Device and method for continuously measuring mud specific gravity

Abstract

The present invention discloses a device and method for continuously measuring mud specific gravity. During underwater concrete pouring operations such as bored piles and underground continuous walls, the device is placed into the mud at any depth within the pile hole or underground continuous wall trench. The pressure plates at the upper and lower ends of the device will produce a certain displacement relative to the sedimentation cylinder due to the different pressure differences, thereby changing the resistance of the circuit structure inside the device. The resistance has a strict conversion relationship with the mud specific gravity. By measuring the change in resistance, the mud specific gravity of the location where the device is located can be converted. Not only can the specific gravity of the wall retaining mud at any depth and any location within the pile hole or underground continuous wall trench be directly measured, but the operation is simple and fast, and no sampling is required, thus providing fast and accurate construction parameters for subsequent construction processes. The present invention solves the problem that existing mud specific gravity measuring devices have a relatively cumbersome sampling and measurement process when measuring mud specific gravity.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and in particular to a device and method for continuously measuring mud specific gravity. Background Art

[0002] During the construction of building foundations, many operations require the use of density measuring devices to determine the specific gravity of slurry (or cement slurry). For example, during bored pile drilling and hole cleaning, or underground diaphragm wall trenching and trench cleaning, the specific gravity of the slurry in the pile hole or trench must be measured. Based on the measurement results, relevant construction parameters such as the drilling speed of the drill, the trenching speed of the trencher, and the concrete pouring time must be adjusted to ensure that the construction process meets regulatory requirements.

[0003] Existing mud gravity measurement devices often require taking a mud sample beforehand, then placing the sample into the device for measurement. This sampling and measurement process is cumbersome, and each measurement can only determine the mud gravity at a specific sampling point, not continuously measuring the mud gravity within a specific depth range.

[0004] In addition, for mud at a relatively deep depth, such as the bottom of bored pile holes or the bottom of underground continuous wall trench sections, when using existing mud density measuring devices for measurement, the accuracy of the measurement results is greatly affected by the sampling method.

[0005] The information disclosed in this background technology section is only intended to enhance understanding of the overall background of the invention and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the Invention

[0006] In order to overcome the defects of the existing technology, a device and method for continuously measuring mud gravity are provided to solve the problem that the sampling and measurement process of the existing mud gravity measuring device is relatively cumbersome when measuring mud gravity.

[0007] To achieve the above object, a device for continuously measuring mud density is provided, comprising:

[0008] A vertically arranged sedimentation cylinder, the sedimentation cylinder having two open ends, a pressure plate slidably provided in each of the two open ends, a support frame installed in the sedimentation cylinder, the support frame forming a guide hole arranged along the axial direction of the sedimentation cylinder, a connecting rod slidably provided in the guide hole, the connecting rod is fixedly connected between the pressure plates in the two open ends, the connecting rod is installed on the support frame through an elastic reset member, an elastic sealing film is installed on the outer side of the open end, and the elastic sealing film is pressed against the pressure plate;

[0009] A circuit structure includes a resistance wire, a conductive contact, a power supply, and an ammeter, wherein the resistance wire is mounted on the support frame and arranged along the axial direction of the settling cylinder, one end of the conductive contact is mounted on the connecting rod, the other end of the conductive contact is pressed against one end of the resistance wire, and the other end of the resistance wire is connected in series with the conductive contact, the power supply, and the current;

[0010] A controller for acquiring the current value collected by the ammeter and calculating the mud density based on the current value and a preset conversion formula is connected to the ammeter.

[0011] Furthermore, the support frame includes:

[0012] Two radial plates arranged opposite to each other, the radial plates being connected to two opposite inner walls of the settling cylinder, the radial plates being provided with the guide holes, the connecting rod being slidably arranged in the guide holes of the two radial plates;

[0013] The reinforcing rod is connected between the two radial plates.

[0014] Furthermore, the resistance wire is wound around the reinforcement rod and is spirally shaped.

