CN106370329B - A kind of roller compacted concrete dam structure performance monitoring system and monitoring method - Google Patents

Abstract

The invention discloses a kind of RCC dam structure behaviour monitoring system and monitoring methods, including structure behaviour monitoring device and curved tune device, structure behaviour monitoring device is connected by temperature sensing optical fiber with curved tune device, based on temperature information acquired in temperature sensing optical fiber, consider the otherness of RCC dam ontology and level thermal parameters, based on grinding coagulation soil linear expansion coefficient, the thermal parameters equivalent analysis such as specific heat carries out calculating analysis using finite element temperature strain incremental computations form, level and the ontology line strain and shear strain due to caused by the otherness of thermal parameters of RCC dam are considered simultaneously, and then RCC dam structure behaviour is analysed and evaluated, distributed monitoring based on temperature sensing optical fiber, substantially increase the ability of monitoring, it is structural admirably to meet practical RCC dam The demand of state diagnosis, probes into current RCC dam structure behaviour health monitoring and provides important guarantee.

Description

A kind of roller compacted concrete dam structure performance monitoring system and monitoring method

technical field

The invention relates to a monitoring system and method for the structural properties of a roller compacted concrete dam, belonging to the field of safety and health monitoring of water engineering structures.

Background technique

Since the first RCC dam was successfully built in my country in 1986, it is estimated that there are about 50 RCC dams built or under construction, which is one of the promising dam types in my country. The RCC dams with a height of more than 100m that have been built recently, are under construction and will be under construction include Longtan (216m), Jiangya (131m), Baise (126m), Dachaoshan (121m) and Mianhuatan (111m). The amount of roller compacted concrete is more than 60% of that of the entire dam.

my country's roller-compacted concrete dam building technology was developed on the basis of absorbing foreign advanced technologies in the 1980s, but it also created its own unique experience, but there are still many aspects that need in-depth research on roller-compacted concrete dams. For example, more and more attention has been paid to the change law of the temperature field of the roller compacted concrete dam and the influence of the variable temperature field on the structural behavior of the dam body. The research on the effect of dam action and its influence is still an important topic in the industry.

In 1968, Wilson, a professor of civil engineering at the University of California, first developed a two-dimensional temperature field finite element simulation program DOT-DICE for the U.S. Army Corps of Engineers for staged construction of mass concrete structures, which was successfully applied to the Dworshak Dam. The program was further modified in 1985 by engineers Tatro and Schrader of the U.S. Army Corps of Engineers to use it for the temperature field analysis of WillowCreak, the first roller compacted concrete dam (RCCD) in the United States, In 1992, Tobishima Corporation of Japan published an inverse analysis method for thermal and boundary property parameters based on the measured data based on finite element. For the current structural behavior of roller compacted concrete dams, it is urgent to develop a method that can truly detect roller compaction. Although the technology of concrete dam temperature field and various numerical simulation technologies are advanced, they are simulation simulations after all, and there are huge problems in their authenticity and reference.

SUMMARY OF THE INVENTION

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a system and a monitoring method for the structural behavior of a roller compacted concrete dam, breaking through the traditional monitoring idea, and firstly proposes a structure based on temperature sensing optical fiber technology. The state monitoring device and bending adjustment device can monitor the service behavior of the roller compacted concrete dam structure to the greatest extent in the real situation. The distributed monitoring based on the temperature sensing fiber greatly improves the monitoring ability and satisfies the The demand for the diagnosis of the structural behavior of the actual RCC dam provides an important guarantee for the current research on the health monitoring of the structural behavior of the RCC dam.

In order to solve the above technical problems, a system for monitoring the structural behavior of a roller compacted concrete dam of the present invention includes a structural behavior monitoring device and a bending adjustment device, and the structural behavior monitoring device is connected with the bending adjustment device through a temperature sensing optical fiber;

The structural performance monitoring device includes: a loading card table, a chamfering table, a first arc table, a second arc table, a first bottom edge table and a second bottom edge table. The first arc stage is connected with the second arc stage, the tip of the first arc stage is connected to the first carrier cavity, the tip of the second arc stage is connected to the second carrier cavity, and the temperature sensing fiber is connected by a load-carrying card It is led out from one side of the table, and passes through the first arc table, the first carrier end cavity, the first bottom edge table, the bending device, the second bottom edge table, the second carrier end cavity and the second arc table in sequence, and the load is carried smoothly. The other side of the card table leads out;

