Underwater foundation bearing capacity measurement and geotechnical property identification device and method

Abstract

An underwater foundation bearing capacity measurement and geotechnical property identification device and method. While a power cylinder (1) drives a movable rotating shaft (7) to rotate, a heavy hammer lock (11) fixedly connected to the movable rotating shaft (7) repeatedly drives a heavy hammer (12) to be vertically lowered and lifted on a hammering rod (3), and the heavy hammer lock (11) is automatically unlocked by means of a stop head (24) such that the heavy hammer (12) hammers a self-locking cushion block (13), with a single hammering distance remaining unchanged, a drill bit (23) at the bottom end of the hammering rod (3) is driven to penetrate into the stratum, and a penetration displacement and the number of times of hammering are recorded.

Description

A device and method for detecting underwater foundation bearing capacity and identifying rock and soil properties Technical Field

[0001] The present invention relates to the field of marine geotechnical engineering technology, and in particular to a device and method for detecting underwater foundation bearing capacity and identifying geotechnical properties. Background Art

[0002] Before the construction of existing offshore or underwater projects, it is necessary to test the bearing capacity of the underwater foundation and understand the geotechnical properties to ensure that the bearing capacity of the foundation meets the design requirements. The current methods for testing the bearing capacity of underwater foundations include: 1. Underwater foundation flat plate load test method, 2. Remolded soil sample piezoelectric effect method, and 3. Heavy hammer hammer method. The underwater foundation flat plate load test method uses step-by-step loading to obtain the relationship between the ballast amount and the amount of foundation soil settlement to estimate the foundation bearing capacity; the remolded soil sample triaxial shear test method uses underwater sampling and remolded soil sample triaxial shear test to estimate the underwater foundation bearing capacity; the heavy hammer hammer method uses the damage to the foundation caused by the free fall of the heavy hammer to estimate the bearing capacity of the underwater foundation.

[0003] However, the above detection methods all have many problems. The flat plate load test can accurately measure the bearing capacity of the underwater foundation, but the underwater lifting of the test bench using a large tugboat is costly, difficult, dangerous, and inefficient. For general projects, it is impossible to bear the time and economic costs of large-scale testing using the flat plate load method.

[0004] The reshaped soil sample triaxial shear test method involves sampling underwater, reshaping it in the laboratory, and then performing an indoor triaxial shear test on the reshaped sample. Currently, underwater stratified sampling technology is not feasible in deeper waters, and reshaped soil samples cannot reproduce the properties of soil under deep water and high pressure. Furthermore, the consolidation and drainage shear test cycle is long, exceeding 24 hours, making it inefficient and unsuitable for engineering applications.

[0005] The heavy hammer method is only suitable for bearing capacity testing of surface foundations. The soil bearing capacity is judged by detecting the penetration depth of the heavy hammer after it falls. It requires a large tugboat and is costly. At the same time, the heavy hammer method can only conduct qualitative research and not quantitative analysis. It requires divers to dive underwater for manual observation. The test error is large and it is not suitable for engineering applications.

[0006] Chinese invention patent application CN116856475A provides a device for detecting the bearing capacity of foundations of water conservancy projects, which is used in ground engineering environments. Its core hammer is driven by a motor to drive the cone head deep into the foundation, and the progress of the gear rack is counted. The length of the core hammer of the entire device cannot be extended, making it difficult to apply to underwater environments, and there is a problem of inaccurate counting method.

[0007] Chinese invention patent application CN115977055A provides a device and method for detecting the bearing capacity of the foundation of a water conservancy project. By setting up a driving mechanism and a fixing mechanism, it solves the problem that the gravity hammer cannot be coaxial with the probe rod after being reset. However, when this structure is applied to an underwater environment, due to the effects of tides and wind, the entire device will shake frequently, and it is impossible to ensure that the heavy hammer and the probe rod drill bit are coaxial during the continuous hammering process.

[0008] Chinese invention patent application CN115508231A provides a down-the-hole standard penetration tester for use in underwater environments. The test is conducted by dropping a hammer inside a casing to strike the drill bit into the ground. The arrangement of the entire device from the vessel to the drill bit is limited by the length of the casing. During underwater engineering inspections, the length of the casing needs to be changed according to the water depth, which is inconvenient and expensive to use. The experimental cycle of the inspection point is long and the efficiency is low.

