CN-115374505-B - Single-box three-chamber box girder hydration temperature gradient design method and system based on dot matrix

CN115374505BCN 115374505 BCN115374505 BCN 115374505BCN-115374505-B

Abstract

The invention provides a single-box three-chamber box girder hydration temperature gradient design method and system based on a dot matrix type, wherein the arrangement of experimental measuring points of a hydration heat temperature field of the method is sufficient, the most unfavorable temperature distribution of a structure can be comprehensively reflected, temperature gradient values at different positions in different time can be calculated, y=a (t) x 2 +b (t) x+c (t) fitting is carried out on the vertical temperature gradients of a side web and a middle web of a box girder, a three-fold line model is adopted on an obtained vertical temperature gradient time course curve, so that the vertical temperature gradient at any position in any time in a hydration heat stage is obtained, y=a (t) x 2 +b (t) x+c (t) fitting is also adopted on a distribution curve of a top plate, and a two-fold line model is adopted on the obtained horizontal temperature gradient time course curve, so that the horizontal temperature gradient value at any position in any time in the hydration heat stage is obtained, and accurate calculation of the box girder temperature gradient value is facilitated, and reference is provided for temperature distribution evaluation and crack resistance of a bridge section of a follow-up type bridge.

Inventors

REN WENHUI
ZHANG FENG
LIU JUNQUAN
KOU YUE
MA YANYANG
ZHANG XIUFENG
YANG LEZHI
ZHU LIANG

Assignees

山东大学

Dates

Publication Date: 20260508
Application Date: 20220720

Claims (7)

1. The single-box three-chamber box girder hydration temperature gradient design method based on the dot matrix is characterized by comprising the following steps: Collecting real-time temperature data of the section of the model concrete box girder and meteorological data of the environment; Drawing a two-dimensional temperature distribution cloud chart and a solar radiation and wind speed and maximum temperature difference scatter chart of the section of the concrete box girder at different moments of time variation based on the acquired real-time temperature data of the section of the concrete box girder and meteorological data of the environment; According to the temperature distribution cloud pictures at different moments, a distribution rule of temperature change along with time at any position of a cross section of the box girder is obtained, a plurality of characteristic position points are selected, and the temperature change of the characteristic position points is analyzed to obtain a hydrothermal temperature time course curve; according to the hydrothermal temperature distribution cloud pictures of the characteristic points at different moments, calculating vertical temperature gradients and transverse temperature gradients at different moments, and fitting a vertical temperature gradient time interval formula and a transverse temperature gradient time interval formula; according to the vertical temperature gradient time course curve, a triple line model is established, and a vertical temperature gradient time course formula of the edge web and the middle web is provided; the edge web time course formula is that, in the formula, t is the time (unit: h) after the box girder is poured: ; substituting a (t), b (t) and c (t) into And obtaining a vertical temperature gradient at any position at any moment in the hydration heat stage, and drawing a theoretical yearly gradient and an actual temperature gradient three-dimensional cloud picture.
2. The lattice-based single-box three-chamber box girder hydration temperature gradient design method according to claim 1, wherein a wind speed sensor, a wind direction sensor and a solar radiation sensor are arranged at the top and the bottom of the box girder to measure meteorological data of the environment where the box girder is located.
3. The method for designing the hydration temperature gradient of the single-box three-chamber box girder based on the dot matrix type according to claim 1, wherein a local coordinate system is established on the section of the concrete box girder, the coordinates of each temperature measuring point are determined, and the dot matrix coordinate index of the temperature sensor is established.
4. The lattice-based single-box three-chamber box girder hydration temperature gradient design method according to claim 1, wherein a plurality of characteristic points on a box girder top plate, a box girder bottom plate and a box girder web are selected, and hydration heat time-course curves of the characteristic point positions are obtained by analyzing temperature change conditions of the top plate, the box girder bottom plate and the box girder cross section according to hydration heat temperature actual measurement values.
5. The lattice-based single-box three-chamber box girder hydration temperature gradient design method according to claim 4, wherein measured data of a box girder top plate part, a box girder bottom plate part, a web plate part and a box girder cross section integral temperature measuring point 96h are selected respectively, average temperatures of all parts are calculated by taking an average value, the average temperatures are averaged to obtain cross section temperatures, average temperatures of all times are subtracted from average temperatures of an in-mold mode to obtain average temperatures of all areas, and a time course curve of the temperature rise of all areas is drawn.
6. The lattice-based single-box three-chamber box girder hydration temperature gradient design method according to claim 5, wherein hydration heat temperature rise analysis is carried out on two webs at the left side, the vertical temperature gradient is obtained by subtracting the vertical minimum temperature from the temperature of each measuring point, and a curve of the vertical temperature gradient of each measuring point along with the time is drawn.
7. The single-tank three-chamber box girder hydration temperature gradient design system based on the dot matrix, specifically executing the single-tank three-chamber box girder hydration temperature gradient design method based on the dot matrix as claimed in any one of claims 1 to 6, is characterized by comprising the following steps: the sensors are used for collecting real-time temperature data of the section of the model concrete box girder and meteorological data of the environment where the model concrete box girder is located; The data processing center is used for drawing a two-dimensional temperature distribution cloud picture and a solar radiation and wind speed and maximum temperature difference scatter diagram of the cross section of the concrete box girder at different moments along with the time change based on the acquired real-time temperature data of the cross section of the concrete box girder and the meteorological data of the environment; According to the temperature distribution cloud pictures at different moments, a distribution rule of temperature change along with time at any position of a cross section of the box girder is obtained, a plurality of characteristic position points are selected, and the temperature change of the characteristic position points is analyzed to obtain a hydrothermal temperature time course curve; the data calculation center is used for calculating vertical temperature gradients and horizontal temperature gradients at different moments according to the hydrothermal temperature distribution cloud pictures of the characteristic points at different moments respectively, and fitting a vertical temperature gradient time interval formula and a horizontal temperature gradient time interval formula.

