A full life cycle repair method for spillway scouring pits

Abstract

The invention discloses a full life cycle repair method for a spillway scouring pit, which specifically comprises the following steps: obtaining the surface and internal three-dimensional morphological characteristics of the spillway scouring pit and the material parameters of the base concrete, preliminarily determining the excavation range, the roughness of the base concrete and the repair mortar, comparing the material parameters of the repair mortar specimen with the obtained material parameters of the base concrete, optimizing the repair mortar, obtaining the interface stress distribution and interface displacement change curve between the repair mortar and the base concrete through a repair mortar-base concrete model, determining the final excavation range, the roughness of the base concrete and the repair mortar, laying out stress-strain sensors and strength sensors, obtaining the stress distribution and displacement change of the interface between the repair mortar and the base concrete during operation, obtaining the material parameters of the repair area, and performing cyclic optimization to obtain the excavation range, the roughness of the base concrete and the repair mortar of the spillway base concrete suitable for the full life cycle.

Description

Technical Field

[0001] The invention belongs to the technical field of repairing spillways of hydraulic structures, and relates to a full-life cycle repair method for spillway scouring pits. Background Art

[0002] Due to the complexity of operating conditions and working environment, the concrete interface of hydraulic structures generally suffers from aging, scouring and wear, which affects the safety of hydraulic structures. Among the damages to hydraulic structures, the damage to the spillway is the most common. Since the spillway is always scoured by the downstream water flow, especially the high-speed water flow, the damage caused by the scouring of the water flow can be seen everywhere and is difficult to avoid in itself and in the downstream river channel, and is sometimes even the main cause of dam failure. The repair of spillway scouring pits is related to the safe and stable operation of the dam.

[0003] Traditionally, the treatment of spillway scouring pits usually adopts mortar repair. After grinding the surface of the scouring pit, mortar is poured to make the mortar bond with the base concrete to achieve the purpose of repair. However, this traditional repair method can only solve the scouring problem in the short term and has the following disadvantages: (1) The design and construction are blind and empirical, which leads to the existing spillway scouring pit repair only treating the symptoms but not the root cause, resulting in the need for rework and repair several years after the construction period, and the spillway scouring pit treatment during the operation period; (2) The deep cracks in the spillway base concrete are not treated, and the repaired spillway still has great safety hazards; (3) After the repair of the spillway scouring pit, scouring damage will occur again every one or two years, resulting in the need for repeated repairs of the spillway, which consumes a lot of manpower and financial resources; (4) There is no plan for the full life cycle of the spillway, and it is impossible to know the condition of the repaired spillway during the construction and operation periods, and it is impossible to take preventive measures. Summary of the invention

[0004] The purpose of the present invention is to provide a full life cycle repair method for spillway scouring holes, which solves the problem that the existing scouring hole repair method cannot obtain the information of the repair area in real time and has high repair cost.

[0005] The technical solution adopted by the present invention is a full life cycle repair method for spillway scouring pits, which is specifically implemented according to the following steps:

[0006] Step 1: perform three-dimensional scanning on the concrete surface of the spillway to be tested and conduct comprehensive ultrasonic physical detection to obtain the surface and internal three-dimensional morphological characteristics of the spillway scouring pit and obtain the material parameters of the base concrete of the spillway to be tested;

[0007] Step 2, according to the material parameters of the base concrete obtained in step 1, determine the excavation range of the base concrete, the roughness of the base concrete and select the repair mortar;

[0008] Step 3, using the repair mortar selected in step 2 to prepare a repair mortar specimen, measuring the material parameters of the repair mortar specimen, and comparing the material parameters of the repair mortar specimen with the material parameters of the base concrete obtained in step 1 to obtain an optimized repair mortar;

[0009] Step 4, numerically simulate the repair area according to the excavation range of the spillway base concrete determined in step 2, the roughness of the base concrete and the repair mortar optimized in step 3, obtain the interface stress distribution curve and interface displacement change curve between the repair mortar and the base concrete, and determine the final excavation range of the spillway base concrete, the roughness of the base concrete, and the repair mortar;

[0010] Step 5, excavate according to the final excavation range of the base concrete, the roughness of the base concrete, and the repair mortar obtained in step 4, drill grouting holes in the deep cracks in the base concrete and inject the repair mortar, polish the surface of the flood channel pit, inject the repair mortar into the flood channel pit, and deploy stress-strain sensors and strength sensors;

[0011] Step 6, obtain the stress distribution and displacement change of the interface between the repair mortar and the base concrete during the construction period and the operation period through the stress-strain sensor and strength sensor deployed in step 5, and obtain the compressive strength, elastic modulus, density, Poisson's ratio, and linear expansion coefficient of the repair area. Repeat steps 2-4 to obtain the excavation range of the spillway base concrete, the roughness of the base concrete, and the repair mortar suitable for the entire life cycle.