The bending and adjusting device includes: a main rotating core, a fan-shaped blade, a main bending arc and a first round hole screw and a second round hole screw for fixing. The main rotating core is set at the cone end of the fan-shaped blade, and the main bending arc is set at the At the arc edge of the blade, the bending device bends the temperature sensing fiber to the main bending arc through the fan blade;

The first carrier end cavity is opened with a first outer lead hole, and the second carrier end cavity is opened with a second outer lead hole, and the first carrier end cavity and the second outer lead hole are respectively opened through the first outer lead hole and the second outer lead hole. Inject the gel into the carrier end cavity,

A first outer screwing hole is opened on the first bottom ledge, a second outer screwing hole is opened on the second bottom ledge, and the first outer screwing hole and the second outer screwing hole are respectively arranged on the temperature sensor Both ends of the optical fiber, and outdoor thermometers are respectively placed in the first outer screw hole and the second outer screw hole;

The structural performance monitoring device is provided with a first fiber rotation axis and a first fiber rotation column on one side corresponding to the first arc table, and a second fiber rotation axis and a second fiber rotation column on the other side corresponding to the second arc table The first and second fiber rotation shafts pass through the first and second fiber rotation columns respectively, and the first and second fiber rotation columns are adjusted by rotating the first and second fiber rotation shafts. The distance between the spinning columns, after the temperature sensing fiber is laid out, lock the first spinning shaft and the second spinning shaft.

The chamfered table is an inclined structure with an included angle of 60° from the horizontal, and the first arc table and the second arc table are arc structures with radians of both π/3.

In the bending and adjusting device, the fan-shaped blade can rotate 360° around the main rotating core. At the top of the fan-shaped blade is the main bending arc with an arc of π/3. After the adjustment is completed, the bending and adjusting device is fixed and set by the first round hole screw and the second round hole screw.

A monitoring method for a roller compacted concrete dam structure performance monitoring system, comprising the following steps:

The first step is to connect the structural property monitoring device and the bending device through the temperature sensing fiber. Straighten, one end of which is led to the first bottom prism, the first carrier end cavity and the first arc platform in turn, and the other end is led to the second bottom prism, the second carrier end cavity and the second arc platform in turn, and the The first outer guide hole and the second outer guide hole inject the gel into the first carrier end cavity and the second carrier end cavity respectively, and then pass through the first fiber rotation axis, the second fiber rotation axis and the first fiber rotation column, The second fiber swivel column fixes the temperature sensing fiber in the holding card table, and installs an outdoor thermometer on the first outer screw hole and the second outer screw hole. After the layout is completed, start to obtain the temperature sensing fiber on the temperature data;

In the second step, the temperature value at each part of the dam body monitored by the temperature sensing fiber forms a temperature field. For a three-dimensional RCC dam, according to the initial time of the dam T(x,y,z,t)| _t The temperature field formed by the node temperature determined by = ₀ is the initial temperature field of the roller compacted concrete dam, denoted as The temperature field formed by the unit node temperature φ _i at any time is x, y, and z are the coordinates of the nodes in the x, y, and z directions of the dam, and t is the time;

In the third step, when only the linear strain is considered and the shear strain is not considered, the strain ε _T generated by thermal deformation is:

In the formula, α _l is the temperature linear expansion coefficient in the y direction; α _v is the temperature linear expansion coefficient in the z direction;

In the fourth step, the roller compacted concrete dam is subjected to other external loads and constraints. During the temperature change process, the roller compacted concrete dam has an initial strain ε. In this case, the roller compacted concrete dam finite element analysis method is used to The relationship between stress σ and strain ε for temperature effect is:

in, is the equivalent elastic matrix of the roller compacted concrete dam, ε _T is the strain generated by thermal deformation; the physical equation of its incremental form is:

In the formula: {Δε _Tn } is the strain increment due to temperature change during the ΔT _n period, {Δε _n } is the node strain increment, and {Δσ _n } is the node stress increment;

In the fifth step, through the operations of the above steps, the purpose of monitoring the stress and strain conditions of the nodes is realized, and finally the structural behavior of each position of the roller compacted concrete dam is judged.

