Floating platform method for construction control of large-diameter rock-socketed bored pile in deep water abrupt slope bare rock

Abstract

The application provides a floating platform method construction control method for a deep water steep slope bare rock large-diameter rock-embedded cast-in-place pile, and belongs to the technical field of construction control, which comprises the following steps: step 1, constructing a floating platform eight-cable positioning system for deep water steep slope bare rock large-diameter rock-embedded cast-in-place pile construction; step 2, performing a steep slope bare rock hole opening and grading drilling process for deep water steep slope bare rock large-diameter rock-embedded cast-in-place pile construction; step 3, performing ring wall rock-embedded concrete pouring control for deep water steep slope bare rock large-diameter rock-embedded cast-in-place pile construction; and step 4, performing whole-process quality detection for deep water steep slope bare rock large-diameter rock-embedded cast-in-place pile construction. The application solves the problems of difficult floating platform positioning, difficult steep slope hole opening, low drilling efficiency of large-diameter high-strength rock stratum and difficult rock-embedded construction quality control, and realizes quality improvement and efficiency increase, cost reduction and energy saving.

Description

Technical Field

[0001] This invention belongs to the field of construction control technology, specifically relating to a floating platform method for construction control of large-diameter rock-socketed cast-in-place piles in deep water, steep slopes, and bare rock. Background Technology

[0002] In infrastructure projects such as docks and bridges, the construction of large-diameter rock-socketed piles under deep-water, steep-slope, and bare-rock geological conditions has always been a challenge in the industry. The conventional "steel platform + impact drill" process has significant limitations. When the riverbed cover is thin or nonexistent, or the bank slope exceeds 30°, additional measures such as backfilling with bagged aggregate or setting up caissons are required to stabilize the steel platform, which not only increases construction costs by more than 30% but also extends the construction period. If the bank slope exceeds 45°, the difficulty of erecting the steel platform increases dramatically, and it may even be impossible to do so. Furthermore, the impact drill requires prior slope treatment, which presents problems such as high treatment difficulty, high cost, and significant environmental disturbance.

[0003] Taking the construction of an anchorage for a navigable vessel as an example, this project is located upstream of a dam and faces harsh conditions such as deep water (100-150m deep), large water level fluctuations (total water level difference of 30m, daily fluctuation of 2-3m / d during the rainy season), steep slopes (35-70°), and bare rock (moderately weathered silty sandstone with a strength of 92.0MPa, and a maximum of 190.2MPa), making conventional construction methods completely unsuitable. Furthermore, the 144 rock-socketed cast-in-place piles in the project are characterized by large pile diameter (2.3m), deep rock embedment (9-16m), and dispersed pile foundations (8 anchorages independently distributed, with a pier spacing of 28.4m), further increasing the construction difficulty. A new construction control method is urgently needed to solve these problems. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a floating platform method for construction control of large-diameter rock-embedded cast-in-place piles in deep water, steep slopes, and bare rock. This method solves problems such as difficulty in positioning the floating platform, difficulty in drilling on steep slopes, low drilling efficiency in large-diameter, high-strength rock strata, and difficulty in controlling the quality of rock-embedded construction, thereby improving quality and efficiency, reducing costs, and saving energy.

[0005] The present invention employs the following technical solution.

[0006] A floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep-water, steep-slope exposed rock, comprising:

[0007] Step 1: Construct an eight-cable positioning system for a floating platform used for the construction of large-diameter rock-socketed piles in deep water and steep slopes with exposed rock.

[0008] Step 2: Implement the steep slope bare rock drilling and staged drilling process for the construction of large-diameter rock-socketed cast-in-place piles in deep water and steep slopes;

[0009] Step 3: Implement ring wall rock-socketed concrete pouring control for the construction of large-diameter rock-socketed cast-in-place piles in deep water and steep slope bare rock;

[0010] Step 4: Conduct full-process quality inspection for the construction of large-diameter rock-socketed cast-in-place piles in deep water, steep slopes, and bare rock.

[0011] Furthermore, step 1 specifically includes:

[0012] Four positioning cables arranged in a figure-eight pattern are combined with four core-pulling cables arranged perpendicular to the floating platform used for the construction of large-diameter rock-socketed piles in deep-water steep slope bare rock. The anchor cable on the bank where the large-diameter rock-socketed piles in deep-water steep slope bare rock is located is connected to the pre-set anchor rod and anchored on the river side where the large-diameter rock-socketed piles in deep-water steep slope bare rock are located. Through real-time GPS monitoring and anchor pull adjustment, the planar positioning deviation is ≤2cm, which can adapt to water level changes of 30m and resist the maximum drilling torque of 1000kN·m of rotary drilling rig.

[0013] Furthermore, in step 1, the method for achieving a planar positioning deviation of ≤2cm, adapting to water level changes of 30m, and resisting the maximum drilling torque of 1000kN·m of the rotary drilling rig through real-time GPS monitoring and anchor pull adjustment includes:

[0014] Step 1-1: Configure the hardware for real-time GPS monitoring and anchor winch tension adjustment;

[0015] Steps 1-2: Perform monitoring via GPS positioning module;

[0016] Steps 1-3: Perform adaptive water level adjustment;

[0017] Steps 1-4: Implement anti-drilling rig torque stabilization control.