[0012] The present invention is also characterized in that

[0013] In step 1, the material parameters of the spillway base concrete include the base concrete compressive strength, elastic modulus, density, Poisson's ratio, and linear expansion coefficient.

[0014] In step 2, the excavation range of the base concrete is determined by: obtaining the initial design compressive strength by consulting the original design data of the spillway, comparing the initial design compressive strength with the base concrete compressive strength obtained in step 1, and excavating the base concrete whose compressive strength is less than 70% of the initial design compressive strength to obtain the excavation range of the base concrete;

[0015] The roughness of the base concrete is 0.65 to 1.5 mm;

[0016] The repair mortar shall use epoxy or polyurethane mortar and its 28-day compressive strength after solidification shall not be less than the initial design compressive strength.

[0017] The specific process of step 3 is: use the repair mortar screened in step 2 to prepare a repair mortar specimen, measure the elastic modulus, density, Poisson's ratio and linear expansion coefficient of the repair mortar specimen, and compare the linear expansion coefficient of the repair mortar specimen with the linear expansion coefficient of the base concrete obtained in step 1. The difference between the two is no more than 10%, and the optimized repair mortar is obtained.

[0018] The specific process of step 4 is:

[0019] Step 4.1, using ABAQUS software to establish a repair mortar-base concrete model, the quantitative in the repair mortar-base concrete model is the elastic modulus, density, Poisson's ratio of the base concrete obtained in step 1 and the elastic modulus, density, Poisson's ratio of the repair mortar obtained in step 3; the variables in the repair mortar-base concrete model are the excavation range of the base concrete, the roughness of the base concrete and the optimized repair mortar; the output results are the interface stress distribution curve and the interface displacement change curve;

[0020] Step 4.2, according to the actual environment of the spillway, a load is applied to the repair mortar-base concrete model established in step 4.1 to simulate the scouring load of high-speed water flow, and obtain the stress distribution curve of the interface between the repair mortar and the base concrete and the displacement change curve of the interface between the repair mortar and the base concrete;

[0021] Step 4.3, based on the interface stress distribution curve and interface displacement change curve obtained in step 4.2, screen out the solutions that meet the requirements that the tensile stress at the interface between the repair mortar and the base concrete is less than the initial design tensile strength and the displacement at the interface between the repair mortar and the base concrete is less than 0.01 mm, and then select the solution with the smallest tensile stress and displacement at the interface between the repair mortar and the base concrete from the screened solutions as the final solution. The variables corresponding to the final solution are used as the final excavation range of the base concrete, the roughness of the base concrete, and the repair mortar.

[0022] In step 4.1, the repair mortar-base concrete model adopts the damage plasticity model embedded in the ABAQUS software.

[0023] In step 4.2, the water flow rate is 15-25 m / s.

[0024] In step 5, in the process of filling the flood channel pit with repair mortar, several stress-strain sensors are arranged at the interface between the base concrete and the repair mortar, and the distance between adjacent stress-strain sensors is 30 cm. Several rows of strength sensors are arranged inside the repair mortar, and the interval between adjacent strength sensors is 30 cm.

[0025] In step 5, the overall compressive strength of the base concrete and deep cracks after the repair mortar is poured in is not less than the initial design compressive strength, and the effect of the grouting holes on the impermeability coefficient of the base concrete is less than 10%.

[0026] The beneficial effects of the present invention are:

[0027] (1) The present invention provides a full life cycle repair method for spillway scouring pits, which adopts a repair mortar-base concrete model to obtain the optimal excavation range of the base concrete, the roughness of the base concrete, and the repair mortar, thereby ensuring the stability of the spillway during the construction period and the safety during the operation period, making it possible to treat the spillway scouring pits throughout their life cycle;

[0028] (2) The present invention provides a full life cycle repair method for spillway scouring holes. The method obtains real-time information of the spillway repair area through stress-strain sensors and strength sensors, forms quantitative detection of interface stress distribution and interface displacement, and performs continuous cycle optimization, thereby realizing the full life cycle repair planning of the spillway scouring holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a flow chart of a method for repairing spillway scouring pits throughout the life cycle of the present invention;

[0030] Figure 2 It is a schematic diagram of the layout of stress-strain sensors and strength sensors in a full life cycle repair method for spillway scour holes of the present invention.

