Stress monitoring method for bridge deck and newly-built bearing platform in bridge structure
阅读说明：本技术 一种桥梁结构中桥面板和新建承台的应力监测方法 (Stress monitoring method for bridge deck and newly-built bearing platform in bridge structure ) 是由 刘洪涛 孙广 张鹏飞 郝永攀 曹崇 盖忠奎 苗新涛 杜盼强 王龙 田力 阮晓雨 于 2020-07-30 设计创作，主要内容包括：本发明公开一种桥梁结构中桥面板和新建承台的应力监测方法,包括以下步骤：(1)监测点布置,在桥梁两侧的桥面板板底和承台两侧均布设监测点；(2)监测方法及要求,对于承台采用内埋式应变计监测；对桥面板板底采用表面式应变计监测；1)内埋式应变计,在承台的监测点内埋设钢筋计,对内置有温度传感器的钢筋计的数据进行统计和监测；2)表面式应变计,将表面应变计安装于桥面板板底监测点的外表面,对内置有温度传感器的表面应变计的数据进行统计和监测；(3)数据处理与分析,进而判断桥梁结构新建承台的应力变化情况。根据该监测方法对桥面板、新建承台的应力情况进行判断,以及时作出相应的措施,提高了桥梁结构的稳定性和安全性。(The invention discloses a stress monitoring method for a bridge deck and a newly-built bearing platform in a bridge structure, which comprises the following steps: (1) monitoring points are distributed, and the monitoring points are uniformly distributed at the bottom of the bridge deck slab on two sides of the bridge and on two sides of the bearing platform; (2) the monitoring method and the requirement are that the bearing platform is monitored by adopting an embedded strain gauge; monitoring the bottom of the bridge deck by adopting a surface strain gauge; 1) the embedded strain gauge is used for embedding a steel bar meter in a monitoring point of the bearing platform, and counting and monitoring data of the steel bar meter with a built-in temperature sensor; 2) the surface strain gauge is arranged on the outer surface of a bridge deck plate bottom monitoring point, and data of the surface strain gauge with the built-in temperature sensor are counted and monitored; (3) and (5) processing and analyzing the data, and further judging the stress change condition of the newly-built bearing platform of the bridge structure. According to the monitoring method, the stress conditions of the bridge deck and the newly-built bearing platform are judged, and corresponding measures are taken in time, so that the stability and the safety of the bridge structure are improved.)
1. A stress monitoring method for a bridge deck and a newly-built bearing platform in a bridge structure is characterized by comprising the following steps:
(1) arrangement of monitoring points
Stress monitoring points are distributed at the bottoms of the bridge deck plates on two sides of the bridge, a stress sensor is distributed at each point in the vertical direction, and monitoring points are uniformly distributed on two sides of a bearing platform after the underpinning bearing platform is poured;
(2) monitoring method and requirements
Monitoring a newly-built bearing platform by adopting an embedded strain gauge; monitoring the bridge deck slab bottoms on two sides of the bridge by adopting a surface strain gauge;
1) embedded strain gauge
Embedding a steel bar meter in a monitoring point of a newly-built bearing platform, wherein a temperature sensor is arranged in the steel bar meter, and a calculation chip is arranged in the temperature sensor and is used for converting measured data and directly outputting physical quantity; after the embedding is finished, counting and monitoring data of a steel bar meter with a built-in temperature sensor;
2) surface strain gauge
The method comprises the following steps that a surface strain gauge is installed on the outer surface of a monitoring point at the bottom of a bridge deck slab, a temperature sensor built in the surface strain gauge can monitor the ambient temperature at the same time, and data of the surface strain gauge with the built-in temperature sensor are counted and monitored after installation is finished;
(3) data processing and analysis
And processing and analyzing the monitoring data of the steel bar meter on the newly-built bearing platform and the monitoring data of the surface strain gauge at the bottom of the bridge deck slab, and further judging the stress change condition of the newly-built bearing platform of the bridge structure.
2. The method for monitoring the stress of the bridge deck slab and the newly-built bearing platform in the bridge structure according to claim 1, wherein in the step (1), 18 stress monitoring point locations are arranged at the bottom of the bridge deck slab on one side of the bridge, and each point location is provided with 2 stress sensors in the vertical direction; 17 stress monitoring point locations are arranged at the bottom of the bridge deck plate on the other side of the bridge, and each point location is provided with 2 stress sensors in the vertical direction; and 25 monitoring points are respectively arranged on two sides of the bearing platform.
3. The method for monitoring the stress of the bridge deck slab and the newly-built bearing platform in the bridge structure according to claim 1, wherein the steel bar meter adopts a BD-GJ series intelligent steel bar meter.
