Filler pouring depth confirmation device

Abstract

To provide a filler placement depth confirmation device capable of precisely confirming the depth of a filler to be filled between the steel pipe and the pile hole installed around the outer periphery of a cast-in-place steel pipe concrete pile.SOLUTION: A filler placement depth confirmation device 10 includes: a steel pipe 14 that is placed around the outer periphery of a cast-in-place steel pipe concrete pile; multiple heat contact points 18B that are arranged on the outer peripheral surface of the steel pipe 14 at intervals along the longitudinal direction of the steel pipe 14; and a temperature display part 20A that displays the temperature measured by the heat contact points 18B.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a device for checking the pouring depth of filler material. [Background technology]

[0002] One method used in cast-in-place steel pipe concrete pile construction is called the overflow filling method. In this method, a reinforcing bar cage with a steel pipe attached to the top is erected in the pile hole, and concrete is discharged from a tremie pipe inserted inside the reinforcing bar cage. As the concrete is discharged, the concrete level rises and overflows from the top of the steel pipe. The overflowing concrete falls into the stabilizer liquid present in the gap between the steel pipe and the pile hole (for example, a gap of about 50 to 100 mm), replacing the stabilizer liquid and filling the gap, which is then pushed up by the concrete.

[0003] Therefore, in the overflow filling method, even if concrete is filled inside the steel pipe during the concrete filling process, the level of the concrete filled in the gap between the steel pipe and the pile hole will be lower than the level inside the steel pipe, so it is necessary to check whether concrete has been filled in the gap between the steel pipe and the pile hole. As a method for measuring the pouring level of the filler, there are methods described in Patent Documents 1 to 5, for example. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6343864 [Patent Document 2] Patent No. 2907769 [Patent Document 3] Japanese Patent Application Publication No. 6-347306 [Patent Document 4] Japanese Patent Application Publication No. 9-059982 [Patent Document 5] Japanese Patent Application Publication No. 2019-015084 Summary of the Invention [Problem to be solved by the invention]

[0005] In Patent Documents 1 and 2, a measuring sinker is used to measure the drilling depth and the pouring level of a filler material such as concrete. When measuring the pouring level of filler using a measuring weight, the measuring weight is hung from the top of the filler, but the feel transmitted to the measurer's hand varies depending on the hardness, specific gravity, and viscosity of the filler, so the measured value is likely to vary.In addition, since the depth is determined by feel, the measured value will vary depending on the skill and experience of the measurer. Furthermore, when checking the placement of filler between the steel pipe and the pile hole of a cast-in-place concrete pile, it may not be possible to insert a measuring sinker into the gap.

[0006] In the anchor / grout top detection method of Patent Document 3, multiple thermocouples are attached at predetermined intervals in the depth direction to tension members such as guide bars and PC steel wires placed in anchor holes, and the position of the poured grout is detected by detecting the temperature difference between each thermocouple. However, it is not possible to detect the position of the concrete filled in the gap between the steel pipe installed on the periphery of a cast-in-place concrete pile and the pile hole.

[0007] In the underwater concrete pouring method of Patent Document 4, an optical fiber temperature sensor is placed on the tremie pipe used when pouring the concrete, or on a holding member placed parallel to it, and the boundary between the concrete and water is detected by the temperature difference between them. However, it is not possible to detect the position of the concrete filled in the gap between the steel pipe installed on the periphery of the cast-in-place concrete pile and the pile hole.

[0008] Furthermore, in the concrete filling confirmation method of Patent Document 5, an optical fiber sensor is attached to a reinforcing bar cage set into an underground hole, while maintaining a predetermined distance from the reinforcing bar cage via a connecting member, to confirm the concrete filling status, but it is not possible to detect the position of the concrete filled in the gap between the steel pipe installed on the periphery of the cast-in-place concrete pile and the pile hole.

[0009] In consideration of the above facts, the present invention aims to provide a pouring depth confirmation device that can accurately confirm the depth of the filler material filled between the steel pipe installed on the outer periphery of a cast-in-place steel pipe concrete pile and the pile hole. [Means for solving the problem]

[0010] The filler casting depth confirmation device described in claim 1 comprises a steel pipe provided on the outer periphery of a cast-in-place steel pipe concrete pile, a plurality of temperature measuring units arranged at intervals along the longitudinal direction of the steel pipe on the outer surface of the steel pipe, and a temperature display unit that displays the temperature measured by the temperature measuring units.

[0011] The filling material pouring depth confirmation device according to claim 1 can confirm the pouring depth of the filling material as follows. When constructing a cast-in-place concrete pile, a steel pipe with multiple temperature measurement devices on its periphery is inserted into the pile hole and filler material is poured into it. When the filler material fills the gap between the steel pipe and the pile hole wall, the temperature of the filled area and the unfilled area differs. By viewing the temperatures at the multiple locations where the temperature measurement devices are located on the temperature display, the depth of the filler material between the steel pipe and the pile hole can be accurately confirmed.