[0018] Furthermore, in step 1-1, the hardware used for real-time GPS monitoring and anchor winch tension adjustment includes:

[0019] GPS positioning module: Three R8 / R7 GPS receivers are selected and deployed at the front end, rear end and top of the control console of the floating platform to build a three-dimensional coordinate monitoring system. The sampling frequency is set to 1Hz to transmit the plane coordinates and elevation data of the floating platform in real time.

[0020] Anchor winch tension monitoring module: Tension sensors are installed on the winches of 8 anchor winches to collect anchor cable tension data in real time, with a sampling frequency of 0.5Hz;

[0021] Automatic control module: Equipped with MOXAA52 data converter and floating platform positioning control software, it receives GPS coordinate data and tension sensor data. When the coordinate deviation exceeds 2cm or the tension exceeds the set range, it automatically triggers the anchor winch to start and stop, and adjusts the anchor cable length and tension.

[0022] Furthermore, steps 1-2 include:

[0023] Using the design pile center as the reference coordinate (X0, Y0), GPS collects the real-time coordinates of the floating platform borehole center (Xt, Yt), calculates the plane deviation values ​​ΔX=|Xt-X0| and ΔY=|Yt-Y0|, and starts anchor adjustment when ΔX or ΔY>2cm;

[0024] The anchor cable tension is set within a safe range. When the tension sensor detects that the tension exceeds the set upper limit, the anchor winch loosens the cable; when the tension sensor detects that the tension is below the set lower limit, the anchor winch tightens the cable to ensure that the anchor cable is always under stable tension.

[0025] Furthermore, steps 1-3 include:

[0026] When the water level in the reservoir changes, the elevation data collected by the GPS positioning module is adjusted in conjunction with the anchor winch tension. The adjustment process is as follows:

[0027] GPS monitors the elevation change ΔZ of the floating platform. When ΔZ > 0.5m, the control console issues a command to tighten the cables of the river-side anchor winch and loosen the cables of the shore-side anchor winch, and simultaneously adjust the elevation of the floating platform to ensure that the center of the borehole is vertically aligned with the center of the pile position.

[0028] When the water level drops, the anchor winch is adjusted in the opposite direction, and the tension sensor provides real-time feedback on the cable tension to prevent the anchor cable from becoming too loose or too tight due to the drop in water level.

[0029] During the adjustment process, the GPS positioning module dynamically corrects the plane coordinates to ensure that ΔX and ΔY are always ≤2cm, thus achieving closed-loop control of "water level change - anchor cable adjustment - coordinate correction".

[0030] Furthermore, steps 1-4 include:

[0031] When the rotary drilling rig generates a torque of 1000 kN·m during drilling, the torque is directly resisted by four core-pulling cables, and the rotation of the floating platform is limited by the positioning cable. The specific control is as follows:

[0032] When torque is generated, the floating platform tends to rotate around the center of the borehole. The tension of the core-pulling cable increases instantaneously, the tension sensor triggers an early warning, and the anchor winch immediately tightens the core-pulling cable on the corresponding side while simultaneously loosening the cable on the opposite side to counteract the rotational torque.

[0033] Combined with GPS planar coordinate monitoring, if a rotational deviation of ΔX or ΔY exceeds 1cm, the positioning cable is adjusted synchronously to ensure that the floating platform only changes with the water level vertically and does not rotate horizontally, and the verticality of the borehole is controlled within 1%.

[0034] Furthermore, step 2 includes:

[0035] Construct a guide and positioning drill barrel, that is, add a spiral drill rod at the bottom of the drill barrel and a cross-shaped cutting tooth drill bit at the head of the drill rod to achieve direct drilling on steep slopes within 45°; when the slope exceeds 60°, the step method is used to drill in two stages. First, drill the first step to pre-treat the rock surface, and then drill the second step to ensure the drilling position and verticality.

[0036] Drilling is performed according to rock strength classification: low-strength mudstone is drilled in 2-3 passes, and high-strength fine sandstone is drilled in 4-5 passes.

[0037] Furthermore, step 3 includes:

[0038] The eccentric hopper is designed, and C35 ultra-retarded concrete is poured only in the annular gap between the steel casing and the rock-embedded hole. The initial pouring volume is calculated as follows: Calculate, where V is the initial irrigation volume; The diameter of the rock-embedded hole, H is the diameter of the steel casing; h is the burial depth of the guide pipe; h is the distance between the guide pipe and the bottom of the hole; t is the thickness of the sediment; d is the inner diameter of the guide pipe; and L is the total length of the guide pipe.

[0039] Furthermore, step 4 includes:

[0040] Hole forming stage: An intelligent ultrasonic hole forming detector is used to detect the hole diameter, hole depth, and verticality.

[0041] After pouring: the integrity of the pile body was verified by ultrasonic non-destructive testing and core drilling.

[0042] Furthermore, in step 4, the method for verifying the integrity of the pile body through ultrasonic non-destructive testing and core drilling includes:

[0043] Step 4-1: Preparations before testing, including the installation of sonic logging pipes and equipment selection;

[0044] Step 4-2: Perform the on-site testing procedure;

[0045] Step 4-3: Perform pile integrity assessment.

[0046] Furthermore, in step 4-1, the installation of sonic logging pipes includes: symmetrically installing 4 sonic logging pipes along the inner side of the reinforcing cage for each pile, with a spacing of ≤2m between the sonic logging pipes, the bottom closed and the top covered, and the inside of the sonic logging pipes filled with clean water; the sonic logging pipes must be firmly fixed to the reinforcing cage, with a verticality deviation of ≤1%, and the pipe openings must be at least 100mm above the top of the pile.