[0015] Furthermore, the guide hole is coaxially arranged with the sedimentation cylinder.

[0016] Furthermore, the elastic return member is a coil spring, which is arranged between the two radial plates. The coil spring is sleeved on the connecting rod, one end of the coil spring is connected to a radial plate, and the other end of the coil spring is installed on the connecting rod.

[0017] Furthermore, a limiting pin is fixedly provided on the outside of the connecting rod, and the other end of the coil spring is connected to the limiting pin.

[0018] 7. The device for continuously measuring mud density according to claim 1, wherein the conductive sheet is a metal conductive sheet.

[0019] Furthermore, the length of the connecting rod is smaller than the length of the settling cylinder.

[0020] The present invention provides a method for measuring mud specific gravity using a device for continuously measuring mud specific gravity, comprising the following steps:

[0021] Lowering the settlement cylinder into the pile hole so that the settlement cylinder is vertically arranged in the pile hole and is located at a preset elevation in the pile hole;

[0022] The pressure plate at the open end of the settlement cylinder slides along the axial direction of the settlement cylinder under the action of the pressure difference of the mud at different heights in the pile hole, so that the conductive contact changes the position of pressing against the resistance wire, and the ammeter collects the current value;

[0023] The controller obtains the current value collected by the ammeter, and calculates the mud density at a preset elevation in the pile hole based on the current value and a preset conversion formula.

[0024] The beneficial effect of the present invention is that the device for continuously measuring the specific gravity of mud of the present invention is placed in the mud at any depth in the pile hole or underground continuous wall groove section during underwater concrete pouring operations such as bored piles and underground continuous walls. The pressure plates at the upper and lower ends of the device will produce a certain displacement relative to the sedimentation cylinder due to the different pressure differences, thereby changing the resistance of the circuit structure inside the device. The resistance has a strict conversion relationship with the specific gravity of mud. By measuring the change in resistance, the specific gravity of the mud at the location of the device can be converted. The device for continuously measuring the specific gravity of mud can not only directly measure the specific gravity of the wall protection mud at any depth and any location in the pile hole or underground continuous wall groove section, but also is simple and quick to operate, does not require sampling, and can provide fast and accurate construction parameters for subsequent construction processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0026] Figure 1 Schematic diagram of the structure of a device for continuously measuring mud density according to an embodiment of the present invention.

[0027] Figure 2 Schematic diagram of the circuit structure of an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0029] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0030] Reference Figure 1 and Figure 2 As shown, the present invention provides a device for continuously measuring mud density, including: a sedimentation cylinder 1, a circuit structure 2 and a controller.

[0031] Among them, the sedimentation cylinder adopts a metal sleeve, which, on the one hand, improves the service life of the sedimentation sleeve, and on the other hand, improves the sinking speed of the sedimentation cylinder.

[0032] The sedimentation cylinder 1 is arranged vertically and has two open ends, including an upper end and a lower end. Pressure plates 11 are slidably mounted in the two open ends of the sedimentation cylinder 1, respectively.

[0033] A support frame is installed in the sedimentation cylinder 1.

[0034] The support frame is formed with a guide hole extending along the axial direction of the sedimentation drum 1. A connecting rod 13 slides into the guide hole. The connecting rod 13 is fixedly connected between the pressure plates 11 at the two open ends. The connecting rod 13 is mounted to the support frame via an elastic return member 131. An elastic sealing membrane 14 is mounted on the outer side of the open end and presses against the pressure plates 11.

[0035] In this embodiment, the outer dimensions of the pressure plate are adapted to the outer dimensions and sizes of the open end of the sedimentation cylinder. The pressure plate slides in the open end along the axial direction of the sedimentation cylinder.

[0036] The elastic sealing membrane is a rubber membrane layer, which, on the one hand, prevents mud from entering the sedimentation cylinder through the inner wall between the pressure plate and the open end of the sedimentation cylinder; on the other hand, when the pressure plate slides under the pressure of the mud, it prevents the pressure plate from slipping off the sedimentation cylinder.