[0012] The invention described in claim 2 is the filling material pouring depth confirmation device described in claim 1, wherein the temperature measurement unit is a hot junction of a thermocouple.

[0013] In the device for checking the filling material pouring depth described in claim 2, the temperature can be detected at the hot junction of the thermocouple. Thermocouples are easier to bend and handle than, for example, optical fibers.

[0014] The invention described in claim 3 is the filling material pouring depth confirmation device described in claim 1 or claim 2, wherein a heat insulating material is provided between the temperature measuring unit and the steel pipe.

[0015] In the filler casting depth confirmation device described in claim 3, by providing insulation between the temperature measurement unit and the steel pipe, the temperature of the temperature measurement object, such as the filler, can be accurately measured without being affected by the temperature of the steel pipe. [Effects of the Invention]

[0016] As described above, the filler casting depth confirmation device of the present invention has the excellent effect of being able to accurately confirm the depth of the filler that is filled between the steel pipe installed on the outer periphery of the cast-in-place steel pipe concrete pile and the pile hole. [Brief explanation of the drawings]

[0017] [Figure 1] A side view showing the position of the hot contact point of a pouring depth confirmation device according to one embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view of a steel pipe showing the vicinity of an end of a sheathed thermocouple. [Figure 3] FIG. 10 is a vertical cross-sectional view of a pile hole showing the position of the top of the concrete being measured with a pouring depth confirmation device. [Figure 4] 1 is a graph showing temperature changes. DETAILED DESCRIPTION OF THE INVENTION

[0018] A pouring depth confirmation device 10 according to one embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG. Figure 1 shows a cross-sectional view of the ground G during construction of a cast-in-place concrete pile. As shown in Figure 1, a reinforcing bar cage 16 with a steel pipe 14 attached to the top, which will become the head of the cast-in-place concrete pile, is erected inside a pile hole 12 formed in the ground G. A surface casing 17 is fitted into the opening of the pile hole 12.

[0019] An anchoring bar 16A is erected at the upper end of the steel pipe 14 to connect it to a footing or the like (not shown).

[0020] As shown in Figure 2, a plurality of sheathed thermocouples 18, which form part of the thermometer of the casting depth confirmation device 10, are attached to the outer periphery of the steel pipe 14. The sheathed thermocouples 18 are thermocouple wires (not shown) covered with tubes 18A, and hot junctions 18B, which serve as temperature measurement parts and are provided at the tips of the thermocouple wires, are exposed from the ends of the tubes 18A.

[0021] A heat insulating material 22 is provided between the tip of the sheathed thermocouple 18 and the steel pipe 14 so that the hot junction 18B does not come into contact with the steel pipe 14. The heat insulating material 22 is fixed to the outer circumferential surface of the steel pipe 14 using tape, double-sided tape, adhesive, or the like. The heat insulating material 22 may be a non-water-absorbent heat insulating material, such as polystyrene foam or polyurethane foam.

[0022] The sheathed thermocouple 18 is equipped with a temperature display unit 20A that displays the temperature, and is connected to a measuring device main body 20 that has a data logger function for temperature management. In this embodiment, the sheathed thermocouple 18 and the measuring device main body 20 form a thermometer 24.

[0023] As shown in FIG. 1, in this embodiment, six temperature measurement points L1 to L6 are provided at equal intervals (for example, at 2 m intervals) in a predetermined depth direction (axial direction of the steel pipe 14) of the steel pipe 14.

[0024] At the top temperature measurement point L6, the fifth temperature measurement point L5 from the bottom, and the second temperature measurement point L2, four hot junctions (temperature measurement junctions) 18B are arranged at equal intervals around the circumference in one cross section, and at the bottom temperature measurement point L1, the third temperature measurement point L3 from the bottom, and the fourth temperature measurement point L4, one hot junction 18B is arranged in one cross section. For this reason, in this embodiment, 15 sheathed thermocouples 18 are connected to the measuring device main body 20.

[0025] The uppermost temperature measurement point L1 is located at the upper end of the steel pipe 14.

[0026] 1 and 2, spacers 26 are provided at a plurality of locations in the circumferential and axial directions on the outer periphery of the steel pipe 14 so as to maintain a predetermined distance between the outer periphery of the steel pipe 14 and the inner periphery of the pile hole 12. The hot junction 18B of the sheathed thermocouple 18 is located radially inward of the steel pipe 14 relative to the spacers 26 so that the hot junction 18B does not come into contact with the inner periphery of the pile hole 12.

[0027] (Action, effect) Next, an example of use of the pouring depth confirmation device 10 of this embodiment will be described. Examples of methods for filling the outer periphery of the steel pipe of a cast-in-place steel pipe concrete pile include the overflow filling method and the grout filling method. Below, we will explain how to check the depth of concrete pouring using the overflow filling method.