[0031] In the figure, 1. Outline of the spillway scour pit, 2. Stress-strain sensor, 3. Strength sensor, 4. Interface between repair mortar and base concrete, 5. Deep cracks, 6. Grouting holes. DETAILED DESCRIPTION

[0032] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0033] The present invention provides a method for repairing spillway scouring holes throughout the entire life cycle, such as Figure 1 As shown, the specific implementation steps are as follows:

[0034] Step 1: perform three-dimensional scanning on the concrete surface of the spillway to be tested and conduct comprehensive ultrasonic physical detection to obtain the surface and internal three-dimensional morphological characteristics of the spillway scouring pit and obtain the material parameters of the base concrete of the spillway to be tested;

[0035] The surface morphological characteristics of spillway scouring pits include aggregate crushing morphology, mortar and aggregate distribution characteristics on the surface of spillway scouring pits;

[0036] The three-dimensional morphological characteristics of the spillway pit include the distribution characteristics of shallow cracks and deep cracks in the base concrete;

[0037] The material parameters of the spillway base concrete include base concrete compressive strength, elastic modulus, density, Poisson's ratio, and linear expansion coefficient;

[0038] The comprehensive ultrasonic physical detection is as follows: ultrasonic detection of concrete crack distribution within 10m-30m from the edge of the spillway pit (i.e., spillway pit contour line 1), ultrasonic CT imaging detection method within 0-10m from the edge of the spillway pit (i.e., spillway pit contour line 1), and combined with cross-hole resistivity CT detection method, fine detection of crack morphology, length and depth around the spillway pit;

[0039] Step 2, according to the compressive strength of the base concrete obtained in step 1, determine the excavation range of the base concrete, the roughness of the base concrete and select the repair mortar;

[0040] The excavation scope of the base concrete is determined as follows: the initial design compressive strength is obtained by consulting the original design data of the spillway, the initial design compressive strength is compared with the compressive strength of the base concrete obtained in step 1, and the base concrete whose compressive strength is less than 70% of the initial design compressive strength is excavated to obtain the excavation scope of the base concrete (the repair scope of the spillway scour pit);

[0041] The roughness of the base concrete is 0.65-1.5 mm, which is obtained by using a roughening machine;

[0042] The repair mortar shall be epoxy or polyurethane mortar and its 28-day compressive strength after solidification shall not be less than the initial design compressive strength;

[0043] Step 3, using the repair mortar selected in step 2 to prepare a repair mortar specimen, measuring the elastic modulus, density, Poisson's ratio and linear expansion coefficient of the repair mortar specimen, comparing the linear expansion coefficient of the repair mortar specimen with the linear expansion coefficient of the base concrete obtained in step 1, and the difference between the two is no more than 10%, thereby obtaining an optimized repair mortar;

[0044] Step 4, numerically simulate the repair area according to the excavation range of the spillway base concrete determined in step 2, the roughness of the base concrete and the repair mortar optimized in step 3, obtain the interface stress distribution curve and interface displacement change curve between the repair mortar and the base concrete, and determine the final excavation range of the spillway base concrete, the roughness of the base concrete, and the repair mortar;

[0045] The specific process is:

[0046] Step 4.1, using ABAQUS software to establish a repair mortar-base concrete model, and the repair mortar-base concrete model uses the damage plasticity model embedded in ABAQUS software;

[0047] The quantitative data in the repair mortar-base concrete model are the elastic modulus, density, Poisson's ratio of the base concrete obtained in step 1 and the elastic modulus, density, Poisson's ratio of the repair mortar obtained in step 3; the variables in the repair mortar-base concrete model are the base concrete excavation range, base concrete roughness and optimized repair mortar; the output results are the interface stress distribution curve and the interface displacement change curve;

[0048] The modeling range is the repair mortar optimized in step 3 and 0.5 times the distance of the longest side of the repair mortar in the direction of the base concrete. The model takes into account the different strength evolutions under tension and compression. In order to make the calculation results of the repair mortar-base concrete model have higher accuracy, the mesh division of the repair mortar-base concrete model adopts 10-node tetrahedron units, and the interface between the repair mortar and the base concrete is processed with encrypted mesh units.

