Ground-inserted non-pressure shear wave excitation device for single-hole wave velocity testing

Abstract

The present invention discloses a ground-inserted non-weighted shear wave excitation device for single-hole wave velocity testing, including a winged excitation plate slot, a pad holder, a pad, a detector fixing slot and a detector; the winged excitation plate slot is a rectangular parallelepiped without a top cover on the upper part, including a pair of main boards in the length direction, a bottom plate and two side plates in the width direction extending downward to form two side wing plates with isosceles triangles protruding from the bottom surface of the bottom plate at the lower part, and a circular hole is opened at both ends of the lower part of the two side wing plates in the winged excitation plate slot; the pad holder is composed of a round rod, a spring sleeved on the round rod, a spring limit head fixed at one end of the round rod, and a clamp fixed at the other end of the round rod; the detector fixing slot is fixed on the center of the bottom plate in the winged excitation plate slot, and the detector is coupled and fixed on the detector fixing slot. The problem of loose fit between the excitation board and the ground in the original method is avoided, and the weight problem in single-hole wave velocity testing in sites with complex terrain such as mountainous areas is solved.

Description

Technical Field

[0001] The invention relates to the field of geotechnical engineering investigation, and in particular to a ground-inserted non-pressure shear wave excitation device for single-hole wave velocity testing. Background Art

[0002] In the field of geotechnical engineering investigation, single-hole wave velocity test is a commonly used in-situ test method for testing the shear wave velocity of rock and soil layers. According to relevant specifications, single-hole wave velocity test should be carried out in the early investigation of construction projects to measure the shear wave (i.e. shear wave) velocity of rock and soil layers, and the equivalent shear wave velocity of the site is calculated based on the shear wave velocity value of each rock and soil layer, and then the site category is determined, providing parameter basis for building seismic analysis and verification.

[0003] The ground excitation of the single-hole wave velocity test mostly adopts the wooden board weighting and knocking method, that is, the square wooden board is placed flat on the ground, so that the line connecting the center of the wooden board and the hole is perpendicular to the length direction of the wooden board, and then a heavy object (greater than 500kg) is pressed on the wooden board, or a car is used to press its wheels on the wooden board, and then the two ends of the wooden board are knocked with a sledgehammer to make the wooden board rub against the ground, thereby exciting the soil layer to vibrate and generate shear waves. The difficulty of this shear wave excitation method is mainly to achieve weight pressing and effectively ensure that the excitation wooden board fits tightly with the ground. If the test borehole is located in a mountainous area with complex terrain, it is difficult to achieve weight pressing, and the overly long wooden board is not very convenient to carry. In particular, due to ground conditions, the wooden board is not closely attached to the ground, so that shear waves with sufficient energy cannot be obtained, which reduces the test effect and test capability. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a ground-inserted non-weighted shear wave excitation device for single-hole wave velocity testing, which improves the excitation effect of shear waves and increases the effective energy of shear waves, while solving the weight problem in single-hole wave velocity testing in complex terrain sites such as mountainous areas.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: a ground-inserted non-pressure shear wave excitation device for single-hole wave velocity testing, comprising a winged excitation plate slot, a pad holder, a pad, a detector fixing slot and a detector; the winged excitation plate slot is a rectangular parallelepiped without a top cover on the upper part, comprising a pair of main plates in the length direction, a bottom plate and two side plates in the width direction extending downward to form two side wing plates with isosceles triangles protruding from the bottom surface of the bottom plate, and a circular hole is opened at both ends of the lower part of the two side wing plates in the winged excitation plate slot; The plate holder is composed of a round rod, a spring sleeved on the round rod, a spring limit head fixed at one end of the round rod, and a clamping plate fixed at the other end of the round rod; there are 4 pad holders, the round rod passes through the wing plate through the round hole on the wing plate, so that the clamping plate is located on the outside of the wing plate, the spring and the spring limit head are located inside the slot of the winged excitation plate, and the two pads are clamped on the outside of the wing plates at both ends of the slot of the winged excitation plate by the telescopic round rod when in telescopic use, the detector fixing slot is fixed on the center of the bottom plate in the slot of the winged excitation plate, and the detector coupling is fixed on the detector fixing slot.

[0006] The detector is coupled and fixed on the detector fixing groove by screwing or gluing.

[0007] The material of the winged excitation plate groove and the pad fixer is steel, and the pad is made of wood or rubber.

[0008] The spring limit head and the clamping plate are welded on the round rod.

[0009] The clamping plate is welded on the round rod, and the spring limit head is screwed on the round rod through threads.