[0009] Summary of the Invention

[0010] In order to solve the problems in the above-mentioned background technology, the present application provides an underwater foundation bearing capacity detection and rock and soil property identification device and method, which can apply the heavy hammer hammer method to underwater engineering foundation detection environments at different depths, does not rely on personnel diving underwater to assist in operation, and the obtained measurement and analysis data are accurate, and the detection and analysis results can be issued in a timely manner. The whole set of equipment has a low cost and can be used in offshore and underwater projects without being restricted by natural conditions such as water quality and water depth, and has high work efficiency.

[0011] To achieve the above objectives, the technical solutions provided by this application are as follows:

[0012] An underwater foundation bearing capacity detection and rock and soil property identification device, comprising:

[0013] A power output system comprising a power cylinder, a connecting rod, a movable rotating shaft and a fixed rotating shaft, wherein the power cylinder is connected to an onboard air compressor via an air pipe, and the output end of the power cylinder drives the movable rotating shaft to perform periodic circular motion around the fixed rotating shaft via the connecting rod;

[0014] The sounding hammer system includes a jack, a weight lock, a weight, a self-locking pad and a hammer rod, wherein the jack is fixedly connected to the power cylinder, the weight lock is fixedly connected to the movable rotating shaft by a steel wire rope, and the bottom end of the weight is fixedly connected to the self-locking pad by a steel wire rope, and the hammer rod is provided with a trapezoidal external thread along the axis length, and the hammer rod sequentially passes through the jack, weight lock, weight and self-locking pad from top to bottom; wherein the weight lock is driven by the movable rotating shaft to lock with the weight when it is lowered, and drives the weight to rise when it is lifted, and is released from the locked state through the jack; the self-locking pad has a self-locking gasket that is narrow at the top and wide at the bottom, which is combined with the external thread to form a self-locking structure, so that when the weight falls and hits the self-locking pad, it drives the bottom end drill bit of the hammer rod to penetrate the formation, and the self-locking pad keeps the distance between the two unchanged when it rises with the weight;

[0015] A correction system includes an inclinometer, a bracket assembly, and an adjustment assembly. The inclinometer is disposed at the upper end of the hammer rod. The bracket assembly is used to support and fix the inclinometer on the underwater surface. The adjustment assembly adjusts the support of the bracket assembly according to the inclination data of the inclinometer to keep the detection and identification device vertical.

[0016] The data acquisition system includes a displacement recorder, a revolution recorder, and a data analysis module, wherein the displacement recorder is arranged above the drill bit at the bottom end of the hammer rod, the revolution recorder is arranged on the fixed rotating shaft, and the inclinometer, displacement recorder, and revolution recorder are all communicatively connected to the data analysis module.

[0017] Compared with the existing technology, the present application drives the movable rotating shaft to rotate through the air cylinder, while the heavy hammer lock fixedly connected to the movable rotating shaft repeatedly drives the heavy hammer to be vertically lowered and lifted on the hammer rod, and automatically unlocks the hammer self-locking pad through the top head, keeping the single hammering distance unchanged, driving the drill bit at the bottom end of the hammer rod to penetrate the formation, recording the penetration displacement and the corresponding number of rotations (number of hammering), thereby achieving accurate calculation of the bearing capacity of the underwater foundation and identification of rock and soil properties, and is suitable for completing rapid detection tasks in different hydrological environments, changing the shortcomings of the hammer penetration method in underwater environments, such as complex operation, high cost and poor practicality, and being suitable for engineering application and promotion.

[0018] Preferably, the weight lock comprises an annular lock body and a symmetrical locking plate hinged on the inner ring of the lock body, wherein a lifting ring is fixedly provided on the lock body, the locking plate is connected to the inner ring by an elastic hinge and rotates with the elastic hinge as an axis, the locking plate comprises an integrally formed cross brace, a rotating body and a blocking portion, the rotating body being hinged to the inner ring of the lock body by an elastic hinge; the upper portion of the weight is concave and forms a weight blocking ring along the circumference, the locking plate enters the concave portion of the weight when lowering, and the blocking portion engages with the weight blocking ring to form a limited position fixation. Based on the above scheme, the locking plate and the weight can be engaged and fixed during the lowering process of the weight lock, and the weight can be lifted together during the lifting process; when the locking plate rises to the head position, the head penetrates through the cross brace, causing the locking plate to rotate around the elastic hinge, the blocking portion gathers and separates from the fixed position of the weight blocking ring, and the weight is released from the locked state and falls to hit the self-locking pad.