[0049] Step 4.2, according to the actual environment of the spillway, apply load to the repair mortar-base concrete model established in step 4.1 to simulate the scouring load of high-speed water flow, the flow rate of the water flow is 15-25m / s, and obtain the interface stress distribution curve and the interface displacement change curve of the repair mortar and the base concrete;

[0050] Step 4.3, according to the interface stress distribution curve and interface displacement change curve obtained in step 4.2, screen out the schemes that meet the requirements that the tensile stress of the interface 4 between the repair mortar and the base concrete is less than the initial design tensile strength and the displacement of the interface 4 between the repair mortar and the base concrete is less than 0.01 mm, and then select the scheme with the smallest tensile stress and displacement of the interface 4 between the repair mortar and the base concrete as the final scheme from the screened schemes, and the variables corresponding to the final scheme are used as the final excavation range of the base concrete, the roughness of the base concrete, and the repair mortar;

[0051] Step 5, excavate according to the final excavation range of the base concrete, the base concrete roughness, and the repair mortar obtained in step 4, drill grouting holes 6 in the deep cracks 5 in the base concrete, pour the repair mortar, grind the surface of the flood channel flushing pit, and pour the repair mortar into the flood channel flushing pit, such as Figure 2 As shown, in the process of filling the repair mortar into the flood channel scouring pit, a number of stress-strain sensors 2 are arranged at the interface 4 between the repair mortar and the base concrete to monitor the changes in the interfacial stress distribution and interface displacement between the repair mortar and the base concrete, and the distance between adjacent stress-strain sensors 2 is 30 cm. A number of strength sensors 3 are arranged inside the repair mortar to monitor the strength changes of the repair mortar, and the interval between each row of strength sensors 3 is 30 cm;

[0052] The overall compressive strength of the base concrete and deep cracks after the repair mortar is poured in is not less than the initial design compressive strength, and the effect of the grouting hole 6 on the impermeability coefficient of the base concrete is less than 10%.

[0053] Step 6, obtain the stress distribution and displacement change of the interface between the repair mortar and the base concrete during the construction period and the operation period through the stress-strain sensor 2 and the strength sensor 3 deployed in step 5, and obtain the compressive strength, elastic modulus, density, Poisson's ratio, and linear expansion coefficient of the repair area. Repeat steps 2-4 to obtain the excavation range of the spillway base concrete, the roughness of the base concrete, and the repair mortar suitable for the entire life cycle.

[0054] The method of the present invention carries out a full life cycle repair plan for spillway scouring pits through cyclic optimization design. In the subsequent design and construction, a more appropriate base concrete excavation range, base concrete roughness and repair mortar type are selected to achieve step-by-step optimization and achieve the purpose of full life cycle management.

Claims

1. A full life cycle repair method for spillway scouring pits, characterized in that: Follow the steps below to implement it: Step 1: perform three-dimensional scanning on the concrete surface of the spillway to be tested and conduct comprehensive ultrasonic physical detection to obtain the surface and internal three-dimensional morphological characteristics of the spillway scouring pit and obtain the material parameters of the base concrete of the spillway to be tested; Step 2, according to the material parameters of the base concrete obtained in step 1, determine the excavation range of the base concrete, the roughness of the base concrete and select the repair mortar; Step 3, using the repair mortar selected in step 2 to prepare a repair mortar specimen, measuring the material parameters of the repair mortar specimen, and comparing the material parameters of the repair mortar specimen with the material parameters of the base concrete obtained in step 1 to obtain an optimized repair mortar; Step 4, numerically simulate the repair area according to the excavation range of the spillway base concrete determined in step 2, the roughness of the base concrete and the repair mortar optimized in step 3, obtain the interface stress distribution curve and interface displacement change curve between the repair mortar and the base concrete, and determine the final excavation range of the spillway base concrete, the roughness of the base concrete, and the repair mortar; Step 5, excavating according to the final excavation range of the base concrete, the base concrete roughness, and the repair mortar obtained in step 4, drilling grouting holes in the deep cracks in the base concrete and injecting the repair mortar, polishing the surface of the flood channel scouring pit, injecting the repair mortar into the flood channel scouring pit, and arranging the stress-strain sensor (2) and the strength sensor (3); Step 6, using the stress-strain sensor (2) and strength sensor (3) arranged in step 5 to obtain the stress distribution and displacement change of the interface between the repair mortar and the base concrete during the construction period and the operation period, the compressive strength, elastic modulus, density, Poisson's ratio, and linear expansion coefficient of the repair area are obtained, and steps 2-4 are repeated to obtain the excavation range of the spillway base concrete, the roughness of the base concrete, and the repair mortar suitable for the entire life cycle.