[0037] As a preferred embodiment, the length of the connecting rod 13 is smaller than the length of the sedimentation cylinder 1.

[0038] The circuit structure 2 includes a resistance wire 21 , a conductive contact 22 , a power supply 23 and an ammeter 24 .

[0039] Specifically, the resistance wire 21 is mounted on the support frame. The resistance wire 21 is arranged along the axial direction of the sedimentation cylinder 1. One end of the conductive contact 22 is mounted on the connecting rod 13. The other end of the conductive contact 22 presses against one end of the resistance wire 21. The other end of the resistance wire 21 is connected in series with the conductive contact 22, the power source 23, and the current.

[0040] To measure the specific gravity of the mud at a preset elevation within the pile hole, the sedimentation cylinder is lowered to the preset elevation, positioning the cylinder vertically. Because the mud at the upper and lower ports of the sedimentation cylinder exerts different pressures on the pressure plate, the two pressure plates slide along the axial direction of the sedimentation cylinder, causing the ammeter to collect a current value within the circuit structure. A controller is connected to ammeter 24. The controller is configured to obtain the current value collected by ammeter 24 and calculate the specific gravity of the mud at the preset elevation within the pile hole based on the current value and a preset conversion formula.

[0041] As a preferred embodiment, the support frame includes: two radial plates 121 and a reinforcement rod 122. The two radial plates 121 are arranged opposite to each other. The radial plates 121 are arranged along the radial direction of the sedimentation cylinder. The radial plates 121 are connected to the two opposite inner walls of the sedimentation cylinder 1.

[0042] Each radial plate 121 is provided with a guide hole. The connecting rod 13 is slidably mounted in the guide holes of the two radial plates 121. The guide holes are coaxially arranged with the settling cylinder 1. The guide holes are arranged in the middle of the radial plates.

[0043] The reinforcement rod 122 is connected between the two radial plates 121 .

[0044] In this embodiment, the resistance wire 21 is spiral-shaped and wound around the reinforcement rod.

[0045] As a preferred embodiment, the elastic reset member 131 is a coil spring. The coil spring is arranged between the two radial plates 121. The coil spring is sleeved on the connecting rod 13. One end of the coil spring is connected to a radial plate 121. The other end of the coil spring is mounted on the connecting rod 13.

[0046] A limiting pin 132 is fixedly provided at the middle portion of the outer portion of the connecting rod 13 . The other end of the coil spring is connected to the limiting pin 132 .

[0047] In this embodiment, the conductive sheet is a metal conductive sheet. Except for the circuit structure, the rest of the components are insulators to avoid affecting the current value of the circuit structure.

[0048] The present invention provides a method for measuring mud specific gravity using a device for continuously measuring mud specific gravity, comprising the following steps:

[0049] S1: Lower the settlement cylinder 1 into the pile hole so that the settlement cylinder 1 is vertically arranged in the pile hole and is located at a preset elevation in the pile hole.

[0050] S2: The pressure plate 11 at the open end of the sedimentation cylinder 1 slides along the axial direction of the sedimentation cylinder 1 under the action of the pressure difference of the mud at different heights in the pile hole, so that the conductive contact 22 changes the position of pressing against the resistance wire 21, and the ammeter 24 collects the current value.

[0051] S3: The controller obtains the current value collected by the ammeter 24, and calculates the mud density at a preset elevation in the pile hole based on the current value and a preset conversion formula.

[0052] The device for continuously measuring the specific gravity of mud of the present invention is placed into the mud at any depth in the pile hole or underground continuous wall groove section during underwater concrete pouring operations such as bored piles and underground continuous walls. The pressure plates at the upper and lower ends of the device will produce a certain displacement relative to the sedimentation cylinder due to the different pressure differences, thereby causing the resistance of the circuit structure inside the device to change. The resistance has a strict conversion relationship with the specific gravity of the mud. By measuring the change in resistance, the specific gravity of the mud at the location where the device is located can be converted. The device for continuously measuring the specific gravity of mud can not only directly measure the specific gravity of the wall protection mud at any depth and any location in the pile hole or underground continuous wall groove section, but also is simple and quick to operate, does not require sampling, and can provide fast and accurate construction parameters for subsequent construction processes.