[0019] Specifically, the self-locking pad includes a hammer block and a self-locking washer, wherein the cross-section of the self-locking washer is a trapezoid that is narrow at the top and wide at the bottom, and has an internal thread. A cavity is opened in the hammer block to accommodate the self-locking washer, and a lifting ring is provided on the hammer block. The hammer rod passes through the middle of the self-locking pad. The trapezoidal external thread and the internal thread of the self-locking washer are engaged, and the hammer block drives the self-locking washer to be lifted along with the heavy hammer, so that the self-locking pad can be freely lifted on the hammer rod without affecting the depth of the hammer rod having penetrated into the formation. When the self-locking pad is struck and falls by the heavy hammer, the self-locking washer and the hammer rod are self-locked in the falling direction, driving the hammer rod to penetrate into the formation, thereby converting the hammering force of the heavy hammer on the self-locking pad into a driving force for the hammer rod to penetrate into the formation.

[0020] Furthermore, the support assembly includes a hollow support plate and a support rod. One end of the support rod is rotatably connected to the support plate, and the other end is a pointed tip for being inserted into the stratum for fixation. The support rod includes at least three rods.

[0021] Furthermore, the adjustment assembly includes a sleeve, a hydraulic rod and a clamp, wherein the sleeve is fixedly connected to the support plate, the displacement recorder is fixedly arranged in the sleeve, the hammer rod passes through the support plate and the sleeve in sequence, and the hydraulic rod is fixedly connected to the support rod through the clamp.

[0022] Furthermore, the movable rotating shaft and the connecting rod are connected through a driving connecting rod, a crankshaft is provided at the connection between the connecting rod and the driving connecting rod, a crankshaft protective cover is provided outside the crankshaft, the rotating shaft radius of the fixed rotating shaft is larger than that of the movable rotating shaft, and the movable rotating shaft performs a fixed-axis circular rotation around the fixed rotating shaft.

[0023] Furthermore, the inclinometer can be selected from a mechanical compass, a laser compass, and a fiber optic compass for real-time posture measurement; and the displacement recorder is a gear recorder that can engage with the external thread on the hammer rod.

[0024] A method for detecting and identifying the bearing capacity of an underwater foundation, comprising the following specific steps:

[0025] S1: Transport the test vessel carrying the detection and identification device to the designated waters and anchor the vessel;

[0026] S2: Put the above detection and identification device into water, and adjust the hydraulic rod according to the tilt data measured by the inclinometer to keep the device vertically fixed;

[0027] S3: Start the onboard air compressor to supply air to the power cylinder, driving the heavy hammer to move up or down along the hammer rod;

[0028] S4: Analyze the data recorded by the revolution recorder and displacement recorder to identify the geotechnical properties and estimate the bearing capacity of the underwater foundation.

[0029] Furthermore, in step S3, the power cylinder drives the weight to lift and lower the weight as follows:

[0030] S301: The power cylinder drives the connecting rod downward, causing the movable shaft to rotate in a circle around the fixed shaft;

[0031] S302: The movable shaft rotates from top to bottom, driving the weight lock to penetrate the weight and clamp and fix it;

[0032] S303: When the movable shaft moves from bottom to top, the weight lock drives the weight to be lifted up, and the weight drives the self-locking pad to be lifted up along the hammer rod through the steel wire rope with a fixed spacing;

[0033] S304: When the weight lock is lifted to the jack, the jack penetrates the weight lock, and the weight lock is unlocked and falls.

[0034] S305: The heavy hammer falls and strikes the self-locking pad, driving the hammer rod locked in the downward direction with the self-locking pad to penetrate the formation;

[0035] S306: The revolution recorder records the number of revolutions of the fixed shaft as the number of hammer strikes, and the displacement recorder records the displacement of the hammer rod as the depth of penetration into the formation.

[0036] Furthermore, the specific steps of analyzing the data in step S4 are:

[0037] S401: Calculate fixed formation penetration △L n and the corresponding hammer number N n ;

[0038] S402: Calculate the number of hammer blows N corresponding to the fixed penetration L by difference, and estimate the characteristic value of the bearing capacity of the soil layer;

[0039] S403: Correct the standard value of the number of hammer blows N' based on the test of the bearing capacity of underwater foundation in the same classification of soil layer;

[0040] S404: Correct the values ​​of the hammer rod length, the buoyancy of the hammer, and the resistance of the hammer in water, draw an analysis curve, and evaluate and identify the bearing capacities of different underwater foundations.