2. A method for repairing spillway scouring holes throughout the entire life cycle according to claim 1, characterized in that: In step 1, the material parameters of the spillway base concrete include the base concrete compressive strength, elastic modulus, density, Poisson's ratio, and linear expansion coefficient.

3. A full life cycle repair method for spillway scouring pits according to claim 1, characterized in that: In step 2, the excavation range of the base concrete is determined by: obtaining the initial design compressive strength by consulting the original design data of the spillway, comparing the initial design compressive strength with the base concrete compressive strength obtained in step 1, and excavating the base concrete whose compressive strength is less than 70% of the initial design compressive strength to obtain the excavation range of the base concrete; The roughness of the base concrete is 0.65 to 1.5 mm; The repair mortar shall use epoxy or polyurethane mortar and its 28-day compressive strength after solidification shall not be less than the initial design compressive strength.

4. A full life cycle repair method for spillway scouring pits according to claim 2, characterized in that: The specific process of step 3 is: use the repair mortar screened in step 2 to prepare a repair mortar specimen, measure the elastic modulus, density, Poisson's ratio and linear expansion coefficient of the repair mortar specimen, and compare the linear expansion coefficient of the repair mortar specimen with the linear expansion coefficient of the base concrete obtained in step 1. The difference between the two is no more than 10%, and the optimized repair mortar is obtained.

5. A method for repairing spillway scouring holes throughout the entire life cycle according to claim 1, characterized in that: The specific process of step 4 is: Step 4.1, using ABAQUS software to establish a repair mortar-base concrete model, the quantitative in the repair mortar-base concrete model is the elastic modulus, density, Poisson's ratio of the base concrete obtained in step 1 and the elastic modulus, density, Poisson's ratio of the repair mortar obtained in step 3; the variables in the repair mortar-base concrete model are the excavation range of the base concrete, the roughness of the base concrete and the optimized repair mortar; the output results are the interface stress distribution curve and the interface displacement change curve; Step 4.2, according to the actual environment of the spillway, a load is applied to the repair mortar-base concrete model established in step 4.1 to simulate the scouring load of high-speed water flow, and obtain the stress distribution curve of the interface between the repair mortar and the base concrete and the displacement change curve of the interface between the repair mortar and the base concrete; Step 4.3, based on the interface stress distribution curve and interface displacement change curve obtained in step 4.2, screen out the solutions that meet the requirements that the tensile stress at the interface between the repair mortar and the base concrete is less than the initial design tensile strength and the displacement at the interface between the repair mortar and the base concrete is less than 0.01 mm, and then select the solution with the smallest tensile stress and displacement at the interface between the repair mortar and the base concrete from the screened solutions as the final solution. The variables corresponding to the final solution are used as the final excavation range of the base concrete, the roughness of the base concrete, and the repair mortar.

6. A full life cycle repair method for spillway scouring pits according to claim 5, characterized in that: In step 4.1, the repair mortar-base concrete model adopts the damage plasticity model embedded in the ABAQUS software.

7. A full life cycle repair method for spillway scouring pits according to claim 5, characterized in that: In step 4.2, the water flow rate is 15-25 m / s.

8. The full life cycle repair method of a spillway scouring pit according to claim 1 is characterized in that: In step 5, in the process of filling the flood channel pit with repair mortar, a plurality of stress-strain sensors (2) are arranged at the interface between the repair mortar and the base concrete, and the distance between adjacent stress-strain sensors (2) is 30 cm. A plurality of rows of strength sensors (3) are arranged inside the repair mortar, and the interval between adjacent strength sensors (3) is 30 cm.

9. A method for repairing spillway scouring holes throughout the life cycle according to claim 1, characterized in that: In step 5, the overall compressive strength of the base concrete and deep cracks after the repair mortar is poured in is not less than the initial design compressive strength, and the effect of the grouting holes on the impermeability coefficient of the base concrete is less than 10%.

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