[0053] In this embodiment, the conductive sheet and the stop pin are integrally formed and serve as a conductor. The coil spring is a metal spring. One end of the coil spring and the resistance wire are connected to the sinker via wires and connected to a power source and an ammeter to form a circuit structure.

[0054] When in use, first suspend the sedimentation tube vertically in the air, then connect the positive and negative electrodes of the power supply and ammeter to the two wires extending from the interior of the sedimentation tube (the wire connected to one end of the resistance wire and the coil spring), and measure and read the current I0 passing through the device. Assuming the power supply voltage is U0, based on the measured current I0, Ohm's law can be used to calculate the internal resistance of the device when suspended in the air:

[0055]

[0056] Specifically, the device is then vertically suspended in the mud liquid to be tested at a certain depth in the pile hole or underground continuous wall trench section. The power supply and ammeter are again used to measure the current I passing through the device, and the internal resistance of the device when suspended in the mud is calculated as:

[0057]

[0058] The areas of the pressure plate in the upper port and the pressure plate in the lower port of the sedimentation cylinder are both A.

[0059] The pressure intensity generated by the mud on the upper pressure plate is P1.

[0060] The mud pressure intensity generated by the mud on the lower pressure plate is P2.

[0061] The pressure difference generated by the mud on the two pressure plates is F=A·(P2-P1), and this difference is the buoyancy exerted on the internal cavity between the two pressure plates of the device.

[0062] The spring constant of the coil spring is k. According to Hooke's law of elasticity, when the internal cavity of the device is subjected to the buoyancy F of the mud, the upper and lower pressure plates, together with the pressure plate connecting rods and the metal conductive sheet, produce an upward displacement relative to the sedimentation cylinder:

[0063]

[0064] Specifically, assuming that the resistance adjustment coefficient of the sliding-wire rheostat composed of the reinforcement rod, the resistance wire, and the conductive sheet is C, then the increase in resistance inside the device compared to when it is suspended in the air is:

[0065] ΔR=R1-R0=C·ΔS.

[0066] Specifically, according to the above relationship, the conversion relationship between the buoyancy F and the resistance difference between the two measurements can be calculated as follows:

[0067]

[0068] Specifically, assuming that the distance between the upper surface of the upper pressure sensor 2 and the lower surface of the lower pressure sensor 3 is Δh, the volume of the cavity between the upper pressure sensor 2 and the lower pressure sensor 3 is V = A·Δh. Based on Archimedes' buoyancy principle, the density of the mud can be further calculated as:

[0069]

[0070] Specifically, the elastic coefficient k of the coil spring, the internal initial resistance of the device when it is vertically suspended in the air The pressure plate area A, the resistance adjustment coefficient C of the sliding line rheostat, the distance Δh between the upper surface of the upper pressure plate and the lower surface of the lower pressure plate, and the power supply (13) voltage U0 are all constants. The mud density ρ is inversely correlated with the current I, and the correlation coefficients are:

[0071]

[0072]

[0073] Specifically, to simplify the measurement process, before use, the device is suspended vertically in the air and connected to the power supply and ammeter, and the current I0 is measured. At this time, the mud specific gravity ρ0 = 0; then the device is suspended vertically in clean water and connected to the power supply and ammeter, and the current I w , at this time the corresponding mud density ρ w ≈1.0.

[0074] Substitute the two sets of ρ and I data into A set of linear equations with two variables can be obtained, and the conversion coefficients k1 and k2 between current and mud density can be calculated.

