CN109972672B

CN109972672B - Concrete conveying guide pipe position measuring device for underwater cast-in-place pile construction

Info

Publication number: CN109972672B
Application number: CN201910357570.9A
Authority: CN
Inventors: 刘国清; 杨旭东; 吴京驰; 肖嵩
Original assignee: Southwest Jiaotong University
Current assignee: Southwest Jiaotong University
Priority date: 2019-04-29
Filing date: 2019-04-29
Publication date: 2020-10-30
Anticipated expiration: 2039-04-29
Also published as: CN109972672A

Abstract

The invention discloses a concrete conveying guide pipe position measuring device for underwater cast-in-place pile construction, which comprises a sensing unit and a display control unit, wherein the sensing unit is used for sensing the position of a concrete conveying guide pipe; the sensing unit comprises a plurality of surface pressure sensing sensors, the surface pressure sensing sensors are arranged on a mounting frame at fixed intervals from bottom to top, the mounting frame is fixedly connected to more than two welding blocks through bolts, and the more than two welding blocks are welded to the outer wall above the discharge hole of the concrete conveying conduit from bottom to top; the plurality of surface pressure sensing sensors are connected in series and then connected to the display control unit. The invention has the advantages that in the operation process of the underwater concrete cast-in-place pile, on-site operators are effectively guided to finish the lowering and lifting operation of the concrete conveying guide pipe, thereby playing the roles of ensuring the quality and avoiding construction accidents.

Description

Concrete conveying guide pipe position measuring device for underwater cast-in-place pile construction

Technical Field

The invention relates to the technical field of concrete pouring construction, in particular to a concrete conveying guide pipe position measuring device for underwater cast-in-place pile construction.

Background

In the construction process of underwater concrete pile pouring, the concrete is poured by a concrete conveying conduit method, that is, a concrete mixture enters the bottom of the concrete (as a waterproof layer) poured in the initial stage through the lower opening of the concrete conveying conduit, and the newly poured concrete supports the concrete poured in the initial stage to rise and expand to the periphery. The concrete at the bottom of the pile poured firstly is gradually lifted to the pile head part by the subsequent concrete, so that the concrete at the pile head part of the underwater poured pile is always the part poured firstly. Under the influence of pile bottom sediment, wall protection slurry, hole wall shape, a steel reinforcement cage and pile length, slurry (slurry, mortar, soil and concrete mixed slurry) with certain thickness can be covered on a rising concrete top layer, in the construction process, the outlet of the concrete conveying conduit must be ensured not to be separated from the concrete layer, otherwise, the soil is mixed into the concrete, and a broken pile construction accident can be caused, so that in the current construction, the depth of the concrete surface must be measured every half an hour, and the total length of the sections of the concrete conveying conduit is calculated. Obtaining the outlet position of the concrete conveying conduit, and ensuring that the concrete conveying conduit is buried under the concrete for 2-6 m. The shallow pipe orifice is easy to be separated from concrete to form a broken pile. The pile is buried too deeply, the pressure is too high, fresh concrete cannot be removed, old concrete is easy to be initially set after too long time, and pile breakage can be caused as a result.

The casting engineering is very tight, and each link must be in place. At present, the depth of a concrete conveying guide pipe is measured by means of the whole-course height of a heavy hammer and other tools by a detector, the labor intensity is high, absolute reliable construction cannot be guaranteed, once a pile breaking accident is caused, digging, drilling and hanging are generally needed, and waste is very huge.

Disclosure of Invention

The invention aims to provide a concrete conveying conduit position measuring device for underwater cast-in-place pile construction.

The technical scheme for realizing the purpose of the invention is as follows:

a concrete conveying conduit position measuring device for underwater cast-in-place pile construction comprises a sensing unit and a display control unit; the sensing unit comprises a plurality of surface pressure sensing sensors, the surface pressure sensing sensors are arranged on a mounting frame at fixed intervals from bottom to top, the mounting frame is fixedly connected to more than two welding blocks through bolts, and the more than two welding blocks are welded to the outer wall above the discharge hole of the concrete conveying conduit from bottom to top; the plurality of surface pressure sensing sensors are sequentially connected in series and then connected to the display control unit.