Beneficial effects: The present invention breaks through the traditional RCC dam structural behavior monitoring and analysis method, firstly proposes a structural behavior monitoring device and a bending device based on temperature sensing optical fiber technology, and constructs a multi-module high-precision sensing device. The optical fiber monitoring device, based on the equivalent analysis of thermal parameters such as RCC linear expansion coefficient and specific heat, calculates the effect of the RCC dam under the action of temperature changes, and maximally realizes the monitoring of the RCC dam structure under real conditions. service behavior.

Description of drawings

Fig. 1 is the monitoring flow chart of the monitoring method of the roller compacted concrete dam structure performance monitoring system of the present invention;

2 is a schematic structural diagram of a structural state monitoring device in the present invention;

Fig. 3 is the side view of Fig. 2;

Fig. 4 is the structural representation of the bending adjustment device in the present invention;

Fig. 5 is the finite element mesh diagram of RCCD6# dam section in the present invention;

Fig. 6 is the structural representation of the unit body M composed of the roller compacted concrete dam body and the thin layer of the present invention;

Figure 7 is the location diagram of A6-C-04 measuring point and A6-C-05 measuring point;

Figure 8 is a comparison diagram of the process line between the finite element calculation and the measured value of the normal stress of the A6-C-04 measuring point perpendicular to the dam foundation surface;

Figure 9 is a comparison diagram of the process line between the finite element calculation and the measured value of the normal stress of the A6-C-05 measuring point perpendicular to the dam foundation surface;

FIG. 10 is a schematic diagram of the ABCD shear strain of the microelement.

Among them: 00-loading card table; 01-bevel cutting table; 02-first arc table; 03-first outer lead hole; 04-first end-carrying cavity; 05-temperature sensing fiber; 06-first 07-The first fiber axis; 08-The second fiber axis; 09-The second fiber column; 10-The second outer lead hole; 11-The second carrier cavity; 12-The first bottom edge table; 13-first external screw connection hole; 14-second bottom prism; 15-second external screw connection hole; 16-main rotating core; 17-sector blade; 18-first round hole screw; 19-main Bending arc; 20-second round hole screw; 21-body; 22-layer; 26-second arc table.

Detailed ways

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are all simplified schematic diagrams, and only illustrate the basic structure of the present invention in a schematic manner, so they only show the structures related to the present invention.

A structural state monitoring system for a roller compacted concrete dam, comprising a structural state monitoring device and a bending adjustment device, wherein the structural state monitoring device is connected with the bending adjustment device through a temperature sensing optical fiber;

The structural performance monitoring device includes: a loading card table, a chamfering table, a first arc table, a second arc table, a first bottom edge table and a second bottom edge table. The first arc stage is connected with the second arc stage, the tip of the first arc stage is connected to the first carrier cavity, the tip of the second arc stage is connected to the second carrier cavity, and the temperature sensing fiber is connected by a load-carrying card It is led out from one side of the table, and passes through the first arc table, the first carrier end cavity, the first bottom edge table, the bending device, the second bottom edge table, the second carrier end cavity and the second arc table in sequence, and the load is carried smoothly. The other side of the card table leads out;

The bending and adjusting device includes: a main rotating core, a fan-shaped blade, a main bending arc and a first round hole screw and a second round hole screw for fixing. The main rotating core is set at the cone end of the fan-shaped blade, and the main bending arc is set at the At the arc edge of the blade, the bending device bends the temperature sensing fiber to the main bending arc through the fan blade;

The first carrier end cavity is opened with a first outer lead hole, and the second carrier end cavity is opened with a second outer lead hole, and the first carrier end cavity and the second outer lead hole are respectively opened through the first outer lead hole and the second outer lead hole. Inject the gel into the carrier end cavity,

A first outer screwing hole is opened on the first bottom ledge, a second outer screwing hole is opened on the second bottom ledge, and the first outer screwing hole and the second outer screwing hole are respectively arranged on the temperature sensor Both ends of the optical fiber, and outdoor thermometers are respectively placed in the first outer screw hole and the second outer screw hole;

The structural performance monitoring device is provided with a first fiber rotation axis and a first fiber rotation column on one side corresponding to the first arc table, and a second fiber rotation axis and a second fiber rotation column on the other side corresponding to the second arc table The first and second fiber rotation shafts pass through the first and second fiber rotation columns respectively, and the first and second fiber rotation columns are adjusted by rotating the first and second fiber rotation shafts. The distance between the spinning columns, after the temperature sensing fiber is laid out, lock the first spinning shaft and the second spinning shaft.

