall 1c of the continuous wall 1 and communicate with the groundwater side.

In addition, in the embodiment, as the setting procedure,
2a, a mounting plug 12 having a tightening bolt head 11 as shown in FIG. 10 is provided. It is set with a water seal structure. Reference numeral 12a denotes a rubber packing for sealing provided on the back surface of the mounting plug 12. When the mounting of the water guide nozzle 2 on the wall surface is completed in the above manner, the water level pipe 4 made of a transparent material is connected to the riser pipe 2b side of the water guide nozzle 2. That is, the lower end of the water level pipe 4 is inserted and connected to the pipe end of the riser pipe 2b so that the water level pipe 4 communicates with the water introduction nozzle 2. At that time, the water level tube 4 itself is naturally set up vertically along the wall surface.

 The above is the mounting method of the measuring device according to the present invention.

Note that a scale for measuring the water level height may be engraved on the water level pipe 4 in advance, or the water level confirmed by the water level pipe 4 from GL may be separately measured on a scale. In addition, when the water level pipe 4 is connected to the water introduction nozzle 2 side, the turbid groundwater may enter the water level pipe 4 and cause inconvenience in checking the water level. Therefore, the water level pipe 4 is connected to the water introduction nozzle 2 side. It is convenient to fill the water level pipe 4 with tap water beforehand.

In this embodiment, a high-strength cement mortar was used as the sealing material 5 used to make the mounting structure of the water guide nozzle 4 a complete water sealing structure. However, as long as it has a sealing function, it is not limited to the high-strength cement mortar, and may be a polymer sealing material such as paraffin / urethane resin. In short, it is sufficient that the mounting work is easy and the watertightness is high.

〔The invention's effect〕

The use of the back water pressure measuring device according to the present invention is useful for improving the following underground continuous wall construction technology.

(1) The water pressure acting on the back of the underground continuous wall can be easily calculated. As a result, if a structural analysis is performed in combination with measurement data from a strain gauge or an inclinometer, it becomes possible to calculate the internal stress of the continuous wall, for example, bending stress or shear stress, which is necessary for calculating the structural strength of the continuous wall itself. Data can be obtained. It is particularly effective when the continuous wall is constructed as a so-called structural wall.

In addition, the construction as a measuring instrument is simple, and as explained based on the construction procedure, its installation work is simple, it can be performed manually, and it has a completely watertight structure, so it has a high level of specialized technical knowledge , That is, the back water pressure can be measured with high accuracy even by the on-site worker. As a result, it becomes possible to accumulate various design data related to the construction of the underground continuous wall, which can contribute to the improvement of technology.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention, and FIG. 1 is a side view showing a state in which a measuring device for measuring back water pressure on a retaining wall composed of a column-type underground continuous wall is attached. FIG. 2 to FIG. 10 show the procedure for mounting the measuring device in the order of steps, FIG. 2 is a partial cross-sectional plan view of the continuous wall showing a state where a sealing material is applied to the side surface of the continuous wall, and FIG. Fig. 2 is a front view of Fig. 2, Fig. 4 is a front view showing a state in which a reinforcing member is fixed to a wall surface coated with a sealing material, Fig. 5 is a side view of Fig. 4, and Fig. 6 is an intermediate pipe with a flange on the wall surface. FIG. 7 is a side view showing a state in which a sealing material is being filled in a perforated portion, and FIG. 8 is a side view showing a state in which an intermediate pipe with a flange is mounted. ,
Fig. 9 is a side view showing a state in which an insertion hole for attachment is drilled through a pipe of an intermediate pipe with a flange to attach a water guide nozzle, and Fig. 10 is a side view showing an attached state of the water guide nozzle. 1 ... continuous wall, 1a ... stress member 1b ... soil cement part 1c ... wall, 2 ... water guide nozzle 2a ... water guide thin tube, 2b ... riser 2c ... cock, 3 ... root cutting bottom 4 ... water level pipe, 5 ... sealing material 6 ... perforated reinforcing member, 6a ... hole 7 ... intermediate pipe with flange 7a ... flange, 8 ... mounting hole 9 ... electric power tool, 10 ... … Insertion hole 11… Tightening bolt head 12… Installation plug, 12a …… Packing

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-131111 (JP, A) Jikken 54-10722 (JP, Y1) (58) Fields investigated (Int. Cl. ⁶ , DB name) E02D 5/02-5/20 G01L 7/00

Claims (2)

(57) [Claims] 1. An underground water feed nozzle and a water level pipe, wherein the water feed nozzle is attached to a wall surface adjacent to a root bottom of an underground continuous wall by penetrating the wall body, and the water level pipe is The underground continuous wall back surface water pressure measuring device, comprising a transparent material, a lower end of which is connected to and connected to the water guide nozzle, and is vertically erected along a wall surface of the continuous wall. 2. A step of fixing a perforated reinforcing member to a wall surface adjacent to the root bottom of the underground continuous wall via a sealing material, and a wall corresponding to a hole of the fixed perforated reinforcing member. A hole for filling the sealing material, filling the hole with the sealing material, and then inserting and fixing the intermediate pipe with the flange, and passing the wall of the underground continuous wall through the pipe of the intermediate pipe with the flange. A step of piercing an insertion hole for inserting a water guide thin tube in a penetrating water guide nozzle, and a step of inserting a water guide thin tube in the water guide nozzle into the pierced insertion hole, and fixing the water guide nozzle to a continuous underground wall surface with a water seal structure, Connecting the lower end of the water level pipe to the water guide nozzle.