[0028] After erecting the reinforcing bar cage 16 and steel pipe 14 in the pile hole 12, pouring of the concrete 32 begins once the measured temperature at each temperature measurement point (L1 to L6) has stabilized. Here, "stable measured temperature" means that the measured temperature has stabilized at a temperature lower than the temperature of the concrete 32 measured in advance.

[0029] Figure 3 shows the state in which the tip of a tremie pipe 30 is placed in a steel pipe 14 placed inside a pile hole 12 filled with a stabilizing liquid (bentonite, etc.) 28, and concrete 32 is being poured. In the figure, reference numeral 34 denotes a vibrator.

[0030] Concrete 32 is discharged from the tip of the tremie pipe 30, and as the concrete 32 rises inside the steel pipe 14 and overflows from the upper end of the steel pipe 14, the overflowing concrete 32 falls between the steel pipe 14 and the pile hole 12.

[0031] As the concrete 32 spilling out from the upper end of the steel pipe 14 falls into the gap between the steel pipe 14 and the pile hole 12, the level of the concrete 32 in the gap rises. Here, when the top of the rising concrete 32 comes into contact with the hot contact 18B located at the lowest temperature measurement point L1, the temperature measured at the hot contact 18B rises, and the worker can confirm by looking at the temperature display unit 20A that the concrete 32 has been filled up to the lowest temperature measurement point L1.

[0032] Similarly, when concrete 32 comes into contact with the hot contact 18B at each temperature measurement point, the measured temperature increases, making it possible to accurately confirm to what depth concrete 32 has been filled in the gap between the steel pipe 14 and the pile hole 12. Therefore, if the temperature measured at the hot junction 18B located at the upper end of the steel pipe 14 increases, it means that the concrete 32 has been poured up to the upper end of the steel pipe 14. This makes it possible to accurately confirm that the concrete 32 has been poured up to the upper end of the steel pipe 14.

[0033] An example of a graph showing the temperature change measured at each hot junction 18B is shown in Figure 4. From this graph, it can be seen that the concrete 32 rises in the gap between the steel pipe 14 and the pile hole 12 as time passes.

[0034] In this embodiment, the explanation is given assuming that the temperature of the concrete 32 is higher than that of the stabilizing solution 28, but it is also possible that the temperature of the concrete 32 is lower than that of the stabilizing solution 28. In such a case, it is understood that the portion of the hot junction 18B where the temperature change (here, the temperature drop) is measured is the boundary between the concrete 32 and the stabilizing solution 28, that is, that the concrete 32 has been poured up to the position of the hot junction 18B. The temperatures of the stabilizing solution 28 and the concrete 32 are measured in advance before pouring the concrete 32.

[0035] In this embodiment, the overflow filling method has been described, but the casting depth confirmation device 10 of this embodiment can be applied to construction methods other than the overflow filling method when constructing cast-in-place concrete piles using steel pipes, and can also be applied to the grout filling method.

[0036] [Other embodiments] The above describes an embodiment of the present invention, but the present invention is not limited to the above, and it goes without saying that the present invention can be implemented in various modified forms within the scope of the gist of the present invention.

[0037] In the above embodiment, an insulating material 22 is provided between the sheathed thermocouple 18 and the steel pipe 14 so that the hot junction 18B does not come into contact with the steel pipe 14. However, the tip portion of the sheathed thermocouple 18 may be held away from the steel pipe 14 by a support member or the like attached to the steel pipe 14 so that the hot junction 18B does not come into contact with the steel pipe 14.

[0038] In the above embodiment, the temperature is measured using a thermocouple, but the present invention is not limited to this, and other types of thermometers such as an optical fiber temperature sensor or a thermistor can also be used.

[0039] When using these thermometers, it is also preferable to provide a heat insulating material 22 between the temperature measuring part and the steel pipe 14 so that the temperature measuring part does not come into contact with the outer surface of the steel pipe 14. [Explanation of symbols]

[0040] 10. Pouring depth confirmation device 14 Steel pipe 18B Hot junction (temperature measurement part) 20A temperature display section 24 Thermometer 32 Concrete (filler)

Claims

1. a steel pipe provided on the outer periphery of the cast-in-place steel pipe concrete pile; a plurality of temperature measuring units arranged at intervals along the longitudinal direction of the steel pipe on the outer peripheral surface of the steel pipe; a temperature display unit that displays the temperature measured by the temperature measurement unit; having A device for checking the depth of filling material pouring.

2. The temperature measurement unit is a hot junction of a thermocouple. The filling material pouring depth confirmation device according to claim 1.

3. A heat insulating material is provided between the temperature measuring unit and the steel pipe. The filling material pouring depth confirmation device according to claim 1 or 2.

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