The chamfered table is an inclined structure with an included angle of 60° from the horizontal, and the first arc table and the second arc table are arc structures with radians of both π/3. The setting of this combination structure is mainly to increase the cooperative deformation characteristics with the structure to be measured, so as to ensure that the temperature sensing optical fiber can be effectively laid and monitored.

In the bending and adjusting device, the fan-shaped blade can rotate 360° around the main rotating core. At the top of the fan-shaped blade is the main bending arc with an arc of π/3. After the adjustment is completed, the bending and adjusting device is fixed and set by the first round hole screw and the second round hole screw.

A monitoring method for a roller compacted concrete dam structure performance monitoring system, comprising the following steps:

The first step is to connect the structural property monitoring device and the bending device through the temperature sensing fiber. Straighten, one end of which is led to the first bottom prism, the first carrier end cavity and the first arc platform in turn, and the other end is led to the second bottom prism, the second carrier end cavity and the second arc platform in turn, and the The first outer guide hole and the second outer guide hole inject the gel into the first carrier end cavity and the second carrier end cavity respectively, and then pass through the first fiber rotation axis, the second fiber rotation axis and the first fiber rotation column, The second fiber swivel column fixes the temperature sensing fiber in the holding card table, and installs an outdoor thermometer on the first outer screw hole and the second outer screw hole. After the layout is completed, start to obtain the temperature sensing fiber on the temperature data;

In the second step, the temperature value at each part of the dam body monitored by the temperature sensing fiber forms a temperature field. For a three-dimensional RCC dam, according to the initial time of the dam T(x,y,z,t)| _t The temperature field formed by the node temperature determined by ₌₀ is the initial temperature field of the roller compacted concrete dam, denoted as The temperature field formed by the unit node temperature φ _i at any time is

In the third step, when only the linear strain is considered and the shear strain is not considered, the strain ε _T generated by thermal deformation is:

In the formula, α _l is the temperature linear expansion coefficient in the y direction; α _v is the temperature linear expansion coefficient in the z direction;

In the fourth step, the roller compacted concrete dam is subjected to other external loads and constraints. During the temperature change process, the roller compacted concrete dam has an initial strain ε. In this case, the roller compacted concrete dam finite element analysis method is used to The relationship between stress σ and strain ε for temperature effect is:

in, is the equivalent elastic matrix of the roller compacted concrete dam, ε _T is the strain generated by thermal deformation; the physical equation of its incremental form is:

In the formula: {Δε _Tn } is the strain increment due to temperature change during the ΔT _n period, {Δε _n } is the node strain increment, and {Δσ _n } is the node stress increment;

In the fifth step, through the operations of the above steps, the purpose of monitoring the stress and strain conditions of the nodes is realized, and finally the structural behavior of each position of the roller compacted concrete dam is judged.

Optical fiber sensing technology is a new type of sensing technology developed in recent decades. It uses light waves as sensing signals. When the sensing fiber is subjected to external stress, temperature and other environmental factors, the light waves transmitted in the fiber It is very easy to be modulated by these external fields or quantities, and then changes in the parameters of light waves, such as changes in light intensity, phase, frequency, polarization state, etc., can be obtained by monitoring the changes of these information.

Based on the above background, the patent of the present invention breaks through the traditional method of monitoring and analyzing the structural behavior of roller compacted concrete dams. The sensing optical fiber monitoring device can monitor the service behavior of the RCC dam structure to the greatest extent in the real situation.

Example 1

A roller-compacted concrete dam is located on the middle reaches of the Jinsha River in Lijiang, Yunnan Province. The maximum dam height is 160m, and the dam crest is 640m long; the maximum length in the downstream direction is 156m. The structural behavior of the dam section under the action of variable temperature load, water pressure load and other factors from the construction period to the operation period is studied. During the research process, the compressive stress measurement points A6-C-04 and A6-C-05 on the dam foundation surface are used as typical measurement points For analysis and research, the calculation domain of the 6# dam section of the roller compacted concrete dam is divided into 21290 units and 26690 nodes. The finite element is shown in Figure 5. The RCC dam is simulated and calculated from the construction period to the operation period. During the calculation, the strain increment and the stress increment of each time period are obtained according to the calculation method of the temperature-variable load action effect of the present invention.

