Method for measuring top surface height of cast-in-situ bored pile with empty section in pile hole

Abstract

The invention discloses a method for measuring the top surface height of cast-in-place concrete of a cast-in-situ bored pile with an empty section in a pile hole. The method comprises the steps that a pile foundation reinforcement cage is manufactured, pre-embedded sensors are installed at the bottom of the pile foundation reinforcement cage, the pre-embedded sensors are connected through data lines, and the data lines are fixedly arranged on longitudinal main reinforcements of the pile foundation reinforcement cage; the pile foundation reinforcement cage provided with the embedded sensor is hoisted into the pile hole through a hanging bar, and a data line extends to the ground where the pile hole is located to be connected with a signal receiver; in the process of pouring the concrete in the pile hole, the pressure value of the concrete in the pile hole is measured in real time through the pre-embedded sensor; and the height of the top surface of the concrete poured in the pile hole is calculated through the signal receiver according to a fluid pressure formula. The method has the advantages of convenient, fast and accurate estimation.

Description

Technical Field

[0001] The invention relates to the field of pile foundation construction, in particular to a method for measuring the height of the top surface of poured concrete of a bored pile with a hollow section in the pile hole. Background Art

[0002] During the concrete pouring process for bored cast-in-place piles, it's necessary to continuously measure changes in the top surface height of the pile concrete to monitor pile quality and control the pile top elevation. In particular, for bored cast-in-place piles with a hollow section within the pile hole, the top surface height of the poured concrete must be continuously measured to ensure the pile reaches the designed elevation. This creates a bored cast-in-place pile with a hollow section. A bored cast-in-place pile with a hollow section refers to a pile where the upper section is hollow and unconcreted, while the lower section is solid and concreted. Traditional measurement methods rely on manual measurement using a measuring rope, long steel bars, or bamboo poles. Because the top surface of the pile concrete is a mixture of concrete and retaining slurry, its thickness and hardness are subject to significant uncertainty. Traditional measurement methods rely entirely on the surveyor's feel and experience, resulting in significant errors. For bored cast-in-place piles with long hollow sections, the pile top elevation can exceed 10 meters from the pile hole, making accurate measurement of the concrete top surface even more challenging. In order to ensure the quality of the pile top concrete, the control of the pile top elevation is often conservative, and the thickness of the concrete and mud mixture is overestimated, resulting in waste of concrete materials, increasing the workload of chiseling out the subsequent over-pile concrete and safety hazards. Summary of the Invention

[0003] The purpose of the present invention is to provide a method for measuring the top surface height of cast-in-place concrete in a bored pile with a hollow section in the pile hole, so as to avoid the waste of concrete material caused by excessive concrete pouring and the difficulty in removing the pile head.

[0004] In order to solve the above technical problems, the present invention provides a method for measuring the height of the top surface of the poured concrete of a bored cast-in-place pile with a hollow section in the pile hole, comprising:

[0005] Make a pile foundation steel cage, install a pre-buried sensor at the bottom of the pile foundation steel cage, connect the pre-buried sensor via a data cable, and fix the data cable on the longitudinal main reinforcement of the pile foundation steel cage;

[0006] The pile foundation steel cage with embedded sensors installed is hoisted into the pile hole through the lifting rods, and the data line is extended to the ground where the pile hole is located to connect with the signal receiver;

[0007] During the pouring of concrete in the pile hole, the pressure value of the concrete in the pile hole is measured in real time through the embedded sensor;

[0008] The top height of the concrete poured in the pile hole is calculated by the signal receiver according to the fluid pressure formula (1):

[0009] h2= P / ρg (1);

[0010] Among them, h2 is the height of the top surface of the concrete poured in the pile hole, P is the pressure value of the concrete poured in the pile hole, ρ is the density of the concrete poured in the pile hole, and g is the acceleration of the concrete poured in the pile hole.

[0011] Furthermore, the present invention provides a method for measuring the height of the top surface of the cast-in-place concrete of a bored pile with a hollow section in the pile hole. When the pile foundation reinforcement cage is hoisted into the pile hole and a height h1 is reserved with the pile bottom, the value h2+h1 is used as the height value of the top surface of the cast-in-place concrete in the pile hole.

[0012] Furthermore, the present invention provides a method for measuring the height of the top surface of the cast-in-place concrete of a bored pile having a hollow section in the pile hole, wherein the data line is fixedly arranged on the suspension rod.

[0013] Furthermore, the present invention provides a method for measuring the height of the top surface of the cast-in-place concrete of a bored pile having a hollow section in the pile hole, wherein the signal receiver includes a microcontroller and a display connected thereto.

[0014] Furthermore, the present invention provides a method for measuring the top surface height of cast-in-place concrete in a bored pile having a hollow section in the pile hole, wherein the embedded sensor is a vibrating wire stress gauge, a fiber grating sensor, a strain sensor or a piezoelectric sensor.

[0015] Furthermore, the present invention provides a method for measuring the height of the top surface of the cast-in-place concrete of a bored pile having a hollow section in the pile hole, in which the concrete is cast through a conduit with a hopper.