4. The method for monitoring the stress of the bridge deck and the newly-built bearing platform in the bridge structure according to claim 1, wherein the installation method of the steel bar meter in the step (2) comprises the following steps: welding a steel bar meter and a steel bar at a steel bar processing field according to a designed position, or welding the steel bar meter after cutting off the measured steel bar of the steel bar net by a corresponding length at the field; aligning the central lines of the reinforcing steel bar and the reinforcing steel bar meter during welding, and then welding the connecting rods at the two ends of the reinforcing steel bar meter and the reinforcing steel bar together by a butt joint method; and the middle part of the steel bar meter is wrapped by wet cotton yarn when the steel bar meter is welded with the steel bar.
5. The method for monitoring the stress of the bridge deck slab and the newly-built bearing platform in the bridge structure according to claim 4, wherein in the embedded strain gauge in the step (2), the concrete embedding position of the steel bar meter, an experiment number, a sensor number, the embedding and installing date, the weather condition and an installer are recorded during embedding; and marking at the buried position.
6. The method for monitoring the stress of the bridge deck and the newly-built bearing platform in the bridge structure according to claim 1, wherein the installation process of the surface strain gauge comprises the following steps:
a, selecting a monitoring point;
b, mounting a mounting seat of the surface strain gauge;
c, fixing a mounting seat of the surface strain gauge on the measured object through bolts, wherein the heights of two ends of the mounting seat are balanced;
d, installing and fixing a protective cover on the outer side of the surface strain gauge;
e, reading the serial number of the surface strain gauge through a reading instrument, then adjusting the tightness of the surface strain gauge string to enable the frequency to be stabilized at about 1200HZ, and recording the frequency and the installation position together;
f, after the surface strain gauge is installed stably, zeroing the deviation value of the surface strain gauge by using a reading instrument or a computer.
Technical Field
The invention relates to the technical field of bridge monitoring, in particular to a stress monitoring method for a bridge deck and a newly-built bearing platform in a bridge structure.
Background
In order to ensure the structural safety during the bridge underpinning construction and the later operation, the stress conditions of the bridge before, during and after the construction need to be monitored, and corresponding measures are taken according to the monitored stress conditions. However, the bridge inspection mode mainly adopted in the prior art is to inspect whether the bridge meets the standard or measure regularly or not at one time, the change of the bridge is not monitored continuously, the existing inspection mode at regular intervals or at intervals has the defect of incomplete monitoring, monitoring omission occurs to bridge stress which changes chronically, and other potential safety hazards are brought.
Disclosure of Invention
The invention aims to provide a stress monitoring method for a bridge deck and a newly-built bearing platform in a bridge structure, which aims to solve the problems in the prior art, can monitor the stress of the bridge deck and the bearing platform of the bridge structure, and can take corresponding measures in time according to the monitoring result to improve the stability and the safety of a bridge.
In order to achieve the purpose, the invention provides the following scheme: the invention provides a stress monitoring method for a bridge deck and a newly-built bearing platform in a bridge structure, which comprises the following steps:
(1) arrangement of monitoring points
Stress monitoring points are distributed at the bottoms of the bridge deck plates on two sides of the bridge, a stress sensor is distributed at each point in the vertical direction, and monitoring points are uniformly distributed on two sides of a bearing platform after the underpinning bearing platform is poured;
(2) monitoring method and requirements
Monitoring a newly-built bearing platform by adopting an embedded strain gauge; monitoring the bridge deck slab bottoms on two sides of the bridge by adopting a surface strain gauge;
1) embedded strain gauge
Embedding a steel bar meter in a monitoring point of a newly-built bearing platform, wherein a temperature sensor is arranged in the steel bar meter, and a calculation chip is arranged in the temperature sensor and is used for converting measured data and directly outputting physical quantity; after the embedding is finished, counting and monitoring data of a steel bar meter with a built-in temperature sensor;
2) surface strain gauge
The method comprises the following steps that a surface strain gauge is installed on the outer surface of a monitoring point at the bottom of a bridge deck slab, a temperature sensor built in the surface strain gauge can monitor the ambient temperature at the same time, and data of the surface strain gauge with the built-in temperature sensor are counted and monitored after installation is finished;
(4) data processing and analysis
And processing and analyzing the monitoring data of the steel bar meter on the newly-built bearing platform and the monitoring data of the surface strain gauge at the bottom of the bridge deck slab, and further judging the stress change condition of the newly-built bearing platform of the bridge structure.