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figures 1 to 10, a roller compacted concrete dam structural performance monitoring system of the present invention includes a structural performance monitoring device and a bending adjustment device. Connected to the bending and adjusting device, the structural state monitoring device mainly includes a load-carrying card table 00 with a length of 50cm, a width of 80cm, and a height of 30cm, and a beveled table 01 with a length of 20cm, a width of 80cm, and a height of 30cm. The arc is π/3, The first arc table 02 with a height of 40cm, the second arc table 26 with a radian of π/3 and a height of 40cm, and a holding card table 00 with a length of 50cm, a width of 80cm, and a height of 30cm pass the The bevel table 01 is connected to the first arc table 02 with an arc of π/3 and a height of 40cm. The bevel table is an inclined structure with an included angle of 60° from the horizontal, and the first arc of π/3 and a height of 40cm. The arc platform 02 and the second arc platform 26 with a radian of π/3 and a height of 40cm are arc-shaped structures with a radian of π/3. The setting of this combination structure is mainly to increase the cooperative deformation characteristics with the structure to be measured. , to ensure the effective deployment and monitoring of the temperature sensing fiber. The tip of the first arc table 02 with a radian of π/3 and a height of 40cm is connected to the first carrier end cavity 04 with a diameter of 0.5cm and a length of 2cm. The GJJV model is tightly sleeved. After the temperature sensing fiber 05 passes through the first end-carrying cavity 04 with a diameter of 0.5 cm and a length of 2 cm, it is connected to the first bottom edge platform 12 with a length, width and height of 5 cm. The GJJV type tight-sleeve temperature sensing fiber 05 protruding from the bottom edge table 12 is connected to the bending and adjusting device. After the GJJV type tight-fitting temperature sensing fiber 05 passes through the bending and adjusting device, it is connected to the second bottom prism with a length, width and height of 5cm. 14 is connected, and then connected to the second arc platform 26 with a radian of π/3 and a height of 40cm.

In the present invention, the left and right sides of the structural performance monitoring device include a first fiber-rotating shaft 07 with a diameter of 0.5 cm and a length of 5 cm, a second fiber-rotating shaft 08 with a diameter of 0.5 cm and a length of 5 cm, and a first rotating fiber shaft with a diameter of 5 cm and a thickness of 2 cm. The fiber column 06, the second rotating fiber column 09 with a diameter of 5 cm and a thickness of 2 cm, a first rotating fiber shaft 07 with a diameter of 0.5 cm and a length of 5 cm, and a second rotating fiber shaft 08 with a diameter of 0.5 cm and a length of 5 cm pass through the diameter of 5 cm and the thickness. The first fiber-rotating column 06 of 2cm and the second fiber-rotating column 09 with a diameter of 5cm and a thickness of 2cm are rotated by rotating the first fiber-rotating axis 07 with a diameter of 0.5cm and a length of 5cm and a second fiber-rotating axis with a diameter of 0.5cm and a length of 5cm. 08 Adjust the distance between the first rotating fiber column 06 with a diameter of 5 cm and a thickness of 2 cm and the second rotating fiber column 09 with a diameter of 5 cm and a thickness of 2 cm. cm, a first fiber optic axis 07 with a length of 5 cm, and a second fiber optic axis 08 with a diameter of 0.5 cm and a length of 5 cm.

In the present invention, the first carrier end cavity 04 with a diameter of 0.5cm and a length of 2cm is provided with a first outer lead hole 03 with a diameter of 0.1cm and a height of 1cm, and the second carrier end cavity 11 with a diameter of 0.5cm and a length of 2cm is opened with a The second outer guide hole 10 with a diameter of 0.1cm and a height of 1cm passes through the first outer guide hole 03 with a diameter of 0.1cm and a height of 1cm and the second outer guide hole 10 with a diameter of 0.1cm and a height of 1cm to a 0.5cm diameter and a length of 2cm. The composite gel is injected into the first carrier end cavity 04 and the second carrier end cavity, and a first outer screw hole 13 with a diameter of 0.2 cm is opened on the first bottom ledge 12 with a length, width and height of 5 cm. A second outer screw hole 15 with a diameter of 0.2 cm is opened on the second bottom prism 14 with a width and height of 5 cm, and the first outer screw hole 13 and the second outer screw hole 15 with a diameter of 0.2 cm are respectively arranged in the GJJV The model tightly covers both ends of the temperature sensing fiber 05, and the first outer screw hole 13 and the second outer screw 15 with a diameter of 0.2 cm are mainly used for placing outdoor thermometers.