[0016] Furthermore, the present invention provides a method for measuring the height of the top surface of concrete poured in a bored cast-in-place pile with a hollow section in the pile hole. Before pouring concrete in the pile hole, the mud pressure value in the pile hole is measured by a pre-buried sensor; during the process of pouring concrete in the pile hole, the mixed pressure value of the concrete and mud in the pile hole is measured in real time by the pre-buried sensor, and the difference between the mixed pressure value and the mud pressure value is calculated in real time by a signal receiver as the pressure value of the concrete poured in the pile hole.

[0017] Compared with the prior art, the present invention provides the following beneficial effects:

[0018] During the concrete pouring process, a pre-embedded sensor measures the concrete pressure in the pile hole in real time. A signal receiver calculates the height of the top surface of the concrete poured in the pile hole based on the fluid pressure formula. This allows the system to measure the height of the top surface of the concrete poured in the pile hole and stop grouting after the concrete reaches a predetermined elevation within the pile hole. This completes the pouring of bored piles with empty sections in the pile hole, avoiding waste of concrete material caused by excessive pouring and the difficulty of chiseling out the pile head due to excessive pouring. This reduces both pouring and pile head chiseling costs. Compared to traditional manual measurement methods using rods, this system offers the advantages of convenient, fast, and accurate estimation of the top surface height of the concrete poured in the pile hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of the pile foundation reinforcement cage and the embedded sensors, data cables, and hanger bars installed on it;

[0020] Figure 2 This is a structural diagram of the pile foundation reinforcement cage sunk into the pile hole through the hanger bars;

[0021] Figure 3 It is a schematic diagram of the structure of pouring concrete into the pile hole to replace the mud;

[0022] Figure 4 This is a block diagram of the signal receiver;

[0023] As shown in the figure:

[0024] 100, pile hole;

[0025] 200. Pile foundation reinforcement cage;

[0026] 301, embedded sensor, 302, data line, 303, signal receiver;

[0027] 400, sling tendons;

[0028] 500, mud;

[0029] 600, concrete, 601, interface;

[0030] 700. Catheter. DETAILED DESCRIPTION

[0031] The present invention will be described in detail below with reference to the accompanying drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are all in a very simplified form and are not accurately scaled, and are only used to facilitate and clearly illustrate the embodiments of the present invention.

[0032] Please refer to Figures 1 to 4The embodiment of the present invention provides a method for measuring the height of the top surface of the poured concrete of a bored pile having a hollow section in the pile hole, comprising:

[0033] Step S1: Make a pile foundation reinforcement cage 200, install pre-embedded sensors 301 such as a vibrating wire stress gauge, a fiber Bragg grating sensor, a strain sensor, and a piezoelectric sensor at the bottom of the pile foundation reinforcement cage 200, connect the pre-embedded sensors 301 through a data cable 302, and fix the data cable 302 on the longitudinal main reinforcement of the pile foundation reinforcement cage 200.

[0034] In step S2, the pile foundation reinforcement cage 200, equipped with the embedded sensor 301, is hoisted and lowered into the pile hole 100 via the suspension rod 400. The data cable 302 is extended to the ground level within the pile hole 100 and connected to the signal receiver 303. At this point, the pile hole 100 contains mud 500, which serves to protect the pile hole 100. The signal receiver 303 includes a microcontroller, such as a single-chip microcomputer, and a connected display, such as an LCD. To ensure the stability of the data cable 302 during the empty pile section, the data cable 302 can be fixed to the suspension rod 400.

[0035] Step S3: During the pouring of concrete in the pile hole 100, the pressure of the concrete in the pile hole 100 is measured in real time by the embedded sensor 301. The pressure of the mud is ignored. During the pouring of concrete in the pile hole 100, concrete (grouting) can be poured through a conduit 700 with a hopper, and the poured concrete can be used to displace the mud 500. Since the mud is a mud-water concrete material, the main component of which is water, the pressure of the mud can be ignored. To improve measurement accuracy, before pouring concrete in the pile hole 100, the pressure of the mud in the pile hole 100 is measured by the embedded sensor 301. During the pouring of concrete in the pile hole 100, the mixed pressure of the concrete and mud in the pile hole 100 is measured in real time by the embedded sensor 301. The difference between the mixed pressure and the mud pressure is calculated in real time by the signal receiver 303 as the pressure of the concrete poured in the pile hole 100. The pressure of the mud before and after the displacement is taken into account.

[0036] Step S4: The top height of the poured concrete in the pile hole 100 is calculated by the signal receiver 303 according to the fluid pressure formula (1):

[0037] h2= P / ρg (1);

[0038] Where h2 is the height of the top surface of the concrete poured in pile hole 100, P is the pressure of the concrete poured in pile hole 100, ρ is the density of the concrete poured in pile hole 100, and g is the acceleration of the concrete poured in pile hole 100. In formula (1), P, ρ, and g are all known parameters. Find h2.