Further, the surface pressure sensing sensor comprises a strain resistor for sensing pressure, and the strain resistor is also connected with a resistor with a fixed resistance in parallel.

Further, the number of the surface pressure sensing sensors is 5, and the fixed distance between the surface pressure sensing sensors and the mounting rack is 1 m.

The invention has the advantages that in the operation process of the underwater concrete cast-in-place pile, on-site operators are effectively guided to finish the lowering and lifting operation of the concrete conveying guide pipe, thereby playing the roles of ensuring the quality and avoiding construction accidents.

Drawings

FIG. 1 is a schematic diagram of the composition of the apparatus of the present invention.

Fig. 2 is a schematic diagram of a series-parallel connection of five surface pressure sensors in the sensing unit of the present invention.

Fig. 3 is a schematic perspective view of the sensing unit structure of the present invention.

Fig. 4 is a schematic diagram of the triggering of the surface pressure sensor in the sensing unit of the present invention.

FIG. 5 is a schematic diagram of a display control unit interface in accordance with an embodiment of the present invention.

Detailed Description

The invention relates to a concrete conveying conduit position measuring device for underwater cast-in-place pile construction, which is fixed at a proper position above a discharge port of a concrete conveying conduit for cast-in-place pile cavity cast-in-place pile construction, acquires pressure information of a fluid medium to determine the position range of an interface between concrete and a slurry layer in a cavity and is used for assisting in guiding the construction of an underwater cast-in-place pile.

As can be seen from fig. 1, the device is composed of a sensing unit 100 and a display control unit 200 in information connection with the sensing unit; the sensing unit 100 comprises five surface

pressure sensing sensors

111, 112, 113, 114 and 115, which are mounted on a mounting frame 102 of the sensing unit 100 at intervals of 1 meter, wherein the mounting frame 102 is fixed to a welding block 101 through a bolt connection, and the welding block 101 is fixed to the conveying conduit 1 through a welding method. The sensing unit 100 transmits the measured value to the display control unit 200 through the communication cable, thereby guiding the construction work of the cast-in-place pile.

As can be seen from fig. 2, the five surface

pressure sensing sensors

111, 112, 113, 114 and 115 are connected in series, and inside each individual surface pressure sensor, the strain resistors for sensing pressure are connected in parallel with a fixed resistance resistor having a resistance of about 1000 kilo-ohms. The strain resistor inside the surface pressure sensor is infinite under the condition that the surface of the sensor is not stressed, so that after the strain resistor is connected with a fixed resistance resistor in parallel, the output value of the parallel circuit shows the resistance value of the fixed resistor under the condition that the strain resistor is not stressed. The strain resistor inside the surface pressure sensor has a small value (0-100 kilo-ohm) under the condition that the surface of the sensor is stressed, and the output value of the parallel circuit is expressed as the resistance value of the strain resistor under the condition that the surface of the sensor is stressed. By utilizing the series-parallel combination mode, the information transmission can be completed only by two wires in the connecting cable, and the detection operation can be completed under the condition of 50 meters or even deeper underwater.

The sensing unit 100 and the display control unit 200 are coupled by a cable and a connector 207. The display control unit comprises a power supply module 201, a data analysis module 202, a display module 203, a communication module 204, an input interface 205 and an output interface 206. The display control unit 200 recognizes a position range of the concrete top surface at the guide pipe by analyzing the magnitude and the variation amount of the measured value, and guides the construction work. The interface of the display control unit is schematically shown in fig. 5.