Description

Single-box three-chamber box girder hydration temperature gradient design method and system based on dot matrix Technical Field The disclosure relates to the technical field of concrete hydration heat design, in particular to a single-box three-chamber box girder hydration temperature gradient design method based on dot matrix. Background The statements in this section merely provide background information related to the present disclosure and may not necessarily constitute prior art. A large amount of heat is generated when cement and water are mixed. Because of the rapid heat exchange on the concrete surface, a large temperature difference is formed between the inside and the outside of the concrete. The bridge structure has different temperature states, different temperature deformation is caused, and the concrete generates great temperature stress due to the different deformation of each part, so that the concrete structure is easy to crack due to hydration heat in early concrete pouring. The current research on hydration heat is mainly focused on piers and deck boards. However, the structure and the thermal boundary condition of the cross section of the single-box multi-chamber box girder are different from those of bridge piers and bridge decks, the top plate, the bottom plate and the web of the box girder have different hydration heat distribution characteristics, the hydrothermal research of the cross section of the box girder in the prior art is mainly realized by combining the actual measurement data of characteristic points with numerical simulation, the interior of the cross section of the box girder is hollow and has complex boundaries, the factors influencing the hydrothermal research are more, the temperature development rule of the structure is still difficult to accurately predict by correcting a finite element model through concrete thermal parameters, the position selection of a measuring point is only based on the actual measurement data of the characteristic points along the depth direction or the height direction, the most unfavorable temperature distribution of the structure cannot be comprehensively reflected, and no effective scheme exists for the dot matrix temperature field research of the cross section of the single-box three-chamber girder. Disclosure of Invention In order to solve the problems, the present disclosure provides a single-box three-chamber box girder hydration temperature gradient design method based on dot matrix. The method can fully consider that the top plate, the bottom plate and the web plate have different hydration heat distribution characteristics, so that temperature gradient values at different positions at different times can be calculated. According to some embodiments, the present disclosure employs the following technical solutions: a single-box three-chamber box girder hydration temperature gradient design method based on a dot matrix comprises the following steps: Collecting real-time temperature data of the section of the model concrete box girder and meteorological data of the environment; Drawing a two-dimensional temperature distribution cloud chart and a solar radiation and wind speed and maximum temperature difference scatter chart of the section of the concrete box girder at different moments of time variation based on the acquired real-time temperature data of the section of the concrete box girder and meteorological data of the environment; According to the temperature distribution cloud pictures at different moments, a distribution rule of temperature change along with time at any position of a cross section of the box girder is obtained, a plurality of characteristic position points are selected, and the temperature change of the characteristic position points is analyzed to obtain a hydrothermal temperature time course curve; And respectively calculating the vertical temperature gradient and the horizontal temperature gradient at different moments according to the hydrothermal temperature distribution cloud pictures of the characteristic points at different moments, and fitting a time interval formula of the vertical temperature gradient and the horizontal temperature gradient. According to other embodiments, the present disclosure employs the following technical solutions: the sensors are used for collecting real-time temperature data of the section of the model concrete box girder and meteorological data of the environment where the model concrete box girder is located; The data processing center is used for drawing a two-dimensional temperature distribution cloud picture and a solar radiation and wind speed and maximum temperature difference scatter diagram of the cross section of the concrete box girder at different moments along with the time change based on the acquired real-time temperature data of the cross section of the concrete box girder and the meteorological data of the environment; According to the temperature distributio