[0041] The beneficial effects of the present invention are:

[0042] 1. The core method of the present invention adopts the dynamic probing method, which eliminates the technical difficulties of the underwater foundation plate load test method, the reshaped soil sample piezoelectric effect method, and the heavy hammer hammer method, which are caused by hydrological factors (water quality, water depth), the high error and high cost of the test results caused by the need for personnel to dive underwater for assistance.

[0043] 2. The detection device of the present invention uses a ship-borne air compressor to provide power for the cylinder. In the face of hydrological environments at different depths, it is only necessary to lengthen the air delivery pipe and the hammer rod to realize the underwater bearing capacity detection and rock and soil property identification, which greatly reduces the cost and difficulty of use of the detection device.

[0044] 3. The present invention uses a self-locking pad to achieve the purpose of hitting the self-locking pad when the heavy hammer falls, and relies on self-locking to drive the hammer rod to penetrate the formation. The self-locking pad does not affect the depth of the hammer rod that has penetrated the formation during the process of the heavy hammer being lifted up, and the distance between the heavy hammer and the self-locking pad is controlled by a fixed steel wire rope, which can keep the falling distance of each hammering consistent.

[0045] 4. The present invention adopts a weight lock which penetrates into the weight to fix it when it is lowered, drives the weight to rise when it is lifted, and unlocks the weight through the head, so that the weight is separated from the weight lock and falls; thus, the automatic lifting and lowering of the weight is realized.

[0046] 5. Through the above design, the present invention uses the number of revolutions and displacement as directly measured data and corrects the influence of the underwater environment on the data, cleverly solving the scientific statistical and computational analysis of the number of hammer blows and penetration volume. It is suitable for wide application in marine geotechnical engineering. The analysis data results can be obtained immediately. The retractable device is simple to use, which improves work efficiency. The equipment is simple to process and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] FIG1 is a diagram showing the overall internal structure of a detection device according to an embodiment of the present invention;

[0048] FIG2 is a cross-sectional view of the overall structure of the detection device according to an embodiment of the present invention;

[0049] FIG3 is a cross-sectional view of a self-locking pad according to an embodiment of the present invention;

[0050] FIG4 is an overall view of a self-locking gasket in an embodiment of the present invention;

[0051] FIG5 is a schematic diagram of a weight lock and a weight locking device according to an embodiment of the present invention;

[0052] FIG6 is a schematic diagram of a weight lock and a weight lock release in an embodiment of the present invention.

[0053] In the figure, marks 1-power cylinder, 2-air pipe, 3-hammer rod, 4-connecting rod, 5-crankshaft, 6-driving connecting rod, 7-movable shaft, 8-fixed shaft, 9-divider, 10-wire rope, 11-weight lock, 1101-lifting ring, 1102-elastic hinge, 1103-cross support part, 1104-rotating body, 1105-blocking part, 1106-hollow channel, 12-weight , 1201-weight hammer cavity, 1202-weight hammer retaining ring, 13-self-locking pad, 1302-hammer block, 1303-self-locking gasket, 1304-locking block cavity, 1305-locking block channel, 14-support plate, 15-support rod, 16-hydraulic rod, 17-clamp, 18-sleeve, 19-displacement recorder, 21-revolution recorder, 22-tip, 23-drill bit, 24-head. DETAILED DESCRIPTION

[0054] The technical solutions of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. The components of the present invention generally described and shown in the drawings herein can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the present invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making any creative efforts are within the scope of protection of the present invention.

[0055] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, "connection" can be a detachable connection or a non-detachable connection; it can be a direct connection or an indirect connection through an intermediate medium. Among them, "fixed connection" means that they are connected to each other and the relative position relationship remains unchanged after the connection. It should be understood that when component A is fixedly connected to component C through component B, changes in the relative position relationship caused by the deformation of component A, component B and component C itself are allowed. "Rotational connection" means that they are connected to each other and can rotate relative to each other after the connection. "Sliding connection" means that they are connected to each other and can slide relative to each other after the connection. Among them, the two components are integrated into an integrated structure through an integrated molding process, which means that in the process of forming one of the two components, the component is connected to the other component, and there is no need to connect the two components together through reprocessing (such as bonding, welding, snap connection, screw connection).

[0056] The directional terms mentioned in the embodiments of the present application, such as "upper", "lower", "side", "top", "bottom", etc., are only references to the directions in the drawings. Therefore, the directional terms used are for better and clearer explanation and understanding of the embodiments of the present application, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0057] The term "plurality" means at least two. The term "above" includes the number itself. The term "and / or" is a description of an association relationship between associated objects, indicating that three relationships may exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. Terms such as "first" and "second" are used for descriptive purposes only and cannot be understood as implying or suggesting relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features.