[0047] Equipment selection includes: choosing an intelligent ultrasonic testing instrument equipped with a cylindrical radial transducer; and determining the instrument system delay time using a calibration method before testing. .

[0048] Furthermore, step 4-2 includes:

[0049] Flat-surface measurement method: Place the transmitting and receiving transducers into two acoustic logging tubes respectively, and raise them synchronously at the same depth, with a raising speed ≤0.5m / s and a spacing of ≤100mm between the acoustic logging lines; record the first wave time of each acoustic logging line in real time. ,amplitude With main frequency ;

[0050] Data correction calculation: The original data is corrected to obtain the effective sound time and sound speed. The corresponding calculation formulas are as follows:

[0051] Effective time ,in For the first Effective acoustic time of a single acoustic measurement line; These are measurements taken during sound exposure. For instrument system delay time; This is the acoustic timing correction value between the acoustic logging tube and the coupled water layer;

[0052] Speed ​​of sound ,in For the first The sound path of a single sound measurement line;

[0053] amplitude ,in For the first The first peak value of the acoustic measurement line, The reference amplitude is zero dB.

[0054] Anomaly detection: Set a threshold for detecting sound speed anomalies. With amplitude critical value ,when ≤ or < At that time, it was determined to be an abnormal acoustic measurement line;

[0055] Fan-shaped scanning is used to detect abnormal areas to determine the location and extent of defects.

[0056] Furthermore, step 4-3 includes:

[0057] Based on the anomalies and defect range of the acoustic measurement line, the integrity category is determined according to the following criteria:

[0058] Class I piles: All acoustic parameters of the acoustic survey lines are normal, the received waveforms are normal, and there are no defects;

[0059] Class II piles: Slightly abnormal sonic logging lines are present, discontinuously distributed longitudinally, and accounting for less than 50% laterally;

[0060] Class III piles: Exhibit obvious abnormal acoustic logging lines, continuously distributed longitudinally or accounting for ≥50% laterally;

[0061] Class IV piles: There are severely abnormal acoustic test lines, or the defect range exceeds 50% of the pile cross-section.

[0062] The beneficial effects of the present invention are as follows, compared with the prior art:

[0063] Economic benefits: The 144 pile foundations saved 5,902 m³ of concrete and 1,472 m of drilling work, reducing costs by 4.72 million yuan. Construction efficiency was improved by 60% compared to conventional processes, and the cost of secondary entry and exit of ship and machinery equipment was reduced by 50%.

[0064] Social benefits: Saves 100.8 tons of standard coal, reduces carbon dioxide emissions by 251.4 tons, reduces drilling slag emissions by 1,600 cubic meters, and achieves green construction; after the anchorage is completed, it can accommodate 28 5,000-ton hazardous chemical vessels, alleviating lock congestion.

[0065] Technical value: It provides technical support for similar deep-water, steep-slope, bare-rock engineering projects, and its widespread application can reduce the cost of similar projects by 20-30%. Attached Figure Description

[0066] Figure 1 This is a flowchart of the floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep water, steep slopes, and bare rock in this invention. Detailed Implementation

[0067] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of this invention. The embodiments described in this application are merely some embodiments of this invention, and not all embodiments. Based on the spirit of this invention, other embodiments obtained by those skilled in the art without creative effort are all within the protection scope of this invention.

[0068] like Figure 1 As shown, a floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep-water, steep-slope bare rock includes:

[0069] Step 1: Construct an eight-cable positioning system for a floating platform used for the construction of large-diameter rock-socketed piles in deep water and steep slopes with exposed rock.

[0070] In a preferred but non-limiting embodiment of the present invention, step 1 specifically includes:

[0071] Four positioning cables arranged in a figure-eight pattern are combined with four core-pulling cables arranged perpendicular to the floating platform used for the construction of large-diameter rock-socketed piles in deep-water steep slope bare rock. The anchor cable on the bank where the large-diameter rock-socketed piles in deep-water steep slope bare rock is located is connected to the pre-set anchor rod and anchored on the river side where the large-diameter rock-socketed piles in deep-water steep slope bare rock are located. Through real-time GPS monitoring and anchor pull adjustment, the planar positioning deviation is ≤2cm, which can adapt to water level changes of 30m and resist the maximum drilling torque of 1000kN·m of rotary drilling rig.

[0072] In a preferred but non-limiting embodiment of the present invention, in step 1, a method is used to achieve a planar positioning deviation of ≤2cm, adapt to water level changes of 30m, and resist the maximum drilling torque of 1000kN·m of a rotary drilling rig, through real-time GPS monitoring and anchor pull adjustment. This method includes:

[0073] This method achieves high-precision positioning, adaptive water level adjustment, and torque stability of the floating platform in deep water and steep slope environments by combining GPS positioning monitoring with closed-loop adjustment of anchor winch tension and mechanical calculation of the anchor cable system. The core of the method includes three parts: monitoring system construction, tension calculation and adjustment, and adaptive water level control.