[0010] The beneficial effects of the present invention are as follows: the device of the present invention is mainly processed with steel materials, the length and width of the excitation plate can be adjusted during manufacturing and processing according to site conditions and the need for portability, and the length of the wing plate and the angle of the cone tip can also be reasonably adjusted according to the conditions of the surface soil layer. This device is driven in, which avoids the problem of loose fit between the excitation board and the ground in the original method, and solves the weight problem in the single-hole wave velocity test in complex terrain sites such as mountainous areas. This not only improves the effect of shear wave excitation and enhances the energy of the shear wave, but also solves the weight problem. This device has been used many times in actual projects with good results. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a three-dimensional schematic diagram of the ground-inserted non-pressure shear wave excitation device used for single-hole wave velocity testing of the present invention.

[0012] Figure 2 It is a three-dimensional schematic diagram of the winged exciting plate slot of the ground-inserted non-pressure shear wave excitation device for single-hole wave velocity testing of the present invention.

[0013] Figure 3It is a top view of the structure of the ground-inserted non-pressure shear wave excitation device for single-hole wave velocity testing of the present invention.

[0014] Figure 4 It is a three-dimensional schematic diagram of a pad holder of a ground-inserted non-weighted shear wave excitation device for single-hole wave velocity testing according to the present invention. DETAILED DESCRIPTION

[0015] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0016] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] like Figure 1As shown in FIG. 4 , the ground-inserted non-pressure shear wave excitation device for single-hole wave velocity testing of the present invention comprises a winged excitation plate slot 1, a pad holder 2, a pad 3, a detector fixing slot 4 and a detector 5; the winged excitation plate slot 1 is a rectangular parallelepiped without a top cover on the upper part, comprising a pair of main plates 11 in the length direction, a bottom plate 14 and two side plates in the width direction extending downward to form two side wing plates 12 protruding from the bottom surface of the bottom plate 14 in an isosceles triangle at the lower part, and a circular hole 13 is opened at both ends of the lower part of the two side wing plates 12 in the winged excitation plate slot 1; the pad holder 2 is composed of a round rod 21, which is sleeved on the round rod The spring 22 on the round rod, the spring limit head 23 fixed at one end of the round rod and the clamping plate 24 fixed at the other end of the round rod; there are 4 pad holders 2, the round rod 21 passes through the wing plate through the round hole 13 on the wing plate, so that the clamping plate 24 is located on the outside of the wing plate 12, the spring 22 and the spring limit head 23 are located inside the winged excitation plate slot 1, and the two pads 3 are clamped on the outside of the wing plates 12 at both ends of the winged excitation plate slot by the telescopic round rod 21 when telescopic use is achieved, the detector fixing slot 4 is fixed on the center of the bottom plate in the winged excitation plate slot 1, and the detector 5 is coupled and fixed on the detector fixing slot 4.

[0019] The detector 5 is coupled and fixed on the detector fixing groove 4 by screwing or gluing.

[0020] The material of the winged excitation plate slot 1 and the pad fixer 2 is steel, and the material of the pad 3 is wood or rubber.

[0021] The spring stopper 23 and the clamping plate 24 are welded on the round rod 21. Or the clamping plate 24 is welded on the round rod 21, and the spring stopper 23 is screwed on the round rod 21 by threads.

[0022] When in use, place the winged excitation plate slot 1 horizontally on the ground, with the tip of the wing plate 12 pointing vertically downward, and insert the wing plate 12 into the ground by hammering or static pressure. Then hammer the pads 3 on the pad holders 2 at both ends of the winged excitation plate slot, so that the wing plate 12 will vibrate the ground soil and generate transverse waves to propagate in the stratum. The detector fixing slot 4 is used to fix the detector 5 during the test process. When the pads at both ends of the excitation plate are struck, the detector 5 will vibrate and generate signals, thereby triggering the timing.

[0023] In this embodiment, the body of the winged excitation plate is groove-shaped, and the lower part of the wing plate is an isosceles triangle, which can be welded from 5mm±5mm thick steel plate. The length of the winged excitation plate groove 1 is controlled in the range of 1.0 to 2.0m, and the width is controlled in the range of 20cm±5cm; the width of the wing plate is adapted to the width of the plate body, and the height of the wing plate triangle is controlled in the range of 30cm±5cm.

[0024] The pad holder 2 is composed of a round rod 21, a spring 22, a clamping plate 24 and a spring limit head 23. The round rod 21 passes through the wing plate 12 through the round hole 13 on the wing plate to achieve retractability. The round hole 13 is located at both ends of the wing plate in the excitation plate groove in the width direction. When in use, the pad (wood or rubber) is clamped at both ends of the winged excitation plate through the round rod.