[0058] Example

[0059] In order to apply the dynamic penetration method to underwater engineering foundation detection environments at different depths without relying on personnel to dive underwater for auxiliary operation, obtain accurate measurement and analysis data, and solve the problems existing in the background technology, the present invention discloses an underwater foundation bearing capacity detection and geotechnical property identification device. Please refer to the overall diagram of Figures 1-2. The device comprises four parts: a ship-borne air compressor and power output system, a penetration hammer system, a correction system, and a data acquisition system, among which:

[0060] The power output system includes a power cylinder 1, a connecting rod 4, a movable rotating shaft 7 and a fixed rotating shaft 8, wherein the power cylinder 1 is connected to the ship's air compressor through an air pipe 2, and the air compressor provides a power source for the intermittent air supply to the power cylinder 1. The output end of the power cylinder 1 is driven by the connecting rod 4, and the movable rotating shaft 7 is driven by the driving connecting rod 6. A crankshaft 5 is provided at the connection between the connecting rod 4 and the driving connecting rod 6, and a crankshaft protective sleeve is provided on the outside of the crankshaft 5. The crankshaft 5 converts the power from the power cylinder 1 into a movable rotating shaft 7 that performs periodic circular motion around the fixed rotating shaft 8, wherein the rotating shaft radius of the fixed rotating shaft 8 is larger than that of the movable rotating shaft 7, and the two form a nearly elliptical rotating body. A revolution recorder 21 is provided in the fixed rotating shaft 8 for recording the number of revolutions of the movable rotating shaft 7 around the fixed rotating shaft 8.

[0061] Please refer to Figures 3-6. The detection device of the present invention also includes a probing hammer system, which includes a plug 24, a weight lock 11, a weight 12, a self-locking pad 13, a splitter 9, and a hammer rod 3. The splitter 9 is fixedly connected to the outer shell of the power cylinder 1, the plug 24 is fixed to the outer shell of the power cylinder 1 and extends out of the splitter 9, the weight lock 11 is fixedly connected to the movable shaft 7 through a wire rope 10, and the splitter 9 connects the wire rope 10 connected to the movable shaft 7 to the weight lock 11. The two ends of the hammer lock 11 are kept balanced, and the bottom end of the heavy hammer 12 is fixedly connected to the self-locking pad 13 through a wire rope 10, so that the distance between the two remains unchanged, ensuring that the hammering distance is the same each time. The hammer rod 3 is provided with a trapezoidal external thread along the axis length, and the hammer rod 3 passes through the top head 24, the outer shell of the power cylinder 1, the distributor 9, the heavy hammer lock 11, the heavy hammer 12, the self-locking pad 13, the support plate 14 and the sleeve 18 from top to bottom, and finally penetrates into the formation through the drill bit 23 at the bottom end of the hammer rod 3.

[0062] Please refer to the locking and unlocking diagrams of Figures 5-6, wherein the weight lock 11 is locked with the weight 12 when lowered by the rotation of the movable shaft 7, and is driven to rise when lifted, and is released from the locked state by the head 24; the weight lock 11 includes an annular lock body and a symmetrical locking plate hinged on the inner ring of the lock body, wherein the lock body is fixedly provided with a lifting ring 1101, and the locking plate is connected to the inner ring by an elastic hinge 1102 and is connected to the elastic hinge 1102. For axial rotation, the locking plate includes an integrally formed cross support portion 1103, a rotating body 1104 and a blocking portion 1105, and the rotating body 1104 is hinged to the inner ring of the lock body through an elastic hinge 1102; the upper part of the weight 12 is concave as a weight cavity 1201, and a weight blocking ring 1202 is formed along the circumference, and the locking plate enters the weight cavity 1201 of the weight 12 when lowered, and the blocking portion 1105 is engaged with the weight blocking ring 1202 to form a limited fixation. Based on the above scheme, during the lowering process of the weight lock 11, the locking plate and the weight 12 can be locked and fixed, and during the lifting process, the weight 12 can be lifted up together. When the locking plate rises to the position of the head 24, the head 24 penetrates through the cross support part 1103, causing the locking plate to rotate around the elastic hinge 1102, and the blocking part 1105 gathers and separates from the fixed limit of the weight block ring 1202, and the weight 12 is released from the locked state and falls to hit the self-locking pad 13.

