Device and method for measuring and evaluating quality of slope soil-rock contact surface

Abstract

The invention belongs to the technical field of geotechnical engineering and slope engineering, and discloses a device and method for measuring and evaluating the quality of a slope soil-rock contact surface, the device comprises a fixing device, a detection device and a data acquisition and analysis device, the fixing device comprises a base, a transverse connecting plate and a rotary joint; the detection device comprises an adapter, a resistivity probe, an ultrasonic transducer hinged to the transverse connecting plate and a shearing force measuring head connected with the transverse connecting plate through a sliding block and a telescopic rod. The data acquisition and analysis device comprises a processor; a connecting rod, a rotating joint, a connecting rod and a rotating joint are sequentially connected from the adapter to the transverse connecting plate; and the processor is in wired connection with the adapter, and is connected with the shearing force measuring head and the ultrasonic transducer through the wireless transmission device. According to the invention, on-site rapid measurement of slope soil-rock contact surface quality can be realized, multi-parameter synchronous acquisition is provided, and mechanical properties, compactness, moisture distribution and erosion resistance of the soil-rock interface are comprehensively reflected.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geotechnical engineering and slope engineering, and particularly relates to a device and method for measuring and evaluating the quality of a soil-rock contact surface of a slope. BACKGROUND

[0002] In the practice of geotechnical engineering and ecological slope protection, the bonding quality of the soil-rock interface directly affects the stability and protection effect of the slope. However, due to the existence of undulations, fissures and weathered layers on the rock surface, the overlying soil is prone to peeling, cracking and scouring under the action of hydraulic erosion, dry-wet cycle and freeze-thaw, thereby weakening the overall performance of the slope protection structure. Existing slope quality evaluation mainly focuses on soil mechanical parameters and rock mass structure characteristics, but lacks systematic measurement and quantitative evaluation methods for the quality of the soil-rock contact surface, resulting in insufficient risk assessment of slope engineering in long-term service. Therefore, it is of great engineering application value and popularization significance to develop a method and device that can accurately measure and evaluate the bonding quality of the soil-rock interface. SUMMARY

[0003] In order to solve the problem of lack of systematic measurement and quantitative evaluation methods for the quality of the soil-rock contact surface in the prior art, resulting in insufficient risk assessment of slope engineering in long-term service, the present application provides a device and method for measuring and evaluating the quality of the soil-rock contact surface of a slope. The device is portable and can quantitatively evaluate the bonding quality of the soil-rock contact surface of the slope, forming a quality index system with strong comparability, and is suitable for slope stability evaluation, ecological slope engineering quality detection and interface performance monitoring after the construction of the soil spraying and seeding technology.

[0004] The present application is realized by the following technical solutions: comprising a fixing device, a detection device and a data acquisition and analysis device, the fixing device comprising a base fixedly connected to the ground through fixing bolts, a transverse connecting plate and a rotary joint; the detection device comprising an adapter connected to the base, a resistivity probe connected to the adapter through an electric wire, an ultrasonic transducer hingedly connected to the transverse connecting plate, and a shear force measuring head connected to the transverse connecting plate through a sliding block and an extension rod; the data acquisition and analysis device comprising a processor; the adapter is sequentially connected to a connecting rod, a rotary joint, a connecting rod and a rotary joint; the sliding block is sleeved on the transverse connecting rod; the processor is connected to the adapter by wire and connected to the shear force measuring head and the ultrasonic transducer through a wireless transmission device.

[0005] As a further preferred, the resistivity probe is arranged in an array along the slope body.

[0006] As a further preferred, the extension rod is of a spiral type.

[0007] As a further preferred, the ultrasonic transducer has two, another ultrasonic transducer is horizontally arranged on the base near the side of the slope body.

[0008] The application also provides a use method of the device for measuring and evaluating the quality of the soil-rock interface of the slope.

[0009] S1, determining the soil-rock interface region of the slope to be measured, placing the base and fixing it with the fixing bolts;

[0010] S2, drilling the soil-rock interface of the slope to be measured, and installing the ultrasonic transducer into the hole of the soil-rock interface of the slope to be measured;

[0011] S3, inserting the resistivity probe into the surface of the soil-rock interface of the slope to be measured;

[0012] S4, moving the shear force measuring head to the surface of the soil-rock interface of the slope to be measured through the sliding block and the telescopic rod;

[0013] S5, the ultrasonic transducer, the resistivity probe and the shear force measuring head transmit the measured interface data to the processor through the wireless transmission device and the wire;

[0014] S6, the processor constructs the interface quality index based on the interface data, and grades the interface bonding quality.