Preferably, in the step (1), 18 stress monitoring point locations are arranged at the bottom of the bridge deck slab on one side of the bridge, and each point location is provided with 2 stress sensors in the vertical direction; 17 stress monitoring point locations are arranged at the bottom of the bridge deck plate on the other side of the bridge, and each point location is provided with 2 stress sensors in the vertical direction; and 25 monitoring points are respectively arranged on two sides of the bearing platform.
Preferably, the reinforcing bar meter adopts a BD-GJ series intelligent reinforcing bar meter.
Preferably, the installation method of the reinforcing bar meter in the step (2) is as follows: welding a steel bar meter and a steel bar at a steel bar processing field according to a designed position, or welding the steel bar meter after cutting off the measured steel bar of the steel bar net by a corresponding length at the field; aligning the central lines of the reinforcing steel bar and the reinforcing steel bar meter during welding, and then welding the connecting rods at the two ends of the reinforcing steel bar meter and the reinforcing steel bar together by a butt joint method; and the middle part of the steel bar meter is wrapped by wet cotton yarn when the steel bar meter is welded with the steel bar.
Preferably, in the embedded strain gauge in the step (2), the concrete position where the steel bar meter is embedded, an experiment number, a sensor number, the embedding and installing date, the weather condition and an installer are recorded during embedding; and marking at the buried position.
Preferably, the installation process of the surface strain gauge comprises the following steps:
a, selecting a monitoring point;
b, mounting a mounting seat of the surface strain gauge;
c, fixing a mounting seat of the surface strain gauge on the measured object through bolts, wherein the heights of two ends of the mounting seat are balanced;
d, installing and fixing a protective cover on the outer side of the surface strain gauge;
e, reading the serial number of the surface strain gauge through a reading instrument, then adjusting the tightness of the surface strain gauge string to enable the frequency to be stabilized at about 1200HZ, and recording the frequency and the installation position together;
f, after the surface strain gauge is installed stably, zeroing the deviation value of the surface strain gauge by using a reading instrument or a computer.
Compared with the prior art, the invention has the following beneficial technical effects:
the stress monitoring method for the bridge deck and the newly-built bearing platform in the bridge structure can be used for continuously monitoring and feeding back the stress condition of the newly-built bearing platform of the bridge structure, judging the stress condition of the newly-built bearing platform according to the monitoring method and taking corresponding measures in time, so that the stability and the safety of the bridge structure are improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
FIG. 1 is a schematic view of the installation of a rebar meter;
FIG. 2 is a schematic view of the installation of a surface strain gauge;
wherein, 1, the steel bar to be tested; 2, welding a surface; 3, a steel bar meter; 4, measuring an object to be measured; 5, a protective cover; 6 surface strain gauge; 7, mounting seats; 8, bolts.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The invention aims to provide a stress monitoring method for a bridge deck and a newly-built bearing platform in a bridge structure, which aims to solve the problems in the prior art, can monitor the stress of the bridge deck and the bearing platform of the bridge structure, and can take corresponding measures in time according to the monitoring result to improve the stability and the safety of a bridge.
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.
As shown in fig. 1-2, the present embodiment provides a stress monitoring method for a bridge deck and a newly-built platform in a bridge structure, which aims to ensure the structural safety during bridge underpinning construction and later operation, monitor the stress conditions before, during and after construction, and monitor the stress conditions during underpinning.
The stress monitoring method for the bridge deck and the newly-built bearing platform in the bridge structure comprises the following steps:
arrangement of monitoring points
The method comprises the following steps of laying 18 stress monitoring point locations at the bottom of a south bridge deck slab, laying 2 stress sensors at each point location in the vertical direction, laying 17 stress monitoring point locations at the bottom of a north bridge deck slab, laying 2 stress sensors at each point location in the vertical direction, and laying 25 monitoring points on new bearing platforms at the south and north sides respectively after the new bearing platforms are poured. The stress conditions of the steel pipe during underpinning and 4 years after construction are monitored.
Second, monitoring method and requirements
The change of the structural stress of the bridge is monitored by adopting an embedded strain gauge and a surface strain gauge, and the newly-built bearing platform is monitored by adopting the embedded strain gauge; the bottoms of the south bridge deck plate and the north bridge deck plate are monitored by adopting a surface strain gauge.
(1) Embedded strain gauge
The embedded strain gauge adopts a BD-GJ series intelligent reinforcing bar meter, the BD-GJ series intelligent reinforcing bar meter uses frequency as an output signal, the strain gauge is manufactured according to a tension string principle, the anti-interference capability is strong, errors generated by long-distance conveying are extremely small, a temperature sensor is arranged in the
1) Method for mounting reinforcing bar meter
And determining monitoring points according to a design scheme, and selecting the weather without rain or snow for installation. According to the design position, the
2) Matters of attention
Carefully welding, and avoiding welding skew so as to avoid influencing the accuracy of final data.