[0074] Step 1-1: Configure the hardware for real-time GPS monitoring and anchor winch tension adjustment;

[0075] In a preferred but non-limiting embodiment of the present invention, in step 1-1, the hardware for real-time GPS monitoring and anchor winch tension adjustment includes:

[0076] GPS positioning module: Three Trimble R8 / R7 GPS receivers (static horizontal accuracy 3mm±0.1ppm, dynamic horizontal accuracy 8mm±1ppm) are selected and deployed at the front end (river side), rear end (shore side) and top of the control console of the floating platform to build a three-dimensional coordinate monitoring system. The sampling frequency is set to 1Hz to transmit the planar coordinates (X, Y axes) and elevation (Z axis) data of the floating platform in real time.

[0077] Anchor winch tension monitoring module: Tension sensors (range 0-200kN, accuracy ±1%) are installed on the winches of 8 anchor winches (4 positioning anchor winches of 15t class and 4 core-pulling anchor winches of 10t class) to collect anchor cable tension data in real time at a sampling frequency of 0.5Hz.

[0078] Automatic control module: Equipped with MOXAA52 data converter and floating platform positioning control software, it receives GPS coordinate data and tension sensor data. When the coordinate deviation exceeds 2cm or the tension exceeds the set range, it automatically triggers the anchor winch to start and stop, and adjusts the anchor cable length and tension.

[0079] Steps 1-2: Perform monitoring via GPS positioning module;

[0080] In a preferred but non-limiting embodiment of the present invention, steps 1-2 include:

[0081] Using the design pile center as the reference coordinate (X0, Y0), GPS collects the real-time coordinates of the floating platform borehole center (Xt, Yt), calculates the plane deviation values ​​ΔX=|Xt-X0| and ΔY=|Yt-Y0|, and starts anchor adjustment when ΔX or ΔY>2cm;

[0082] The anchor cable tension is set within a safe range (design tension value ±10%). When the tension sensor detects that the tension exceeds the set upper limit, the anchor winch loosens the cable; when the tension sensor detects that the tension is below the set lower limit, the anchor winch tightens the cable to ensure that the anchor cable is always under stable stress.

[0083] Steps 1-3: Perform adaptive water level adjustment;

[0084] In a preferred but non-limiting embodiment of the present invention, steps 1-3 include:

[0085] When the reservoir water level changes (maximum 30m), the elevation data (Z-axis) collected by the GPS positioning module is used to coordinate the adjustment with the anchor winch tension. The adjustment process is as follows:

[0086] GPS monitors the elevation change ΔZ of the floating platform. When ΔZ > 0.5m (water level rise), the control console issues a command to tighten the cables of the river-side anchor winch and loosen the cables of the shore-side anchor winch, and simultaneously adjust the elevation of the floating platform to ensure that the center of the borehole is vertically aligned with the center of the pile position.

[0087] When the water level drops, the anchor winch is adjusted in the opposite direction (tightening on the bank side and loosening on the river side). At the same time, the tension sensor provides real-time feedback on the cable tension to prevent the anchor cable from becoming loose (tension below the lower limit) or too tight (tension exceeding the upper limit) due to the drop in water level.

[0088] During the adjustment process, the GPS positioning module dynamically corrects the plane coordinates to ensure that ΔX and ΔY are always ≤2cm, thus achieving closed-loop control of "water level change - anchor cable adjustment - coordinate correction".

[0089] Steps 1-4: Implement anti-drilling rig torque stabilization control.

[0090] In a preferred but non-limiting embodiment of the present invention, steps 1-4 include:

[0091] When the rotary drilling rig generates a torque of 1000 kN·m, the torque is directly resisted by four core-pulling cables (arranged perpendicular to the ship's side), and the rotation of the floating platform is limited by positioning cables. The specific control is as follows:

[0092] When torque is generated, the floating platform tends to rotate around the center of the borehole, and the tension of the core-pulling cable increases instantaneously. The tension sensor triggers an early warning (exceeding the upper limit of 564kN). The anchor winch immediately tightens the core-pulling cable on the corresponding side and simultaneously loosens the cable on the opposite side to counteract the rotational torque.

[0093] Combined with GPS planar coordinate monitoring, if a rotational deviation of ΔX or ΔY exceeds 1cm, the positioning cable is adjusted synchronously to ensure that the floating platform only changes with the water level vertically and does not rotate horizontally, and the verticality of the borehole is controlled within 1%.

[0094] Step 2: Implement the steep slope bare rock drilling and staged drilling process for the construction of large-diameter rock-socketed cast-in-place piles in deep water and steep slopes;

[0095] In a preferred but non-limiting embodiment of the present invention, step 2 includes:

[0096] The development of a guide and positioning drill barrel involves adding a spiral drill rod (219mm in diameter and 4.1m in length) to the bottom of the drill barrel and a cross-shaped cutting drill bit at the head of the drill rod, enabling direct drilling on steep slopes of up to 45°. When the slope exceeds 60°, a step method is used to drill in two stages: first, a first-stage step is drilled to pre-treat the rock surface, and then a second-stage step is drilled to ensure the drilling position and verticality.

[0097] Drilling is performed according to rock strength classification: low-strength mudstone (≤30MPa) is drilled in 2-3 passes, and high-strength fine sandstone (≥60MPa) is drilled in 4-5 passes. For example, a 2.9m pile hole is constructed in stages of 1.5m→2.1m→2.55m→2.9m, using a rotary cutter drill barrel (including a crushing guide wing and a slag collection sleeve), which increases drilling efficiency by more than 50% compared to a roller cone drill barrel.