[0015] As a further preferred, the formula for constructing the interface quality index in step S6 is as follows:

[0016] ;

[0017] In the formula, Iqi represents the interface quality index; V represents the measured ultrasonic wave speed; represents the measured shear strength; represents the measured resistivity; are weight coefficients; are the reference values of the ultrasonic wave speed, the shear strength and the resistivity, respectively.

[0018] As a further preferred, the drilling depth of the soil-rock interface of the slope to be measured in step S2 is 15 cm.

[0019] As a further preferred, the spacing of the resistivity probe in step S3 is not more than 10 cm.

[0020] As a further preferred, the number of measuring points of the shear force measuring head in step S4 is not less than 5.

[0021] Compared with the prior art, the application has the following beneficial effects:

[0022] 1.The present application can realize the on-site rapid measurement of the quality of the soil-rock contact surface of the slope, provide multi-parameter synchronous acquisition, and comprehensively reflect the mechanical properties, compactness, moisture distribution and erosion resistance of the soil-rock interface.

[0023] 2.The present application adopts ultrasonic transducers, resistivity probes and shear force measuring heads, which can accurately measure the compactness, moisture distribution and shear strength of the interface respectively.

[0024] 3.The present application can realize real-time data acquisition and transmission to the processing unit for comprehensive analysis, and finally output the comprehensive evaluation index of the soil-rock interface quality, thereby improving the scientificity and precision of the slope construction quality monitoring. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the device of the present application.

[0026] In the figure:

[0027] 1, base; 2, fixing bolt; 3, adapter; 4, rotary joint; 5, transverse connecting plate; 6, telescopic rod; 7, sliding block; 8, shear force measuring head; 9, ultrasonic transducer; 10, resistivity probe; 11, electric wire; 12, processor; 13, wireless transmission device. DETAILED DESCRIPTION

[0028] The advantages and characteristics of the present application will be illustrated and explained by the following non-limiting description of preferred embodiments, which are given by way of example only, with reference to the accompanying drawings.

[0029] As shown in Figure 1 , the present application provides a device for measuring and evaluating the quality of the soil-rock contact surface of the slope, which comprises a fixing device, a detection device and a data acquisition and analysis device.

[0030] The fixing device comprises a base 1, which is fixedly connected with the ground through a fixing bolt 2, preferably a horizontal ground. The fixing device further comprises a rotary joint 4 and a transverse connecting plate 5. The fixing device is used to fix the whole device at a suitable position, ensuring the accuracy of the measurement.

[0031] The detection device comprises an ultrasonic transducer 9, a resistivity probe 10, an adapter 3 and a shear force measuring head 8. The adapter 3 is fixedly connected with the base 1, and the adapter 3 is further connected with the resistivity probe 10 through an electric wire 11, and the resistivity probe 10 is arranged in an array along the slope body. The adapter 3 is sequentially connected with a connecting rod, a rotary joint 4, a connecting rod and a rotary joint 4, and the connecting rod and the rotary joint 4 are arranged to ensure the freedom of the device in each direction, so as to measure data at various angles. The transverse connecting plate 5 is horizontally arranged, and a sliding block 7 is sleeved on the transverse connecting plate 5, the sliding block 7 is fixedly connected with an extension rod 6, the extension rod 6 is vertically arranged, and the extension rod 6 is fixedly connected with the shear force measuring head 8 at an end away from the sliding block 7. In order to facilitate the control of the precision of the up-down movement of the shear force measuring head 8, the extension rod 6 can be arranged in a spiral form. The ultrasonic transducer 9 has two, one of which is arranged at an end of the transverse connecting plate 5 away from the rotary joint 4, and the ultrasonic transducer 9 is hinged with the transverse connecting plate 5; and the other ultrasonic transducer 9 is horizontally arranged on one side of the base 1 close to the slope body. The ultrasonic transducer 9 can detect the acoustic transmission characteristics of the soil-rock interface, and reflect the interface density, and the resistivity probe 10 is used to evaluate the water distribution and permeability of the interface. The shear force measuring head 8 is used to quickly measure the shear strength of the interface.