[0063] The self-locking pad 13 has a self-locking gasket 1303 that is narrow at the top and wide at the bottom, and a hammer block 1302 that is struck by the falling hammer 12. The self-locking gasket 1303 has an internal thread that combines with the external thread to form a self-locking structure. The specific structure is that a locking block cavity 1304 is opened in the hammer block 1302 to accommodate the self-locking gasket 1303, and a hanging ring 1101 is set on the hammer block 1302. The middle of the self-locking pad 13 is a hollow locking block channel 1305 for passing through the hammer rod 3. By meshing the trapezoidal external thread and the internal thread of the self-locking gasket 1303, the hammer block 1302 drives the self-locking gasket 1303 to rise along with the heavy hammer 12, so that the self-locking gasket 13 can be lifted freely on the hammer rod 3 without being pulled up to affect the depth of the hammer rod 3 penetrated into the formation. When the self-locking gasket 13 is hammered down by the heavy hammer 12, the self-locking gasket 1303 and the hammer rod 3 in the falling direction form a self-locking, which drives the hammer rod 3 to penetrate into the formation, thereby converting the hammering force of the heavy hammer 12 on the self-locking gasket 13 into a driving force for the hammer rod 3 to penetrate into the formation.

[0064] It also includes a correction system, including a high-precision compass attitude meter, a bracket assembly and an adjustment assembly, the compass attitude meter is arranged at the upper end of the hammer rod 3, the bracket assembly is used to support and fix it on the underwater surface, and the adjustment assembly adjusts the support of the bracket assembly according to the inclination data of the inclinometer to keep the detection and identification device vertical; wherein the bracket assembly includes a hollow support plate 14 and a support rod 15, one end of the support rod 15 is rotatably connected to the support plate 14, and the other end is a pointed head 22 for being inserted into the formation for fixation, and there are six support rods 15; the adjustment assembly includes a sleeve 18, a hydraulic rod 16 and a clamp 17, wherein the sleeve 18 is fixedly connected to the support plate 14, and the displacement recorder 19 is fixedly arranged in the sleeve 18, and the hydraulic rod 16 is fixedly connected to the support rod 15 through the clamp 17, wherein the displacement recorder 19 is a gear recorder that can engage with the external thread on the hammer rod 3.

[0065] The present invention also provides a method for underwater foundation detection and rock and soil property identification using the above detection device, the specific steps comprising:

[0066] S1: Transport the test vessel carrying the detection and identification device to the designated waters, determine the latitude and longitude of the detection point through GNSS positioning, and anchor the vessel;

[0067] S2: Put the above detection and identification device into water, and adjust the adjustment component (hydraulic rod) according to the tilt data measured by the inclinometer to keep the device vertically fixed;

[0068] S3: Start the onboard air compressor to supply air to the power cylinder, driving the heavy hammer to move up or down along the hammer rod;

[0069] S4: By analyzing the values ​​recorded by the revolution recorder and displacement recorder, the bearing capacity and geotechnical properties of the underwater foundation are inferred.

[0070] The process steps of the power cylinder driving the weight to lift and lower in step S3 are as follows:

[0071] S301: The power cylinder drives the connecting rod downward, causing the movable shaft to rotate in a circle around the fixed shaft;

[0072] S302: The movable shaft rotates from top to bottom, driving the weight lock to penetrate the weight and clamp and fix it;

[0073] S303: When the movable shaft moves from bottom to top, the weight lock drives the weight to be lifted up, and the weight drives the self-locking pad to be lifted up along the hammer rod through the steel wire rope with a fixed spacing;

[0074] S304: When the weight lock is lifted to the jack, the jack penetrates the weight lock, and the weight lock is unlocked and falls.

[0075] S305: The heavy hammer falls and strikes the self-locking pad, driving the hammer rod locked in the downward direction with the self-locking pad to penetrate the formation;

[0076] S306: The revolution recorder records the number of revolutions of the fixed shaft as the number of hammer strikes, and the displacement recorder records the displacement of the hammer rod with the fixed shaft as the depth of penetration into the formation.

[0077] The specific steps of analyzing the data in step S4 are:

[0078] S401: Calculate fixed formation penetration △L n and the corresponding hammer number N n ;

[0079] S402: Calculate the number of hammer blows N corresponding to the fixed penetration L by difference, and estimate the characteristic value of the bearing capacity of the soil layer;

[0080] S403: Correct the standard value of the number of hammer blows N' based on the test of the bearing capacity of underwater foundation in the same classification of soil layer;

[0081] S404: Correct the values ​​of hammer rod length, hammer buoyancy, and hammer resistance in water, draw analysis curves, and estimate the bearing capacity of different underwater foundations and identify geotechnical properties.

