CN103344214A - 1.6-degree parabolic extralarge pier measuring and pier body linear control method - Google Patents

Abstract

A 1.6-order parabolic super large bridge pier measurement and pier body alignment control method, including the bridge pier measurement and pier body alignment control method, wherein the bridge pier measurement adopts control network measurement, the control network is a quadrilateral structure, and control points are arranged at the control network, and The control network includes the plane control network and the elevation control network. The plane control network is arranged according to the fourth-class control network, and the elevation control network is arranged according to the fifth-class elevation control network. , the linear control method includes the center positioning measurement of the hollow pier, the elevation measurement and the verticality measurement of the hollow pier. By measuring the center, elevation and verticality of the hollow pier, it provides a reference for controlling the pre-throwing height value of the elevation. The invention has simple and convenient operation process; the measurement speed of the bridge pier is fast, and the control precision is accurate; it provides a reference basis for controlling the elevation pre-throwing height, effectively controls the line shape of the pier body, improves the engineering safety factor, and has low control cost and high work efficiency.

Description

A 1.6-degree parabolic super-large bridge pier measurement and pier shape control method

technical field

The invention relates to the technical field of measurement and construction of extra-large bridge piers, in particular to a 1.6-order parabolic super-large bridge piers measurement and pier line shape control method.

Background technique

With the continuous and rapid development of the national economy, my country is currently in a period of rapid development of long-span and deep-water bridge construction. The use of advanced design and construction technology to achieve the construction goals of saving investment, shortening the construction period, and ensuring safety has always been pursued by the engineering community. . For example, the Zongmugou Bridge has a total length of 834.12 meters and is located in the "V"-shaped branch ditch of Zongmugou, Qunying Village, Zongmu Township, Baishui County, Shaanxi Province. The bridge site is located in the loess gully area, with steep terrain and deep valleys; meters, ranking first in Northwest railway bridges and second in national railway bridges; its special geographical location puts forward higher requirements for construction technology, and also increases the difficulty of construction.

The traditional bridge pier construction method is to support the formwork on the underground pile foundation, and then pour concrete inside the formwork. During the construction process, there is a lack of monitoring of the pier body, and the settlement of the pier is not considered during the construction process of the pier body. The value and vertical deformation of the pier, the construction of piers up to hundreds of meters must consider the influence of geology, wind and other related factors on the pier, otherwise it will easily lead to serious deformation of the pier in the later stage, posing safety hazards.

Contents of the invention

The technical problem to be solved by the present invention is to provide a 1.6-order parabolic super large bridge pier measurement and pier line shape control method to solve the above-mentioned shortcomings in the background technology.

The technical problem solved by the present invention adopts following technical scheme to realize:

A 1.6-order parabolic super large bridge pier measurement and pier body alignment control method, including the bridge pier measurement and pier body alignment control method, wherein the bridge pier measurement adopts control network measurement, the control network is a quadrilateral structure, and control points are arranged at the control network, and The control network includes the plane control network and the elevation control network. The plane control network is arranged according to the fourth-class control network, and the elevation control network is arranged according to the fifth-class elevation control network. , the measurement speed is fast, and the control accuracy is accurate; the pier body is a parabolic hollow structure. , to provide a reference basis for controlling the elevation pre-throwing height, and at the same time effectively control the shape of the pier body and improve the safety factor of the project.

In the present invention, the control point of the control network is set outside the construction site, and is buried in concrete, and the steel bar head engraved with "+" is buried on the top of the pile; nuclear.

In the present invention, pier body alignment control is mainly through construction measurement, and its specific steps are as follows:

1) After a section of concrete pouring is completed, use the triangular elevation method to measure the elevation of the concrete top surface, draw a cross-sectional view at the elevation according to the actual measurement elevation, and use the total station to set out the contour line to the concrete according to the coordinate method On the top surface, it serves as the control baseline for supporting the formwork of the previous segment;

2) After the formwork support of the previous section is completed, use the triangular elevation method to measure the elevation of the top surface of the formwork, and draw the cross-sectional view of the pier at the top of the formwork, and then use the total station to check the position of the formwork point by point according to the coordinate method , if there is a deviation, adjust it until it meets the requirements;

3) During the concrete pouring process, 2 plane position monitoring points are arranged on each of the 4 long sides of the pier body formwork to monitor at any time and take timely measures to correct deviations when problems are found;