[0032] The data acquisition and analysis device comprises a wireless transmission device 13 and a processor 12, and can synchronously record parameters such as loading force, wave velocity, resistivity and shear strength. The processor 12 is connected with the adapter 3 through a wire, and the processor 12 is connected with the shear force measuring head 8 and the ultrasonic transducer 9 through the wireless transmission device 13. The processor 12 can display various indexes of the interface quality in real time, including parameters such as density, water distribution and shear strength.

[0033] The ultrasonic transducer 9 adopts an integrated design of emission and reception, can realize measurement between two points and calculate wave velocity and attenuation. The resistivity probe 10 is a multi-electrode array type, and can simultaneously test the resistivity distribution between a region. The extension rod 6 and the shear force measuring head 8 adopt a dynamic loading device, which can gradually increase the loading force and record the soil-rock interface reaction.

[0034] The application further provides a use method suitable for the device for measuring and evaluating the quality of a soil-rock contact surface of a slope.

[0035] Step 1, determining a soil-rock interface region to be measured, placing the base 1 and fixing the base 1 with the fixing bolt 2;

[0036] Step 2, drill holes on the top and bottom of the soil-rock interface of the slope to be measured, with a hole depth of 15 cm, install the ultrasonic transducer 9 on the base 1 into the hole at the bottom of the soil-rock interface of the slope to be measured, and install another ultrasonic transducer 9 into the hole at the top of the soil-rock interface of the slope to be measured through the rotary joint 4 and the transverse connecting plate 5;

[0037] Step 3, insert the resistivity probes 10 into the surface of the soil-rock interface of the slope to be measured, and the distance between each resistivity probe 10 is not more than 10 cm;

[0038] Step 4, move the shear force measuring head 8 to the surface of the soil-rock interface of the slope to be measured through the sliding block 7 and the telescopic rod 6; the position of the shear force measuring point in the same area is not less than 5, and the shear strength is the average value of each measuring point in the area.

[0039] Step 5, the ultrasonic transducer 9, the resistivity probe 10 and the shear force measuring head 8 transmit the measured interface data to the processor 12 through the wireless transmission device 13 and the wire 11;

[0040] Step 6, the processor 12 constructs the interface quality index based on the interface data, and grades the interface bonding quality, the formula is as follows:

[0041] ;

[0042] In the formula, V represents the measured ultrasonic wave speed, which is measured by the ultrasonic transducer 9; represents the measured shear strength, which is measured by the shear force measuring head 8; represents the measured resistivity, which is measured by the resistivity probe 10; are weight coefficients; are the reference values of the ultrasonic wave speed, the shear strength and the resistivity, respectively.

[0043] Embodiment

[0044] Next, combined with the ecological slope protection of a southern mountainous highway slope using the guest soil spray seeding technology, the slope height is about 15 meters, and the slope angle is about 45°. In order to ensure the long-term stability of the slope, it is necessary to detect and evaluate the bonding quality of the contact surface between the spray seeding layer and the bedrock, and the use method of the device for measuring and evaluating the quality of the soil-rock contact surface of the slope is adopted, and the steps are as follows:

[0045] Step 1, select a representative area in the lower part of the slope, clean the surface soil, ensure that the base 1 is placed stably and fixed with the fixing bolt 2.

[0046] Step 2, drill holes with a diameter of 5 cm and a depth of 15 cm on the top and bottom of the selected area, adjust the position of the ultrasonic transducer 9 through the rotary joint 4 and the transverse connecting plate 5, so that it is tightly attached to the hole wall, and ensure good coupling.

[0047] Step 3, insert the resistivity probe 10 into the slope surface at an interval of 10 cm, covering an area of about 1 m2. Connect to the adapter 3 through the wire 11, and prepare to test the resistivity distribution.

[0048] Step 4, control the position of the shear force measuring head 8 on the slope surface by moving the slider 7 and adjusting the telescopic rod 6. Set 5 measuring points in the same area, evenly distributed, and perform step-by-step loading test.

[0049] Step 5, start the device, and simultaneously collect the interface data measured by the ultrasonic transducer 9, resistivity probe 10, and shear force measuring head 8. The data is transmitted in real time to the processor 12 through the wireless transmission device 13.

[0050] Step 6, the processor 12 sorts the received data and calculates the average value of each parameter, V = 1650 m / s, τ = 95 kPa, ρ = 55 Ω·m. Substitute into the interface quality index formula:

[0051] The interface quality index Iqi is determined by the following formula:

[0052] ;

[0053] The reference values V0, τ0, and ρ0 are 1500 m / s, 90 kPa, and 60 Ω·m, respectively, and the weight coefficients α, β, and γ are 0.3, 0.5, and 0.2, respectively.