[0098] Step 3: Implement ring wall rock-socketed concrete pouring control for the construction of large-diameter rock-socketed cast-in-place piles in deep water and steep slope bare rock;

[0099] In a preferred but non-limiting embodiment of the present invention, step 3 includes:

[0100] The design incorporates an eccentric hopper (3.2m³ volume, 220mm outlet diameter). C35 ultra-retarded concrete is poured only in the annular gap (300mm wide) between the steel casing (2.3m diameter) and the rock-embedded hole (2.9m diameter). The initial pouring volume is calculated as follows: Calculations were performed to ensure that the initial setting time of the concrete is ≥6h, the compactness is ≥98%, and the amount of concrete used is reduced by about 40%, where V is the initial pouring volume (m³). The diameter of the rock-embedded hole is 2.9 m. H is the diameter of the steel casing (m, 2.3m); H is the burial depth of the guide pipe (m, 0.8m); h is the distance from the bottom of the hole to the guide pipe (m, 0.3m); t is the thickness of the sediment (m, 0); d is the inner diameter of the guide pipe (m, 0.21m); and L is the total length of the guide pipe (m, 57m).

[0101] Technical benefits of initial pouring volume: The initial pouring volume is precisely controlled at 3.0m³, ensuring that the tremie pipe is buried at a depth of ≥0.8m, avoiding pile breakage, and achieving a 98% compactness of the ring wall concrete. Compared with traditional full-hole pouring, it saves 5902m³ of concrete and reduces costs by 4.72 million yuan.

[0102] Step 4: Conduct full-process quality inspection for the construction of large-diameter rock-socketed cast-in-place piles in deep water, steep slopes, and bare rock.

[0103] In a preferred but non-limiting embodiment of the present invention, step 4 includes:

[0104] Hole forming stage: Use an intelligent ultrasonic hole forming detector to detect the hole diameter (deviation ≤50mm), hole depth (deviation ≤100mm), and verticality (≤1%).

[0105] After pouring: The integrity of the pile body was verified by ultrasonic non-destructive testing (sonic logging tube spacing ≤ 2m) and core drilling (5 cores / 144 cores).

[0106] In a preferred but non-limiting embodiment of the present invention, step 4, the method for verifying the integrity of the pile body by ultrasonic non-destructive testing (sonic logging tube spacing ≤ 2m) and core drilling (5 cores / 144 cores), includes:

[0107] This method combines ultrasonic non-destructive testing with core drilling for precise verification, enabling dual control over the integrity of large-diameter rock-socketed cast-in-place piles in deep water, steep slopes, and bare rock. It ensures both testing efficiency and accurate results. The core of this method includes three parts: ultrasonic testing procedures, core drilling operation specifications, and result judgment criteria.

[0108] I. Ultrasonic Non-destructive Testing Method (sonic logging tube spacing ≤ 2m)

[0109] Ultrasonic testing is based on the principle of the difference in propagation speed and amplitude of sound waves in intact and defective concrete. Sound waves are transmitted through a sonic logging tube, and the reflected signals are received to analyze the internal quality of the pile. It is suitable for 100% full coverage testing of 144 piles.

[0110] Step 4-1: Preparations before testing, including the installation of sonic logging pipes and equipment selection;

[0111] In a preferred but non-limiting embodiment of the present invention, in step 4-1, the sonic logging pipe installation includes: symmetrically installing 4 sonic logging pipes (Φ57mm×3mm steel pipes) along the inner side of the reinforcing cage for each pile (diameter 2.3m), with a spacing of ≤2m between the sonic logging pipes, a closed bottom and a capped top, and filling the pipes with clean water; the sonic logging pipes must be firmly fixed to the reinforcing cage, with a verticality deviation of ≤1%, and the pipe opening must be at least 100mm above the top of the pile to avoid displacement or blockage during pouring;

[0112] Equipment selection includes: using an intelligent ultrasonic detector (sampling time interval ≤ 0.5μs, dynamic range ≥ 100dB), equipped with a cylindrical radial transducer (resonant frequency 30-60kHz, watertightness 1MPa, no water leakage), and determining the instrument system delay time using a calibration method before testing. (Usually ≤5μs).

[0113] Step 4-2: Perform the on-site testing procedure;

[0114] In a preferred but non-limiting embodiment of the present invention, step 4-2 includes:

[0115] Flat-surface measurement method: Place the transmitting and receiving transducers into two acoustic logging tubes respectively, and raise them synchronously at the same depth, with a raising speed ≤0.5m / s and a spacing of ≤100mm between the acoustic logging lines; record the first wave time of each acoustic logging line in real time. ,amplitude With main frequency ;

[0116] Data correction calculation: The original data is corrected to obtain the effective sound time and sound speed. The corresponding calculation formulas are as follows:

[0117] Effective time ,in For the first The effective acoustic time (μs) of each acoustic measurement line reflects the actual propagation time of sound waves in concrete. The measurement value for acoustic time (μs); The instrument system delay time (μs, determined through calibration tests; in this invention, it can be 3.2 μs). The acoustic time correction value for the acoustic logging tube and the coupled water layer (μs, 1.5μs for Φ57mm acoustic logging tube); Eliminating interference between the instrument and the acoustic tube ensures accurate acoustic timing data, providing a reliable basis for sound velocity calculation.

[0118] Speed ​​of sound ,in For the first The sound path of a single sound measurement line;

[0119] amplitude ,in For the first The first peak value of the acoustic measurement line, The reference amplitude is zero dB.