[0075] Specifically, the device is suspended vertically in mud of any specific gravity and connected to a power supply and an ammeter, and the current I is measured. According to the conversion formula obtained above, The specific gravity of the measured mud can be quickly converted.

[0076] Specifically, if the insulated wire connected to the lower end of the resistance wire is connected to the upper end of the resistance wire, then according to the above derivation and measurement process, the conversion relationship between mud density ρ and current I can be obtained as follows:

[0077] ρ=k3·I+k4,

[0078] Similarly, the specific gravity of the measured mud can be easily calculated based on the current I.

[0079] Specifically, when the mud density is large or the device is relatively light and cannot sink into the mud liquid, a counterweight can be added to the bottom of the device, or the device shell can be fixed on a hard rod first and then sent into the mud liquid.

[0080] Specifically, since the device of the present invention can be suspended in the mud liquid at any depth of the pile hole or the underground continuous wall groove section, it is possible to conveniently draw a curve of the continuous change of the mud density with the depth of the pile hole or the underground continuous wall groove section, which can provide fast and accurate construction parameters for the subsequent construction process.

[0081] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention herein is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features having similar functions disclosed in this application.

Claims

1. A device for continuously measuring mud density, characterized in that: include: A vertically arranged sedimentation cylinder, the sedimentation cylinder having two open ends, a pressure plate slidably provided in each of the two open ends, a support frame installed in the sedimentation cylinder, the support frame forming a guide hole arranged along the axial direction of the sedimentation cylinder, a connecting rod slidably provided in the guide hole, the connecting rod is fixedly connected between the pressure plates in the two open ends, the connecting rod is installed on the support frame through an elastic reset member, an elastic sealing film is installed on the outer side of the open end, and the elastic sealing film is pressed against the pressure plate; A circuit structure includes a resistance wire, a conductive contact, a power supply, and an ammeter, wherein the resistance wire is mounted on the support frame and arranged along the axial direction of the settling cylinder, one end of the conductive contact is mounted on the connecting rod, the other end of the conductive contact is pressed against one end of the resistance wire, and the other end of the resistance wire is connected in series with the conductive contact, the power supply, and the current; a controller connected to the ammeter, for obtaining the current value collected by the ammeter and calculating the mud density based on the current value and a preset conversion formula; The support frame includes: two radial plates arranged opposite to each other, the radial plates connected to the two opposite inner walls of the settling cylinder, the radial plates having the guide holes, the connecting rods slidingly arranged in the guide holes of the two radial plates; a reinforcement rod connected between the two radial plates; The resistance wire is wound around the reinforcement rod and is in a spiral shape; The guide hole is coaxially arranged with the sedimentation cylinder; The elastic return member is a coil spring, which is arranged between the two radial plates. The coil spring is sleeved on the connecting rod. One end of the coil spring is connected to a radial plate, and the other end of the coil spring is installed on the connecting rod.

2. The device for continuously measuring mud density according to claim 1, characterized in that: A limiting pin is fixedly provided on the outside of the connecting rod, and the other end of the coil spring is connected to the limiting pin.

3. The device for continuously measuring mud density according to claim 1, characterized in that: The conductive contact piece is a metal conductive piece.

4. The device for continuously measuring mud density according to claim 1, characterized in that: The length of the connecting rod is smaller than the length of the settling tube.

5. A method for measuring mud specific gravity using the device for continuously measuring mud specific gravity according to any one of claims 1 to 4, characterized in that: The following steps are involved: Lowering the settlement cylinder into the pile hole so that the settlement cylinder is vertically arranged in the pile hole and is located at a preset elevation in the pile hole; The pressure plate at the open end of the settlement cylinder slides along the axial direction of the settlement cylinder under the action of the pressure difference of the mud at different heights in the pile hole, so that the conductive contact changes the position of pressing against the resistance wire, and the ammeter collects the current value; The controller obtains the current value collected by the ammeter, and calculates the mud density at a preset elevation in the pile hole based on the current value and a preset conversion formula.

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