4), cycle through the above steps 1) to 3);

5) Before the construction of the last section of the pier top, the elevation measurement shall be carried out simultaneously by two methods of triangular elevation and horizontal elevation steel ruler transmission, and the construction can only be carried out after the verification is correct;

6) Elevation measurement includes pier settlement and vertical deformation of pier

(1) The settlement observation of bridge piers includes the introduction and measurement methods of benchmark points

The settlement observation point adopts pre-buried steel measuring point piles, and the layout method of the settlement measuring point: set up 4 settlement observation points for each cap, the Φ20 steel bar head measuring point protrudes 3cm from the top of the cap, and the end of the cap is rounded and painted Red paint, or bend the pre-embedded steel bar out of the cap;

① Leading test of benchmark point

The benchmarking points quoted by the settlement observation points initially adopt the benchmarking points of the emergency surveying network with a point spacing of 200m. The settlement observation results obtained from the benchmark point are attributed to the elevation system of the Jingwei network; the settlement observation is measured from the nearest benchmark point, and the quoted benchmark point is checked before the survey. The height difference between adjacent benchmark points is compared with the original height difference. When the detected height difference and the original height difference are satisfied, the benchmarking point is in a stable state; otherwise, further retesting;

②Measurement method

The subsidence observation adopts the conforming leveling route method of measuring from the adjacent benchmarking point to the settlement observation point, and then closes to another benchmarking point adjacent to it, and also adopts the branch line method of directly measuring from the adjacent benchmarking point to the settlement observation point and making round-trip measurements as required ; The monitoring base point of the bridge pier is the standard benchmarking point. By measuring the elevation difference ΔH between each measuring point and the benchmarking point (base point) at time t(2) during monitoring, the standard height ht of each monitoring point at time t(2) can be calculated (2), and then compared with the height ht(1) measured at the last t(1) time, the difference Δht(1, 2) is the time period of the measuring point during t(1)～t(2) The settlement value of , namely:

Δht(1,2)=ht(2)-ht(1)

(2) Vertical deformation of bridge piers

Due to the height of the pier body of the 1.6-degree parabolic extra-large bridge, the vertical deformation of the pier due to the elastic compression and shrinkage of the concrete should be considered during the construction process. The elastic modulus and shrinkage of the concrete should be determined by testing the mechanical properties of the material. The coefficient is calculated by finite element and included in the foundation settlement during construction to finally determine the pre-throwing height of the bridge pier.

In the present invention, the elevation pre-throwing height value is the sum of the settlement value of the pier and the vertical deformation of the pier.

Beneficial effect

The mechanical tools required by the present invention are conventional tools, and the operation process is simple; and the measurement speed of the bridge pier is fast, and the control accuracy is accurate; aiming at the observation of the line shape control of the super large bridge pier body, it provides a reference for controlling the elevation pre-throwing height value, and at the same time effectively controls The linear shape of the pier body improves the safety factor of the project, with low control cost and high work efficiency.

Description of drawings

Fig. 1 is a schematic diagram of the layout of the planar control network and the relative position of the main pier in the present invention.

Fig. 2 is a schematic diagram of pier body section stakeout and compound control points in the present invention.

Fig. 3 is a front view of the arrangement of observation points for settlement of bridge piers in the present invention.

Fig. 4 is a top view of the arrangement of observation points for settlement of bridge piers in the present invention.

Among them, A, B, 1, and 2 in Figure 1 represent the plane control points, which represent the relative position to the main pier, and are used to control the plane position and elevation of the formwork on the main pier; 1, 2, 3, and 4 in Figure 4 represent the bridge pier Subsidence observation point.

Detailed ways

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

Refer to Fig. 1, Fig. 2, Fig. 3 and Fig. 4 for a 1.6-degree parabolic super large bridge pier measurement and pier body alignment control method, wherein the pier measurement adopts the control network measurement, the control network is a quadrilateral structure, and the control network is equipped with control points, and the control network includes plane control network and elevation control network. The joint measurement can effectively ensure the control measurement of the main bridge, the measurement speed is fast, and the control accuracy is accurate; the pier body is a parabolic hollow structure, and the specific construction steps of the pier body alignment control method are as follows:

1) After a section of concrete pouring is completed, use the triangular elevation method to measure the elevation of the concrete top surface, draw a cross-sectional view at the elevation according to the actual measurement elevation, and use the total station to set out the contour line to the concrete according to the coordinate method On the top surface, it serves as the control baseline for supporting the formwork of the previous segment;