[0120] Anomaly detection: Set a threshold for detecting sound speed anomalies. With amplitude critical value ,when ≤ or < At that time, it was determined to be an abnormal acoustic measurement line;

[0121] For abnormal areas, a sector scan is used (the horizontal angle between the lines connecting the midpoints of the transducers is ≤40°) to determine the location and extent of the defects.

[0122] Step 4-3: Perform pile integrity assessment.

[0123] In a preferred but non-limiting embodiment of the present invention, step 4-3 includes:

[0124] Based on the anomalies and defect range of the acoustic measurement line, the integrity category is determined according to the following criteria:

[0125] Class I piles: All acoustic parameters of the acoustic survey lines are normal, the received waveforms are normal, and there are no defects;

[0126] Class II piles: Slightly abnormal sonic logging lines are present, discontinuously distributed longitudinally, and accounting for less than 50% laterally;

[0127] Class III piles: Exhibit obvious abnormal acoustic logging lines, continuously distributed longitudinally or accounting for ≥50% laterally;

[0128] Class IV piles: There are severely abnormal acoustic test lines (sound velocity is lower than the lower limit value (v_L)), or the defect range exceeds 50% of the pile cross section.

[0129] Taking anchorage #1 (slope 45-60°, lithology moderately weathered silty sandstone, strength 83.98MPa) of a certain anchorage construction project as an example, the specific implementation steps of this invention are as follows:

[0130] 1. Construction Preparation

[0131] Equipment selection: A 4000t roll-on / roll-off ship (105m long and 23m wide) is selected as the floating platform, equipped with a 550kN·m rotary drilling rig (maximum drilling diameter of 3m) and a 320t crawler crane (70m main boom, 18m lifting distance, rated lifting capacity of 77t).

[0132] Anchor bolt pre-installation: Drill holes in the weathered rock layer of the bank slope and insert Φ30mm threaded steel anchor bolts (anchoring depth ≥3m). Weld the anchor bolt heads with 3cm thick steel plates to form mooring points;

[0133] Drill tool preparation: Machining the guide and positioning drill barrel (outer diameter 2.85m, height 1.6m, spiral rib spacing 300mm) and the cutter drill barrel (3 sets of cutters, guide vane width 15cm).

[0134] 2. Floating platform positioning

[0135] Coarse positioning: Use GPS to move the floating platform to the upstream pier area of ​​anchor position #1, and place 4 figure-eight positioning anchors (attached to anchor rods on the shore side and anchored at a distance of 200m on the river side). Adjust the anchor cables to make the borehole center deviation ≤100mm.

[0136] Precise positioning: Four core-pulling cables (perpendicular to the ship's side, with a total cable length of 350m) are deployed. The anchor cables are finely adjusted to ensure that the plane deviation is ≤2cm by real-time monitoring through anchor winch tension sensors (range 0-200kN) and GPS, and all anchor cables are tightened.

[0137] 3. Slope opening and drilling

[0138] Rock surface treatment: Using a guide positioning drill barrel, the spiral drill rod is first drilled into the rock layer for 0.5m and fixed. Then, the outer wall of the drill barrel is driven to drill 0.5m. After the rock surface is divided, it is smoothed with a cross drill bit to form a drilling platform with a diameter of 2.9m.

[0139] Staged drilling: The first drilling uses a 1.5m rotary drill barrel. After drilling the core column, the debris is cleaned up using the guide vanes and the slag collection sleeve. The second drilling uses a 2.1m drill barrel, the third uses a 2.55m drill barrel, and the fourth uses a 2.9m drill barrel. The hole depth is checked with a measuring rope after each stage of drilling. Drilling is carried out to the designed rock embedment depth of 10m (hole bottom elevation 118.6m).

[0140] Hole formation inspection: The hole diameter was 2.9m (deviation +20mm), the hole depth was 10.05m (deviation +50mm), and the perpendicularity was 0.8%, which met the requirements.

[0141] 4. Steel casing installation and concrete pouring

[0142] Steel casing hoisting: A 57m long steel casing (weighing 65.3t) was selected and hoisted by a 320t crawler crane and a 150t floating crane. The casing was positioned by a guide frame (including resin rollers and jacks for fine adjustment). The verticality was monitored by a plumb line and was ≤0.5%. It was temporarily fixed with three wedge-shaped limit blocks (steel, triangular shape).

[0143] Concrete pouring: An eccentric hopper is used, and a Φ220mm guide pipe is inserted into the annular gap. The first pour is 3.2m³ of C35 concrete (slump 220mm), and subsequent pours are made continuously until the design elevation (+163m). The height difference of the top surface of the concrete is ≤0.3m when measured with a measuring rope.

[0144] Quality inspection: 7 days after pouring, 3 sonic logging tubes were installed on the outside of the steel casing, and no defects were found in the ultrasonic test; 28 days later, core samples were drilled and taken, and the core sample strength was 40.8 MPa, indicating good compactness.

[0145] 5. Underwater cast-in-place pile construction

[0146] Installation of telescopic casing: The top of the steel casing is 6m above the water surface. Install a 15m telescopic casing (inner casing Φ2300mm, outer casing Φ2380mm) and extend it to 1m above the water surface.