[0025] The round rod is a steel rod with a diameter of about 1.0 cm. The spring is passed through the rod and placed on the inner side of the wing of the winged excitation plate. The pad fixer clamp is welded on the round rod by a 10cm×5cm×0.5cm (adjustable) steel plate and placed on the outer side of the groove of the winged excitation plate. The spring limit head is a circular steel plate welded on the inner side of the spring rod, and its diameter can be slightly thicker than the spring rod.

[0026] The pad is a wooden or rubber plate, and the size of the plate can be 40cm×10cm×1.0cm (adjustable appropriately). The pad is located between the wing plate of the winged excitation plate and the clamping plate of the pad holder. When exciting shear waves, just knock on the pads at both ends of the winged excitation plate, which is beneficial to enhance the excitation effect and reduce impact noise.

[0027] The device of the present invention mainly solves the problem that the excitation board and the ground are not tightly fitted in the original method, and solves the problem of weight pressure on the excitation board in complex terrain sites such as mountainous areas. This device is a ground-inserted non-weighted shear wave excitation device. When in use, the wing plate of the winged excitation board is downward toward the ground, and the wing plate is inserted into the ground by hammering or static pressure to make it fit tightly with the foundation soil. Then the detector is installed on the detector fixing groove, and then a wooden board or rubber board is used as a pad to fix it between the pad holder clamp and the wing plate of the winged excitation board. After the device is firmly installed, the tester stands on the winged excitation board driven into the soil and uses a hammer to knock the pads at both ends of the winged excitation board, so that the wing plate drives the soil layer to vibrate and generate shear waves. The device is mainly processed with steel materials. The length and width of the excitation board can be adjusted according to the site conditions and the need for portability during production and processing. The length of the wing plate and the cone tip angle can also be reasonably adjusted according to the surface soil conditions.

[0028] The device of the present invention is a ground-inserted non-weighted shear wave excitation device. This device is driven into the soil layer when in use, which avoids the problem of not being able to ensure that the excitation plate fits closely to the ground, and the test can be completed without a large amount of weight, thus solving the weight problem in sites with complex terrain such as mountainous areas.

[0029] The embodiments described above are only used to illustrate the technical ideas and features of the present invention, and their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. The patent scope of the present invention cannot be limited only by this embodiment, that is, any equivalent changes or modifications made to the spirit disclosed by the present invention still fall within the patent scope of the present invention.

Claims

1. A ground-inserted non-pressure shear wave excitation device for single-hole wave velocity testing, characterized in that: The invention comprises a winged excitation plate slot (1), a pad holder (2), a pad (3), a detector fixing slot (4) and a detector (5); the winged excitation plate slot (1) is a rectangular parallelepiped without a top cover on the upper part, comprising a pair of main plates (11) in the length direction, a bottom plate (14) and two side plates in the width direction extending downward to form two side wing plates (12) protruding from the bottom surface of the bottom plate (14) in an isosceles triangle at the lower part, and a circular hole (13) is provided at both ends of the lower part of the two side wing plates (12) in the winged excitation plate slot (1); the pad holder (2) is composed of a round rod (21), a spring (22) sleeved on the round rod, a spring stopper (23) fixed at one end of the round rod and a clamping plate (24) fixed at the other end of the round rod; there are four pad holders (2), The round rod (21) passes through the wing plate through the round hole (13) on the wing plate, so that the clamping plate (24) is located outside the wing plate (12), and the spring (22) and the spring limit head (23) are located inside the winged excitation plate slot (1). When the winged excitation plate slot is telescopic, the two pads (3) are clamped on the outside of the wing plates (12) at both ends of the winged excitation plate slot by the telescopic round rod (21). The detector fixing slot (4) is fixed on the center of the bottom plate in the winged excitation plate slot (1). The detector (5) is coupled and fixed to the detector fixing slot (4). The detector (5) is coupled and fixed to the detector fixing slot (4) by screwing or gluing. The winged excitation plate slot (1) and the pad holder (2) are made of steel, and the pad (3) is made of wood or rubber.

2. The ground-inserted non-pressure shear wave excitation device for single-hole wave velocity testing according to claim 1 is characterized in that: The spring limit head (23) and the clamping plate (24) are welded to the round rod (21).

3. The ground-inserted non-pressure shear wave excitation device for single-hole wave velocity testing according to claim 1 is characterized in that: The clamping plate (24) is welded to the round rod (21), and the spring limit head (23) is screwed to the round rod (21) through threads.

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