2) After the formwork support of the previous section is completed, use the triangular elevation method to measure the elevation of the top surface of the formwork, and draw the cross-sectional view of the pier at the top of the formwork, and then use the total station to check the position of the formwork point by point according to the coordinate method , if there is a deviation, adjust it until it meets the requirements;

3) During the concrete pouring process, 2 plane position monitoring points are arranged on each of the 4 long sides of the pier body formwork to monitor at any time and take timely measures to correct deviations when problems are found;

4), cycle through the above steps 1) to 3);

5) Before the construction of the last section of the pier top, the elevation measurement shall be carried out simultaneously by two methods of triangular elevation and horizontal elevation steel ruler transmission, and the construction can only be carried out after the verification is correct;

6) Elevation measurement includes pier settlement and vertical deformation of pier

(1) The settlement observation of bridge piers includes the introduction and measurement methods of benchmark points

The settlement observation point adopts pre-buried steel measuring point piles, and the layout method of the settlement measuring point: set up 4 settlement observation points for each cap, the Φ20 steel bar head measuring point protrudes 3cm from the top of the cap, and the end of the cap is rounded and painted Red paint, or bend the pre-embedded steel bar out of the cap;

①Introduction of benchmarking points

The benchmarking points quoted by the settlement observation points are the emergency surveying network benchmarking points (second-class benchmarking points, point spacing 200m) at the initial stage, and after the establishment of the whole line control network, they are changed to the precise surveying network elevation benchmarking points (second-class benchmarking points, point spacing 160m) , and the settlement observation results obtained by citing the benchmark points of the emergency survey network are attributed to the elevation system of the fine survey network;

The settlement observation is conducted from the nearest benchmark point, and the reference benchmark point is checked before the survey. The check is carried out by re-testing, and the height difference between the adjacent benchmark points is compared with the original height difference value. When the detected height difference and the original height difference meet (L is the distance between two adjacent benchmark points, the unit is km), that is, the lead survey benchmark point is in a stable state; otherwise, further retest;

②Measurement method

The subsidence observation adopts the conforming leveling route method of measuring from the adjacent benchmarking point to the settlement observation point, and then closes to another benchmarking point adjacent to it, and also adopts the branch line method of directly measuring from the adjacent benchmarking point to the settlement observation point and making round-trip measurements as required ;The monitoring base point of the bridge pier is the standard benchmarking point (the elevation is known). During monitoring, by measuring the elevation difference ΔH between each measuring point and the benchmarking point (base point) at time t(2), it can be calculated that each monitoring point is at t(2) The standard height ht(2) at time, and then compared with the height ht(1) measured at the last time t(1), the difference Δht(1, 2) is the height of the measuring point between t(1)～t (2) The settlement value of the time period, namely:

Δht(1,2)=ht(2)-ht(1)

(2) Vertical deformation of bridge piers

Due to the height of the pier body of the 1.6-degree parabolic extra-large bridge, the vertical deformation of the pier due to the elastic compression and shrinkage of the concrete should be considered during the construction process. The elastic modulus and shrinkage of the concrete should be determined by testing the mechanical properties of the material. The coefficient is calculated by finite element and included in the foundation settlement during construction to finally determine the pre-throwing height of the bridge pier.

In this embodiment, the control points of the control network are set outside the construction site, and are buried in concrete, and the top of the pile is buried with a "+" steel bar head; the control points are retested every 2 months, and they are often checked and proofreading.

The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above-mentioned embodiments. What are described in the above-mentioned embodiments and the description only illustrate the principle of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have Variations and improvements are possible, which fall within the scope of the claimed invention. The protection scope of the present invention is defined by the appended claims and their equivalents.

Claims (4)

1. the especially big bridge pier of 6 parabolic types is measured and the pier shaft linear control method, comprise bridge pier measurement and pier shaft linear control method, it is characterized in that, bridge pier is measured and is adopted the control net to measure, and the control net is quadrilateral structure, and control net place is provided with the reference mark, and the control net comprises horizontal control network and vertical control network, horizontal control network is established by fourth class control screen cloth, and vertical control network is established by five contour process control screen cloths, and the net translocation is controlled with all fronts in the baseline limit of bridge pier; Pier shaft is the parabolic type hollow-core construction, its linear control method comprises hollow pier centralized positioning measurement, the measurement of higher degree and hollow pier squareness measurement, by measuring hollow pier center, elevation and hollow pier verticality, throw high value in advance for the control elevation reference frame is provided.