[0147] Reinforcing cage installation: Hang the reinforcing cage (32.8m long) on ​​the top of the expansion sleeve by extending the main bars, ensuring that the protective layer thickness is ≥70mm;

[0148] Concrete pouring: Pour C30 underwater concrete to the design elevation +164m, with an over-pouring of 1m. After final setting, remove the expansion sleeve and chisel away the over-pouring portion after the water level drops.

[0149] The beneficial effects of the present invention are as follows, compared with the prior art:

[0150] Economic benefits: The 144 pile foundations saved 5,902 m³ of concrete and 1,472 m of drilling work, reducing costs by 4.72 million yuan. Construction efficiency was improved by 60% compared to conventional processes, and the cost of secondary entry and exit of ship and machinery equipment was reduced by 50%.

[0151] Social benefits: Saves 100.8 tons of standard coal, reduces carbon dioxide emissions by 251.4 tons, reduces drilling slag emissions by 1,600 cubic meters, and achieves green construction; after the anchorage is completed, it can accommodate 28 5,000-ton hazardous chemical vessels, alleviating lock congestion.

[0152] Technical value: It provides technical support for similar deep-water, steep-slope, bare-rock engineering projects, and its widespread application can reduce the cost of similar projects by 20-30%.

[0153] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention without departing from the spirit and scope of the present invention. Any modifications or equivalent substitutions should be covered within the scope of protection of the claims of the present invention.

Claims

1. A floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep-water, steep-slope bare rock, characterized in that... include: Step 1: Construct an eight-cable positioning system for a floating platform used for the construction of large-diameter rock-socketed piles in deep water and steep slopes with exposed rock. Step 2: Implement the steep slope bare rock drilling and staged drilling process for the construction of large-diameter rock-socketed cast-in-place piles in deep water and steep slopes; Step 3: Implement ring wall rock-socketed concrete pouring control for the construction of large-diameter rock-socketed cast-in-place piles in deep water and steep slope bare rock; Step 4: Conduct full-process quality inspection for the construction of large-diameter rock-socketed cast-in-place piles in deep water and steep slope bare rock; Step 1 specifically includes: Four positioning cables arranged in a figure-eight pattern are combined with four core-pulling cables arranged perpendicular to the floating platform used for the construction of large-diameter rock-socketed piles in deep-water steep slope bare rock. The anchor cable on the bank where the large-diameter rock-socketed piles in deep-water steep slope bare rock is located is connected to the pre-set anchor rod and anchored on the river side where the large-diameter rock-socketed piles in deep-water steep slope bare rock are located. Through real-time GPS monitoring and anchor pull adjustment, the planar positioning deviation is ≤2cm, which can adapt to water level changes of 30m and resist the maximum drilling torque of 1000kN·m of rotary drilling rig. In step 1, a method is used to achieve a planar positioning deviation of ≤2cm, adapt to water level changes of 30m, and withstand the maximum drilling torque of 1000kN·m of rotary drilling rigs through real-time GPS monitoring and anchor pull adjustment. This method includes: Step 1-1: Configure the hardware for real-time GPS monitoring and anchor winch tension adjustment; Steps 1-2: Perform monitoring via GPS positioning module; Steps 1-3: Perform adaptive water level adjustment; Steps 1-4: Implement anti-drilling rig torque stabilization control; In step 1-1, the hardware used for real-time GPS monitoring and anchor winch tension adjustment includes: GPS positioning module: Three R8 / R7 GPS receivers are selected and deployed at the front end, rear end and top of the control console of the floating platform to build a three-dimensional coordinate monitoring system. The sampling frequency is set to 1Hz to transmit the plane coordinates and elevation data of the floating platform in real time. Anchor winch tension monitoring module: Tension sensors are installed on the winches of 8 anchor winches to collect anchor cable tension data in real time, with a sampling frequency of 0.5Hz; Automatic control module: Equipped with MOXAA52 data converter and floating platform positioning control software, it receives GPS coordinate data and tension sensor data. When the coordinate deviation exceeds 2cm or the tension exceeds the set range, it automatically triggers the anchor winch to start and stop, and adjusts the anchor cable length and tension. Steps 1-2 include: Using the design pile center as the reference coordinate (X0, Y0), GPS collects the real-time coordinates of the floating platform borehole center (Xt, Yt), calculates the plane deviation values ​​ΔX=|Xt-X0| and ΔY=|Yt-Y0|, and starts anchor adjustment when ΔX or ΔY>2cm; The anchor cable tension is set within a safe range. When the tension sensor detects that the tension exceeds the set upper limit, the anchor winch loosens the cable; when the tension sensor detects that the tension is below the set lower limit, the anchor winch tightens the cable to ensure that the anchor cable is always under stable tension. Steps 1-3 include: When the water level in the reservoir changes, the elevation data collected by the GPS positioning module is adjusted in conjunction with the anchor winch tension. The adjustment process is as follows: GPS monitors the elevation change ΔZ of the floating platform. When ΔZ > 0.5m, the control console issues a command to tighten the cables of the river-side anchor winch and loosen the cables of the shore-side anchor winch, and simultaneously adjust the elevation of the floating platform to ensure that the center of the borehole is vertically aligned with the center of the pile position. When the water level drops, the anchor winch is adjusted in the opposite direction, and the tension sensor provides real-time feedback on the cable tension to prevent the anchor cable from becoming too loose or too tight due to the drop in water level. During the adjustment process, the GPS positioning module dynamically corrects the plane coordinates to ensure that ΔX and ΔY are always ≤2cm, thus achieving closed-loop control of "water level change - anchor cable adjustment - coordinate correction". Steps 1-4 include: When the rotary drilling rig generates a torque of 1000 kN·m during drilling, the torque is directly resisted by four core-pulling cables, and the rotation of the floating platform is limited by the positioning cable. The specific control is as follows: When torque is generated, the floating platform tends to rotate around the center of the borehole. The tension of the core-pulling cable increases instantaneously, the tension sensor triggers an early warning, and the anchor winch immediately tightens the core-pulling cable on the corresponding side while simultaneously loosening the cable on the opposite side to counteract the rotational torque. Combined with GPS planar coordinate monitoring, if a rotational deviation of ΔX or ΔY exceeds 1cm, the positioning cable is adjusted synchronously to ensure that the floating platform only changes with the water level vertically and does not rotate horizontally, and the verticality of the borehole is controlled within 1%.