[0082] The correction of the hammer rod length, the buoyancy of the hammer, and the resistance of the hammer in water in S404 is as follows:

[0083] N=αβs N'

[0084] N—corrected hammer blow number;

[0085] N'—measured number of hammer blows;

[0086] (1)α——Underwater bearing capacity rod length correction factor. When the threaded hammer rod needs to be lengthened, the number of hammer blows can be corrected for rod length according to the following formula

[0087] (2) β - correction coefficient of the water buoyancy of the weight in the underwater bearing capacity estimation test. The underwater bearing capacity test requires correction of the weight volume, and the buoyancy of the weight in water must be considered (buoyancy is a parameter related to volume).

[0088] (3) s - correction factor for the cross-sectional area of ​​the weight in the underwater bearing capacity estimation test. The underwater bearing capacity test requires correction of the weight volume, and the resistance of the weight in water must be considered (water resistance is a parameter related to the cross-sectional area of ​​the weight).

[0089] Method for estimating underwater bearing capacity of different soil masses

[0090] Shape identification method of rock and soil mass

[0091] The core method of the present invention adopts the dynamic penetration method, which eliminates the need for underwater foundation plate load test.

[0092] The existing methods of testing, such as the piezoelectric effect method for reshaped soil samples, and the heavy hammer impact method, suffer from technical difficulties such as inaccurate test results due to the hydrological environment, high errors, and high costs due to the need for underwater assistance. The detection and identification device of the present invention uses a shipboard air compressor to power the cylinder. To estimate underwater bearing capacity and identify geotechnical properties in hydrological environments of varying depths, simply lengthen the air delivery pipe and extend the hammer rod, significantly reducing the cost and difficulty of use of the detection and identification device.

[0093] It is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims be included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved. In addition, it should be understood that although this specification is described in terms of implementation methods, not each implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity, and those skilled in the art should regard the specification as a whole. The technical solutions in the various embodiments can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. An underwater foundation bearing capacity detection and rock and soil property identification device, characterized in that The device comprises: A power output system comprising a power cylinder, a connecting rod, a movable rotating shaft and a fixed rotating shaft, wherein the power cylinder is connected to an onboard air compressor via an air pipe, and the output end of the power cylinder drives the movable rotating shaft to perform periodic circular motion around the fixed rotating shaft via the connecting rod; The sounding hammer system includes a jack, a weight lock, a weight, a self-locking pad and a hammer rod, wherein the jack is fixedly connected to the power cylinder, the weight lock is fixedly connected to the movable rotating shaft by a steel wire rope, and the bottom end of the weight is fixedly connected to the self-locking pad by a steel wire rope, and the hammer rod is provided with a trapezoidal external thread along the axis length, and the hammer rod sequentially passes through the jack, weight lock, weight and self-locking pad from top to bottom; wherein the weight lock is driven by the movable rotating shaft to lock with the weight when it is lowered, and drives the weight to rise when it is lifted, and is released from the locked state through the jack; the self-locking pad has a self-locking gasket that is narrow at the top and wide at the bottom, which is combined with the external thread to form a self-locking structure, so that when the weight falls and hits the self-locking pad, it drives the bottom end drill bit of the hammer rod to penetrate the formation, and the self-locking pad keeps the distance between the two unchanged when it rises with the weight; The correction system includes an inclinometer, a bracket assembly, and an adjustment assembly. The inclinometer is provided on the bracket assembly. The bracket assembly is used to support and fix the inclinometer on the underwater surface. The adjustment assembly adjusts the support of the bracket assembly according to the inclination data of the inclinometer to keep the detection and identification device vertical. The data acquisition system includes a displacement recorder, a revolution recorder and a data analysis module, wherein the displacement recorder is arranged above the drill bit at the bottom end of the hammer rod, and the revolution recorder is arranged above the drill bit at the bottom end of the hammer rod. The device is arranged on the fixed rotating shaft, and the inclinometer, displacement recorder and revolution recorder are all communicatively connected with the data analysis module.