2. the especially big bridge pier of a kind of 1.6 parabolic types according to claim 1 is measured and the pier shaft linear control method, it is characterized in that, the reference mark of control net is arranged on outside the working-yard, and adopts concrete to bury underground, and the steel bar end that is carved with "+" is buried on the stake top underground; The reference mark every 2 months repetition measurements once, running check and check during setting-out.

3. the especially big bridge pier of a kind of 1.6 parabolic types according to claim 1 is measured and the pier shaft linear control method, it is characterized in that the linear control concrete steps of pier shaft are as follows:

1), after a sections concreting is finished, adopt the triangulated height method to measure the top of concrete elevation, according to the actual measurement absolute altitude, draw this absolute altitude place sectional drawing, and adopt total powerstation to press coordinate method, with the outline line setting-out to top of concrete, as the control baseline of the last sections template of Zhi Li;

2), after a last sections formwork support arrangement finishes, adopt the triangulated height method to measure the template elevation of top surface, and draw place, template top bridge pier cross-sectional view, adopt total powerstation to press coordinate method then, template position is checked in pointwise, if any deviation, adjust, till meeting the requirements;

3), in the concreting process, on 4 long limits of pier shaft template, respectively lay control point, 2 planimetric positions, monitoring at any time, the correction of in time taking measures of pinpointing the problems;

4), above-mentioned steps 1 is carried out in circulation)～3);

5), before the construction of last sections of Dun Ding, the measurement of higher degree adopts triangulated height and two kinds of methods of level elevation steel ruler transmission to carry out simultaneously, checks and can construct after errorless;

6), the measurement of higher degree comprises bridge pier sedimentation and bridge pier vertical deformation

(1) the bridge pier settlement observation comprises that drawing of leveling base survey and measuring method

Settlement observation point adopts the stake of pre-buried steel measuring point, sedimentation measuring point distribution method: each cushion cap is established 4 settlement observation points, and Φ 20 steel bar end measuring points stretch out cushion cap top 3cm, and cushion cap end processing rounding is also coated red paint, or embedded bar is bent cushion cap;

1. leveling base draws survey

The leveling base that settlement observation point is quoted, initial stage is adopted emergence measuring net leveling point, dot spacing is 200m, after the control net is set up completely, change accurate measurement net height journey leveling point into, dot spacing is 150～180m, and will quote settlement observation reduction as a result that emergence measuring net leveling base obtains among accurate measurement net height journey system; Settlement observation is drawn survey from nearest leveling base, check quoting leveling base before drawing survey, check and adopt the repetition measurement mode to carry out, high difference between the adjacent leveling base in front and back and former high difference are compared, when the high difference that detects and former high difference satisfy, namely draw the survey leveling base and be in steady status; Otherwise further repetition measurement;

2. measuring method

Settlement observation is adopted from contiguous leveling point and is surveyed to settlement observation point, is closed to the contact level route method of contiguous another leveling base again, also adopts as required from contiguous leveling base and directly surveys to settlement observation point and come and go the branch road collimation method of survey; Bridge pier monitoring basic point be standard water on schedule, during monitoring by recording each measuring point and leveling point (basic point) the difference of elevation Δ H in t (2) time, can calculate the standard elevation ht(2 of each monitoring point in t (2) time), the elevation ht(1 that records with t (1) time last time then) compares, difference DELTA ht(1,2) be the sedimentation value in t (1)～t (2) time period of this measuring point, that is:

Δht（1，2）=ht（2）-ht（1）

(2) bridge pier vertical deformation

Because the height of 1.6 especially big bridge pier pier shafts of para-curve, to consider the vertical deformation that bridge pier causes because of concrete elastic compression, shrinkage and creep etc. in the work progress, by the test to material mechanical performance, determine concrete elastic modulus and shrinkage and creep coefficient, through FEM (finite element) calculation, and count foundation settlement in the construction, finally determine high value of pre-throwings of bridge pier.

4. measure and the pier shaft linear control method according to claim 1 or the especially big bridge pier of 3 described a kind of 1.6 parabolic types, it is characterized in that, it is bridge pier sedimentation value and bridge pier vertical deformation sum that elevation is thrown high value in advance.

Images