2. The floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep-water steep-slope bare rock as described in claim 1, characterized in that, Step 2 includes: Construct a guide and positioning drill barrel, that is, add a spiral drill rod at the bottom of the drill barrel and a cross-shaped cutting tooth drill bit at the head of the drill rod to achieve direct drilling on steep slopes within 45°; when the slope exceeds 60°, the step method is used to drill in two stages. First, drill the first step to pre-treat the rock surface, and then drill the second step to ensure the drilling position and verticality. Drilling is performed according to rock strength classification: low-strength mudstone is drilled in 2-3 passes, and high-strength fine sandstone is drilled in 4-5 passes.

3. The floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep-water steep-slope bare rock as described in claim 2, is characterized in that... Step 3 includes: The eccentric hopper is designed, and C35 ultra-retarded concrete is poured only in the annular gap between the steel casing and the rock-embedded hole. The initial pouring volume is calculated as follows: Calculate, where V is the initial irrigation volume; The diameter of the rock-embedded hole, H is the diameter of the steel casing; h is the burial depth of the guide pipe; h is the distance between the guide pipe and the bottom of the hole; t is the thickness of the sediment; d is the inner diameter of the guide pipe; and L is the total length of the guide pipe.

4. The floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep-water steep-slope bare rock as described in claim 3, is characterized in that... Step 4 includes: Hole forming stage: An intelligent ultrasonic hole forming detector is used to detect the hole diameter, hole depth, and verticality. After pouring: the integrity of the pile body was verified by ultrasonic non-destructive testing and core drilling.

5. The floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep-water steep slope bare rock according to claim 4, characterized in that, In step 4, the method for verifying the integrity of the pile body through ultrasonic non-destructive testing and core drilling includes: Step 4-1: Preparations before testing, including the installation of sonic logging pipes and equipment selection; Step 4-2: Perform the on-site testing procedure; Step 4-3: Perform pile integrity assessment.

6. The floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep-water steep slope bare rock as described in claim 5, is characterized in that... In step 4-1, the installation of sonic logging pipes includes: 4 sonic logging pipes are symmetrically installed along the inner side of the reinforcing cage for each pile, with a spacing of ≤2m between the sonic logging pipes, the bottom is closed and the top is covered, and the inside of the sonic logging pipes is filled with clean water; the sonic logging pipes must be firmly fixed to the reinforcing cage, with a verticality deviation of ≤1%, and the pipe opening is more than 100mm above the top of the pile. Equipment selection includes: choosing an intelligent ultrasonic testing instrument equipped with a cylindrical radial transducer; and determining the instrument system delay time using a calibration method before testing. .

7. The floating platform construction control method for large-diameter rock-socketed cast-in-place piles in deep-water steep-slope bare rock as described in claim 6, characterized in that, Step 4-2 includes: Flat-surface measurement method: Place the transmitting and receiving transducers into two acoustic logging tubes respectively, and raise them synchronously at the same depth, with a raising speed ≤0.5m / s and a spacing between the acoustic logging lines ≤100mm; record the first wave time of each acoustic logging line in real time. ,amplitude With main frequency ; Data correction calculation: The original data is corrected to obtain the effective sound time and sound speed. The corresponding calculation formulas are as follows: Effective time ,in For the first Effective acoustic time of a single acoustic measurement line; These are measurements taken during sound exposure. For instrument system delay time; This is the acoustic timing correction value between the acoustic logging tube and the coupled water layer; Speed ​​of sound ,in For the first The sound path of a single sound measurement line; amplitude ,in For the first The first peak value of the acoustic measurement line, The reference amplitude is zero dB. Anomaly detection: Set a threshold for detecting sound speed anomalies. With amplitude critical value ,when ≤ or < At that time, it was determined to be an abnormal acoustic measurement line; Fan-shaped scanning is used to determine the location and extent of defects in abnormal areas; Step 4-3 includes: Based on the anomalies and defect range of the acoustic measurement line, the integrity category is determined according to the following criteria: Class I piles: All acoustic parameters of the acoustic survey lines are normal, the received waveforms are normal, and there are no defects; Class II piles: Slightly abnormal sonic logging lines are present, discontinuously distributed longitudinally, and accounting for less than 50% laterally; Class III piles: Exhibit obvious abnormal acoustic logging lines, continuously distributed longitudinally or accounting for ≥50% laterally; Class IV piles: There are severely abnormal acoustic test lines, or the defect range exceeds 50% of the pile cross-section.

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