And reading the strain timer by using a reading instrument, and displaying whether the plug is loosened or the wire is disconnected and short-circuited when the communication is overtime (with a data processor).
And thirdly, paying attention to the waterproof protection of the communication connector so as to avoid influencing the reading.
And fourthly, after all the sensors are installed, protection work must be done.
3) Observation and data recording and sorting
Firstly, the installation record of the sensor is made and filed. The contents include the concrete position where the embedded strain gauge (i.e. the steel bar meter 3) is embedded, the experiment number, the sensor number, the embedding and installation date, the weather condition and the installer.
Secondly, manufacturing a corresponding signboard, and inserting the signboard at the wiring position of the power transmission cable to mark. During each process conversion construction, a specially-assigned person needs to be arranged to take care of the construction, so as to prevent the embedded strain gauge from being damaged due to construction or natural factors.
And thirdly, manufacturing the embedded net of the embedded strain gauge according to the requirement.
And fourthly, in order to reduce the influence of the temperature on the stress data, selecting a proper time period as much as possible to monitor the stress.
(2) Surface strain gauge
The surface strain gauges 6 are manufactured according to the vibrating wire principle, are mounted on the surface of a structure, and monitor the strain changes of various structures. The built-in temperature sensor can monitor the ambient temperature simultaneously and carry out automatic compensation and correction on the temperature influence. The external string adjusting nut is specially designed, so that the installation is convenient, and the application range is enlarged. The stress-strain sensor is applied to stress-strain measurement of the concrete surface and the steel structure of a bridge, and the stress state of a measured member is fully known.
1) Working principle and calculation method
The sensing element of the vibrating string sensor is a metal steel string which is fixedly connected with a stress component of the sensor, and various physical quantities are measured by utilizing a relational expression of the natural vibration frequency of the steel string and the external tension applied to the steel string. The excitation of the vibrating string sensor is completed by an electromagnetic coil, when excitation pulse is transmitted to a magnetic core coil, the magnetic core generates a pulsating magnetic field to stir the steel string, the steel string generates an attenuated oscillation after being stirred, and the magnetic line of force cutting the magnetic core generates an attenuated sine wave at the output end of the magnetic core. The frequency of the wave measured by the receiving instrument is the natural vibration frequency of the steel string at the moment. Load of vibrating string sensor is strain quantity x 10-6X modulus of elasticity x cross-sectional area.
2) Mounting method
Firstly, surface strain gauge inspection before installation
Firstly, carefully reading the specification of the surface strain gauge 6 and the reading instrument to know the specific parameters of the surface strain gauge 6, and familiarizing with the use and operation of the reading instrument; connecting the surface strain gauge 6 with a reading instrument, and measuring and detecting whether the surface strain gauge works normally or not; check if the number of sensors and the length of the wires are correct. To determine if the sensor is damaged or lost during transport.
Installation process
a, selecting a monitoring point;
b, mounting a mounting seat 7 of the strain gauge;
c, fixing the mounting base 7 on the measured object 4 through the bolt 8, wherein the heights of the two ends of the mounting base 7 are balanced. Expansion bolts (or glue) can be used on the concrete structure.
d, mounting the protective cover 5 and fixing the protective cover by cement or marble glue.
e, reading the serial number of the surface strain gauge 6 by a reading instrument, adjusting the tightness of the string to stabilize the frequency at about 1200HZ, and recording the frequency and the installation position.
f, after the sensor is stably installed for two or three days, the offset value of the surface strain gauge 6 is zeroed by a reading instrument or a computer. The deviation value measured later is the relative zero-setting dependent variable.
3) Observation and data recording and sorting
Firstly, mounting and recording the sensor and archiving. The contents include the specific position of the surface strain gauge 6, the experiment number, the sensor number, the installation date, the weather condition, and the installer.
Secondly, manufacturing a corresponding signboard, and inserting the signboard at the wiring position of the power transmission cable to mark. In each process conversion construction, a specially-assigned person is arranged to take care of the construction, so that the surface strain gauge 6 is prevented from being damaged due to construction or natural factors.
And thirdly, in order to reduce the influence of the temperature on the stress data, a proper time period is selected as much as possible to monitor the stress.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein, and any reference signs in the claims are not intended to be construed as limiting the claim concerned.
The principle and the implementation mode of the invention are explained by applying a specific example, and the description of the embodiment is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.
- 上一篇：一种医用注射器针头装配设备
- 下一篇：具有集成特征的传感器组件