In the present invention, the bending adjustment device mainly includes a main rotor core 16 with a diameter of 1cm and a height of 30cm, a fan-shaped blade 17 with a height of 30cm and an arc of π/3, a first round hole screw 18 of a diameter of 1cm and a height of 5cm, and an arc of π/3. The main bending arc 19, the second round hole screw 20 with a diameter of 1 cm and a height of 5 cm, bends the GJJV model tight-fitting temperature sensing fiber 05 to the main bending arc through the fan-shaped blade 17 of radian π/3, and passes through the diameter of 1 cm. , The first round hole screw 18 with a height of 5cm and the second round hole screw 20 with a diameter of 1cm and a height of 5cm can effectively fix and set the bending device, and the fan-shaped blade 17 with an arc of π/3 can be wound around a diameter of 1cm and a height of 30cm. The main rotor core 16 rotates 360°, at the top of the fan blade 17 with radian π/3 is the main bending arc 19 with radian π/3, the GJJV model tight-sleeve temperature sensing fiber 05 passes through the main bending of radian π/3 The arc 19 performs transition adjustment at the bend. After the adjustment is completed, the first round hole screw 18 with a diameter of 1 cm and a height of 5 cm and a second round hole screw 20 with a diameter of 1 cm and a height of 5 cm are used to effectively fix and set the bending device.

A monitoring method for a roller compacted concrete dam structure performance monitoring system, comprising the following steps:

(1) The layout and adjustment of the device;

The structural property monitoring device and the bending device are connected through the GJJV type tight-fitting temperature sensing fiber 05. First, the bending and adjusting device is used to effectively bend the part to be bent, and then the two parts of the GJJV type tight-fitting temperature sensing fiber 05 are connected. The ends are straightened, and one end is led to the first bottom prism, the first carrier end cavity and the first arc platform in turn, and the other end is led to the second bottom prism, the second carrier end cavity and the second arc platform in sequence, The gel is injected into the first carrier end cavity 04 and the second carrier end cavity 11 through the first outer guide hole 03 and the second outer guide hole 10, and then passes through the first fiber optic shaft 07, the second fiber optic shaft 08 and the The first fiber-rotating column 06 and the second fiber-rotating column 09 fix the temperature sensing fiber 05 in the loading card table 00, and install an outdoor thermometer on the first outer screw hole 13 and the second outer screw hole 15, After the layout is completed, start to obtain the temperature data on the temperature sensing fiber 05;

(2) Build a temperature field;

The temperature value at each part of the dam body monitored by the temperature sensing fiber 05 in the previous step forms the temperature field. For a three-dimensional RCC dam, according to the initial time of the dam T(x,y,z,t)| _t The temperature field formed by the node temperature determined by ₌₀ is the initial temperature field of the roller compacted concrete dam, denoted as And the temperature field formed by the unit node temperature φ _i at any time is

(3) Calculate the thermal deformation strain when only the linear strain is considered, and the shear strain is not considered;

Based on the content of step (2), we can get:

Among them, n _e is the number of elements, N _i is the shape function, is the temperature field formed by n _e units at any time;

The dam body is determined by the initial temperature field change to temperature field The strain ε _T due to thermal deformation is:

where α is the temperature linear expansion coefficient,

In this project, the roller compacted concrete dam is subject to other external loads and constraints. During the temperature change process, the roller compacted concrete dam has an initial strain ε. In this case, the relationship between the displacement δ and the strain ε is: (ε-ε _T )=Bδ; where B=[B ₁ B ₂ B ₃ …B _m ] ^T :

Element Stiffness Matrix

where: is the equivalent elastic matrix of the roller compacted concrete dam, B is the coefficient matrix, and B ^T is the transpose matrix of the coefficient matrix;

is the area to be integrated;

In the third step, when only the linear strain is considered and the shear strain is not considered, and the initial temperature field is change to temperature field strain ε _T due to thermal deformation;

In the formula, α is the temperature linear expansion coefficient;

Select the unit body M of the roller compacted concrete dam composed of the main body 21 and the layer 22; the unit body M has a horizontal equivalent temperature linear expansion coefficient of α _l and a vertical equivalent temperature linear expansion coefficient of α _v . Without other constraints, Only under the action of temperature difference ΔT; the line strain along the direction of layer 22 is:

In the formula, is the linear strain of the element body M in the x direction, is the linear strain of the unit body M in the y direction;

The line strain perpendicular to the direction of layer 22 is:

In the formula, is the linear strain of the unit body M in the z direction; select the micro-unit ABCD of ds×ds, and the micro-unit ABCD is in the yz plane perpendicular to the direction 22 of the RCC dam layer; then each point of the micro-unit ABCD The coordinates are A:(0,0), B:(ds,0), C:(ds,ds), D:(0,ds); under the action of variable temperature ΔT, the micro-body ABCD deforms into AB'C 'D', AB shear strain is α, AD shear strain is β, y-direction temperature linear expansion coefficient is α _l , z-direction temperature linear expansion coefficient is α _v , under the action of temperature ΔT, the micro-element body is displaced to AB'C 'D', ignoring the influence of the second-order infinitesimal lengths of ΔT·α _l ·ds and ΔT·α _v ·ds, the coordinates of the point B'C'D' are:

B':([ds+ΔT· _αl ·ds],ΔT· _αv ·ds),C':([ds+ΔT· _αl ·ds],[ds+ΔT· _αv ·ds]),

Then there are: D':(ΔT· _αl ·ds,[ds+ΔT· _αv ·ds]);

In the formula, is the shear strain of the micro-body ABCD in the y and z directions;

In this actual project, both ΔT·α _v and ΔT·α _l are far less than 1, so it is advisable to:

Also there are:

In the formula, are the shear strains of the micro-body ABCD in the z and x directions, is the shear strain of the micro-element ABCD in the x and y directions; therefore, without other constraints, only under the action of the temperature difference ΔT, the temperature strain increment equation of the element M is:

In the formula: ΔT is the temperature difference;

(4) Monitor the stress and strain conditions of the nodes and judge the structural behavior of each position of the roller compacted concrete dam;

The roller compacted concrete dam is subjected to other external loads and constraints, and there is an initial strain ε in the roller compacted concrete dam during the temperature change process. The relationship between stress σ and strain ε is:

in, is the equivalent elastic matrix of the roller compacted concrete dam, ε _T is the strain generated by thermal deformation; the physical equation of its incremental form is:

where {Δε _Tn } is the strain increment due to temperature change during the ΔT _n period, {Δε _n } is the node strain increment, {Δσ _n } is the node stress increment,

Through the operation of the above steps, the compressive stress process line perpendicular to the dam foundation surface of typical measuring points is constructed and compared with the measured value process line, as shown in Figures 8 to 9. It can be seen from Figures 8 to 9 that the construction period increases with the The elevation of the dam body increases, and the compressive stress on the dam foundation surface increases due to the action of its own weight. After the dam is impounded, under the action of the upstream reservoir water level, the compressive stress on the upstream side of the dam foundation decreases, and the compressive stress near the downstream increases. The overall finite element simulation The compressive stress hydrographs of the dam foundation surface obtained at typical measuring points are consistent with the measured change laws of the measured points, indicating that the numerical simulation calculation method of the roller compacted concrete dam proposed in this paper can better reflect the temperature change effect of the roller compacted concrete dam and the change laws of the structural behavior. , and finally completed the work of judging the structural properties of each position of the RCC dam.

The above is only the preferred embodiment of the present invention, it should be pointed out that: for those skilled in the art, without departing from the principle of the present invention, several improvements and modifications can also be made, and these improvements and modifications are also It should be regarded as the protection scope of the present invention.

Claims (4)