When the device is used, the welding block 101 is fixed to a proper position of a guide pipe in a welding mode, then the sensing unit is fixed to the welding block 101 through the mounting frame 102, the five surface pressure sensors are fixed to the mounting frame 102 at intervals of 1 meter, the lowest surface pressure sensor is 2 meters away from the outlet position of the guide pipe, and the highest surface pressure sensor is 6 meters away from the outlet position of the guide pipe. The resistance value of the internal parallel resistor of the surface pressure sensor is 1000 kilo-ohms. The internal strain resistor of the surface pressure sensor is triggered when the stress exceeds 50 g, and the strain resistance value corresponding to the stress of 50 g to 2 kg is 150 kilo-ohms to 30 kilo-ohms.

In the pouring process, the concrete gradually rises, when the concrete reaches the lowest surface pressure sensor, the surface pressure sensor senses the lateral pressure of the concrete, so that the output value of the whole series circuit is influenced, the display control unit analyzes the output value to judge that the top surface of the concrete is positioned 2 meters away from the outlet of the guide pipe at the moment, the concrete continues to rise along with the lapse of time, before the next surface pressure sensor is not triggered, the output value of the series circuit cannot be greatly changed, the display control unit can judge that the top surface of the concrete is positioned within the range of 2-3 meters away from the outlet of the guide pipe, when the concrete rises to reach the second surface pressure sensor, the output value of the series circuit is greatly changed, the display control unit judges that the top surface of the concrete is positioned 3 meters away from the outlet of the guide pipe according to the above, and so on, the display control unit can judge that the concrete top surface is positioned within the range of 2-6 meters away from the outlet of And (maximum error of 1 meter). And in the concrete pouring process, if the display control unit judges that the top surface of the concrete is within 2-6 meters from the outlet position of the guide pipe, no alarm is given. If the distance is 2-3 meters or 5-6 meters, which indicates that the danger of leaving the construction safety area exists, the display control unit can trigger the early warning indicator lamp. If the detection condition of the safe area is broken away from the early warning range, the display control unit immediately triggers an alarm indicator lamp to guide constructors to adjust the position of the catheter in time.

As can be seen from fig. 4, the sensing units are placed at different positions in the concrete environment, respectively, for triggering the surface pressure sensors, and thus obtaining data, as shown in the following table:

the monitor is shown in fig. 5, and the interface display conditions are as follows:

description of the drawings: and if the actual force measurement value is not in the force measurement value range of the upper table, triggering the processing according to the two adjacent measuring ranges.

The invention can effectively guide field operators to finish the lowering and lifting operation of the concrete conveying guide pipe in the operation process of the underwater concrete cast-in-place pile, thereby playing the roles of ensuring the quality and avoiding construction accidents.

Claims

1. A concrete conveying guide pipe position measuring device for underwater cast-in-place pile construction is characterized by comprising a sensing unit (100) and a display control unit (200); the sensing unit (100) comprises a plurality of surface pressure sensing sensors, the surface pressure sensing sensors are arranged on a mounting frame (102) at fixed intervals from bottom to top, the mounting frame (102) is fixedly connected to more than two welding blocks (101) through bolts, and the more than two welding blocks (101) are welded to the outer wall above the discharge hole of the concrete conveying conduit (1) from bottom to top; the plurality of surface pressure sensing sensors are sequentially connected in series and then connected to the display control unit (200);

the surface pressure sensing sensor comprises a strain resistor for sensing pressure, the resistance value of the strain resistor is infinite under the condition that the surface of the sensor is not stressed, and the resistance value of the strain resistor is reduced under the condition that the surface of the sensor is stressed; the strain resistor is also connected with a resistor with a fixed resistance value in parallel; and the display control unit (200) determines the distance between the top surface of the concrete and the discharge hole of the concrete conveying conduit (1) according to the change of the total resistance value of the surface pressure sensing sensors connected in series.

2. The concrete pipe position measuring apparatus as claimed in claim 1, wherein said surface pressure-sensitive sensors are 5 in number and are installed at a fixed interval of 1 m on the mounting frame (102).