[0054] The slope soil-rock contact surface quality detection method is based on a large amount of measured data, establishes the interface quality index Iqi, and classifies the slope soil-rock interface bonding quality, as follows:

[0055] Table 1

[0056]

[0057] According to the classification standard in Table 1, Iqi = 1.076 belongs to level II (good), indicating that the slope soil-rock contact surface bonding quality is good, the interface density is high, the water distribution is uniform, the shear strength meets the stability requirements, and has strong anti-erosion ability. It is recommended to review regularly and focus on the water change area. It is recommended to strengthen the monitoring of the area with Iqi value close to the lower limit, and to conduct supplementary detection before the rainy season to prevent water accumulation from causing interface weakening.

[0058] In addition to the above embodiments, the present application can have other implementation manners, and any technical solutions formed by equivalent substitution or equivalent transformation shall fall within the protection scope of the present application.

Claims

1. A device for measuring and evaluating the quality of soil-rock contact surface of a slope, comprising a fixing device, a detecting device and a data acquisition and analysis device, characterized in that: The fixing device comprises a base (1) fixedly connected with the ground through a fixing bolt (2), a transverse connecting plate (5) and a rotary joint (4); the detecting device comprises an adapter (3) connected with the base (1), a resistivity probe (10) connected with the adapter (3) through an electric wire (11), an ultrasonic transducer (9) hingedly connected with the transverse connecting plate (5) and a shear force measuring head (8) connected with the transverse connecting plate (5) through a sliding block (7) and an extension rod (6); the data acquisition and analysis device comprises a processor (12); connecting rods, rotary joints (4) are sequentially connected from the adapter (3) to the transverse connecting plate (5); the sliding block (7) is sleeved on the transverse connecting rod (5); the processor (12) is wiredly connected with the adapter (3) and is connected with the shear force measuring head (8) and the ultrasonic transducer (9) through a wireless transmission device (13).

2. The device for measuring and evaluating the quality of the soil-rock contact surface of the side slope according to claim 1, characterized in that: The resistivity probe (10) is arranged along the slope body array.

3. The device for measuring and evaluating the quality of the soil-rock contact surface of the side slope according to claim 1, characterized in that: The extension rod (6) is a spiral type.

4. The device for measuring and evaluating the quality of the soil-rock contact surface of the side slope according to claim 1, characterized in that: The ultrasonic transducer (9) has two, and the other ultrasonic transducer (9) is horizontally arranged on the base (1) near one side of the slope body.

5. A method of using the device for measuring and evaluating the quality of the soil-rock contact surface of a slope according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: S1, determining a to-be-measured soil-rock interface region of a slope, placing a base (1) and fixing it with a fixing bolt (2); S2, drilling a hole in the to-be-measured soil-rock interface of the slope, and installing an ultrasonic transducer (9) into the hole; S3, inserting a resistivity probe (10) into the surface of the to-be-measured soil-rock interface of the slope; S4, moving a shear force measuring head (8) to the surface of the to-be-measured soil-rock interface of the slope through a sliding block (7) and an extension rod (6); S5, transmitting the measured interface data of the ultrasonic transducer (9), the resistivity probe (10) and the shear force measuring head (8) to a processor (12) through a wireless transmission device (13) and an electric wire (11); S6, constructing an interface quality index based on the interface data and grading the interface bonding quality by the processor (12).

6. The method of using the device for measuring and evaluating the quality of the soil-rock contact surface of the side slope according to claim 5, characterized in that: The formula for constructing the interface quality index in step S6 is as follows: ； In the formula, Iqi represents the interface quality index; V represents the measured ultrasonic wave speed; represents the measured shear strength; represents the measured resistivity; are weight coefficients; are reference values of the ultrasonic wave speed, the shear strength and the resistivity, respectively.

7. The method of using the device for measuring and evaluating the quality of the soil-rock contact surface of the side slope according to claim 6, characterized in that: The drilling depth of the to-be-measured soil-rock interface in step S2 is 15 cm.

8. The method of using the device for measuring and evaluating the quality of the soil-rock contact surface of the side slope according to claim 6, characterized in that: The spacing of the resistivity probe (10) in step S3 is not more than 10 cm.

9. The method of using the device for measuring and evaluating the quality of the soil-rock contact surface of the side slope according to claim 6, characterized in that: The number of measuring points of the shear force measuring head (8) in step S4 is not less than 5.

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