1. a roller compacted concrete dam structural state monitoring system, is characterized in that: comprise a structural state monitoring device and a bending adjustment device, and the structural behavior monitoring device is connected with the bending adjustment device by a temperature sensing optical fiber; The structural performance monitoring device includes: a loading card table, a chamfering table, a first arc table, a second arc table, a first bottom edge table and a second bottom edge table. The first arc stage is connected with the second arc stage, the tip of the first arc stage is connected to the first carrier cavity, the tip of the second arc stage is connected to the second carrier cavity, and the temperature sensing fiber is connected by a load-carrying card It is led out from one side of the table, and passes through the first arc table, the first carrier end cavity, the first bottom edge table, the bending device, the second bottom edge table, the second carrier end cavity and the second arc table in sequence, and the load is carried smoothly. The other side of the card table leads out; The bending and adjusting device includes: a main rotating core, a fan-shaped blade, a main bending arc and a first round hole screw and a second round hole screw for fixing. The main rotating core is set at the cone end of the fan-shaped blade, and the main bending arc is set at the At the arc edge of the blade, the bending device bends the temperature sensing fiber to the main bending arc through the fan blade; The first carrier end cavity is opened with a first outer lead hole, and the second carrier end cavity is opened with a second outer lead hole, and the first carrier end cavity and the second outer lead hole are respectively opened through the first outer lead hole and the second outer lead hole. Inject the gel into the carrier end cavity, A first outer screwing hole is opened on the first bottom ledge, a second outer screwing hole is opened on the second bottom ledge, and the first outer screwing hole and the second outer screwing hole are respectively arranged on the temperature sensor Both ends of the optical fiber, and outdoor thermometers are respectively placed in the first outer screw hole and the second outer screw hole; The structural performance monitoring device is provided with a first fiber rotation axis and a first fiber rotation column on one side corresponding to the first arc table, and a second fiber rotation axis and a second fiber rotation column on the other side corresponding to the second arc table The first and second fiber rotation shafts pass through the first and second fiber rotation columns respectively, and the first and second fiber rotation columns are adjusted by rotating the first and second fiber rotation shafts. The distance between the spinning columns, after the temperature sensing fiber is laid out, lock the first spinning shaft and the second spinning shaft. 2. The roller compacted concrete dam structure performance monitoring system according to claim 1 is characterized in that: the oblique cutting platform is an inclined structure with an included angle of 60° with the horizontal, and the first arc platform and the second arc platform are The radians are all arc structures with π/3. 3. A system for monitoring the structural performance of a roller compacted concrete dam according to claim 1, wherein the fan-shaped blade in the bending adjustment device can be rotated 360° around the main rotating core, and the top of the fan-shaped blade is radian. It is the main bending arc of π/3, and the temperature sensing optical fiber performs transition adjustment at the bending position through the main bending arc. After the adjustment is completed, the bending adjustment device is fixed and set by the first round hole screw and the second round hole screw. 4. the monitoring method of a kind of roller compacted concrete dam structure performance monitoring system as claimed in claim 1, is characterized in that, comprises the following steps: The first step is to connect the structural property monitoring device and the bending device through the temperature sensing fiber. Straighten, one end of which is led to the first bottom prism, the first carrier end cavity and the first arc platform in turn, and the other end is led to the second bottom prism, the second carrier end cavity and the second arc platform in turn, and the The first outer guide hole and the second outer guide hole inject the gel into the first carrier end cavity and the second carrier end cavity respectively, and then pass through the first fiber rotation axis, the second fiber rotation axis and the first fiber rotation column, The second fiber swivel column fixes the temperature sensing fiber in the holding card table, and installs an outdoor thermometer on the first outer screw hole and the second outer screw hole. After the layout is completed, start to obtain the temperature sensing fiber on the temperature data; In the second step, the temperature value at each part of the dam body monitored by the temperature sensing fiber forms a temperature field. For a three-dimensional RCC dam, according to the initial time of the dam T(x,y,z,t)| _t The temperature field formed by the node temperature determined by ₌₀ is the initial temperature field of the roller compacted concrete dam, denoted as The temperature field formed by the unit node temperature φ _i at any time is x, y, and z are the coordinates of the nodes in the x, y, and z directions of the dam, and t is the time; In the third step, when only the linear strain is considered and the shear strain is not considered, the strain ε _T generated by thermal deformation is: In the formula, α _l is the temperature linear expansion coefficient in the y direction; α _v is the temperature linear expansion coefficient in the z direction; In the fourth step, the roller compacted concrete dam is subjected to other external loads and constraints. During the temperature change process, the roller compacted concrete dam has an initial strain ε. In this case, the roller compacted concrete dam finite element analysis method is used to The relationship between stress σ and strain ε for temperature effect is: in, is the equivalent elastic matrix of the roller compacted concrete dam, ε _T is the strain generated by thermal deformation; the physical equation of its incremental form is: In the formula: {Δε _Tn } is the strain increment due to temperature change during the ΔT _n period, {Δε _n } is the node strain increment, and {Δσ _n } is the node stress increment; In the fifth step, through the operations of the above steps, the purpose of monitoring the stress and strain conditions of the nodes is realized, and finally the structural behavior of each position of the roller compacted concrete dam is judged.