[0039] The embodiment of the present invention provides a method for measuring the top height of the concrete poured into a bored cast-in-place pile with a hollow section in the pile hole. During the concrete pouring process in the pile hole 100, the pressure value of the concrete in the pile hole 100 is measured in real time by a pre-embedded sensor 301. The height of the top height of the concrete poured into the pile hole 100 is calculated by a signal receiver 303 according to a fluid pressure formula. The height of the top height of the concrete poured into the pile hole 100 is thus measured. The grouting is stopped after the concrete pouring reaches a predetermined elevation in the pile hole 100, thus completing the pouring construction of the bored cast-in-place pile with a hollow section in the pile hole 100. That is, the interface 601 is the designed elevation for the concrete pouring in the pile hole 100, and the upper section of the pile hole 100 is a hollow section. This avoids the waste of concrete materials caused by excessive pouring of concrete and the difficulty in chiseling out the pile head due to excessive pouring of concrete, thereby reducing the pouring cost and the cost of chiseling out the pile head. It should be noted that since the pressure values or partial pressure values of the slurry before and after displacement are ignored, the result of measuring the height of the top surface of the poured concrete in the pile hole 100 is an approximate result, not an exact result. However, it is sufficient to monitor the height of the top surface of the poured concrete in the pile hole 100 and control the grouting to stop after the concrete is poured at a predetermined elevation in the pile hole 100, thereby completing the pouring of bored cast-in-place piles with a void in the pile hole. Compared with the traditional manual measurement method of inserting a rod, measuring the height of the top surface of the poured concrete in the pile hole is convenient and fast, avoids the subjective judgment of the construction workers, and has the advantage of relatively accurate estimation.

[0040] Please refer to Figures 2 to 3 Since the pile foundation reinforcement cage 200 is sunk into the pile hole 100 with a predetermined distance, for example, a height of h1 meters is reserved, in order to calculate the accuracy of the measurement of the top surface height of the cast-in-place concrete of the bored cast-in-place pile, the embodiment of the present invention provides a method for measuring the top surface height of the cast-in-place concrete of a bored cast-in-place pile with a void in the pile hole. When the pile foundation reinforcement cage 200 is hoisted into the pile hole 100 with a height of h1 reserved from the pile bottom, the value of h2+h1 is used as the top surface height of the cast-in-place concrete in the pile hole 100.

[0041] The present invention is not limited to the specific embodiments described above. Obviously, the embodiments described above are only some embodiments of the embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention described, all other embodiments obtained by ordinary technicians in this field fall within the scope of protection of the present invention. Those skilled in the art can make other levels of modifications and changes to the present invention. In this way, if these modifications and changes of the present invention fall within the scope of the claims of the present invention, the present invention is also intended to include these changes and changes.

Claims

1. A method for measuring the top surface height of a bored pile with a hollow section in the pile hole, characterized in that: include: Make a pile foundation steel cage, install a pre-buried sensor at the bottom of the pile foundation steel cage, connect the pre-buried sensor via a data cable, and fix the data cable on the longitudinal main reinforcement of the pile foundation steel cage; The pile foundation steel cage with embedded sensors installed is hoisted into the pile hole through the lifting rods, and the data line is extended to the ground where the pile hole is located to connect with the signal receiver; During the pouring of concrete in the pile hole, the pressure value of the concrete in the pile hole is measured in real time through the embedded sensor; The top height of the concrete poured in the pile hole is calculated by the signal receiver according to the fluid pressure formula (1): h2= P / ρg (1); Among them, h2 is the height of the top surface of the concrete poured in the pile hole, P is the pressure value of the concrete poured in the pile hole, ρ is the density of the concrete poured in the pile hole, and g is the acceleration of the concrete poured in the pile hole.

2. The method for measuring the top surface height of a bored pile with a hollow section in the pile hole according to claim 1, wherein: When the pile foundation reinforcement cage is hoisted into the pile hole and a height h1 is reserved between the pile bottom, the value of h+h1 is used as the height of the top surface of the concrete poured in the pile hole.

3. The method for measuring the top surface height of a bored pile with a hollow section in the pile hole according to claim 1, wherein: Fix the data cable on the suspension rod.

4. The method for measuring the top surface height of a bored pile with a hollow section in the pile hole according to claim 1, wherein: The signal receiver includes a microcontroller and a display connected thereto.

5. The method for measuring the top surface height of a bored pile with a hollow section in the pile hole according to claim 1, wherein: The embedded sensor is a vibrating wire strain gauge, a fiber grating sensor, a strain sensor or a piezoelectric sensor.

6. The method for measuring the top surface height of a bored pile with a hollow section in the pile hole according to claim 1, characterized in that: Concrete is poured through a duct with a hopper.

7. The method for measuring the top surface height of a bored pile with a hollow section in the pile hole according to claim 1, characterized in that: Before pouring concrete in the pile hole, the mud pressure value in the pile hole is measured by the embedded sensor; during the process of pouring concrete in the pile hole, the mixed pressure value of the concrete and mud in the pile hole is measured in real time by the embedded sensor, and the difference between the mixed pressure value and the mud pressure value is calculated in real time by the signal receiver as the pressure value of pouring concrete in the pile hole.

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