2. The device according to claim 1, characterized in that The weight lock includes an annular lock body and a symmetrical locking plate hinged on the inner ring of the lock body, wherein a hanging ring is fixedly provided on the lock body, the locking plate is connected to the inner ring by an elastic hinge and rotates around the elastic hinge, the locking plate includes an integrally formed cross bracing portion, a rotating body and a blocking portion, the rotating body is hinged to the inner ring of the lock body by an elastic hinge; the upper part of the weight is concave and forms a weight blocking ring along the circumferential direction, and the locking plate enters the concave part of the weight when lowered, and the blocking portion engages with the weight blocking ring to form a limited fixation.

3. The device according to claim 1, characterized in that The self-locking pad includes a hammer block and a self-locking gasket, wherein the cross-section of the self-locking gasket is a trapezoid that is narrow at the top and wide at the bottom and has an internal thread. A cavity is opened in the hammer block to accommodate the self-locking gasket. A hanging ring is provided on the hammer block, and the hammer rod passes through the middle of the self-locking pad.

4. The device according to claim 1, characterized in that The support assembly includes a hollow support plate and a support rod. One end of the support rod is rotatably connected to the support plate, and the other end is a pointed head for being inserted into the stratum for fixation. The support rod includes at least three rods.

5. The device according to claim 1, characterized in that The adjustment assembly includes a sleeve, a hydraulic rod and a clamp, wherein the sleeve is fixedly connected to the support plate, the displacement recorder is fixedly arranged in the sleeve, the hammer rod passes through the support plate and the sleeve in sequence, and the hydraulic rod is fixedly connected to the support rod through the clamp.

6. The device according to claim 1, characterized in that The movable rotating shaft is connected to the connecting rod through a driving connecting rod. A crankshaft is provided at the connection between the connecting rod and the driving connecting rod. A crankshaft protective cover is provided outside the crankshaft. The rotating shaft radius of the fixed rotating shaft is larger than that of the movable rotating shaft. The movable rotating shaft rotates in a fixed circular motion around the fixed rotating shaft.

7. The device according to claim 1, characterized in that The inclinometer is one of a mechanical compass, a laser compass and a fiber optic compass; the displacement recorder is a gear recorder that can be engaged with the external thread on the hammer rod.

8. A method for detecting underwater foundation bearing capacity and identifying rock and soil properties based on the device according to any one of claims 1 to 7, characterized in that The specific steps include: S1: Transport the test vessel carrying the detection and identification device to the designated detection point in the designated waters and anchor the vessel; S2: putting the above detection and identification device into water, and adjusting the adjustment component according to the tilt data measured by the inclinometer to keep the device vertically fixed; S3: Start the onboard air compressor to supply air to the power cylinder, driving the heavy hammer to move up or down along the hammer rod; S4: Analyze and identify the geotechnical properties and estimated bearing capacity of the underwater foundation through the process values ​​recorded by the revolution recorder and displacement recorder.

9. The method according to claim 8, characterized in that The process steps of the power cylinder driving the weight to lift and lower in step S3 are as follows: S301: The power cylinder drives the connecting rod downward, causing the movable shaft to rotate in a circle around the fixed shaft; S302: The movable shaft rotates from top to bottom, driving the weight lock to penetrate the weight and clamp and fix it; S303: When the movable shaft moves from bottom to top, the heavy hammer lock drives the heavy hammer to lift up, and the heavy hammer is released. The steel wire rope with fixed spacing drives the self-locking pad to move upward along the hammer rod; S304: When the weight lock is lifted to the jack, the jack penetrates the weight lock, and the weight lock is unlocked and falls. S305: The heavy hammer falls and strikes the self-locking pad, driving the hammer rod locked in the downward direction with the self-locking pad to penetrate the formation; S306: The revolution recorder records the number of revolutions of the fixed shaft as the number of hammer strikes, and the displacement recorder records the displacement of the hammer rod with the fixed shaft as the depth of penetration into the formation.

10. The method according to claim 1, characterized in that The specific steps of analyzing the data in step S4 are: S401: Calculate fixed formation penetration △L n and the corresponding hammer number N n ; S402: Calculate the number of hammer blows N corresponding to the fixed penetration L by difference, and estimate the characteristic value of the bearing capacity of the soil layer; S403: Correct the standard value of the number of hammer blows N' based on the test of the bearing capacity of underwater foundation in the same classification of soil layer; S404: Correct the resistance values ​​due to the hammer rod length, the buoyancy of the hammer, and the hammer in water, draw an analysis curve, and identify the bearing capacity and estimated bearing capacity of the underwater foundation rock and soil properties.

Images