How to calculate the pier crest mileage and offset of the bridge

The pier crest mileage and offset of the bridge are calculated as follows:

1. Use the two known coordinates to calculate the distance: i, and azimuth.

J2, you use two coordinate points + any point P to calculate the mileage to form 3 points.

3. Connect the 3 points to form a triangle.

Set the two coordinate points of the reverse calculation of coordinates to the bottom of the triangle.

4. Use Helen.

The algorithm finds the height of the triangle: (offset); Dip down to the bottom m point of the triangle. Advantages of Helen's algorithm: polar coordinates.

orientation. The formula will not be invalid (don't understand Helen please).

5. Then use the inverse cosine algorithm to find the distance from the starting point of your coordinate backcalculation to the point of perpendicular m: t.

6. Use "j" and "t" to import coordinates to obtain the offset x (left-; Right +) 7, specific arithmetic test: (outside the line point x - (reverse calculation starting point x + (t*cos(j))) cos(j-90).

Or (outside the line point y-(reverse calculation starting point y+(t*sin(j))) sin(j-90) choose one of the two.

8. You can also get the coordinates of point m with the correct calculation of coordinates!

This you have to see whether you are a railway or a highway, the railway is based on the center line of the left line to calculate the mileage and offset, the specific size depends on the structural drawing, the mileage is in the plan, the highway is to calculate the mileage and offset by the center line of the line.

When calculating the mileage at the top of the bridge, you have to look at the map to calculate, don't be blind. Be careful with its inclination (depending on what kind of bridge you have).

The deviation is three to five centimeters.

Single-column piers are adopted, and the spacing between columns is generally maintained at more than 4-6m. In bridges with two spans and more than two spans, except for the abutments that connect with the embankment at both ends, the rest of the intermediate support structures are called piers, and it is recommended to change to:

The intermediate support structure of a multi-span bridge is called a pier. Bridge piers are divided into solid piers, column piers, and row frame piers. According to the plane shape, it can be divided into rectangular pier, tip pier, circular pier, etc. The materials of the construction piers can be wood, stone, concrete, reinforced concrete, steel, etc.

The method of determining the spacing of the dry beams of the main brother of the bridge is as follows:

It is optimized from all aspects such as the amount of economical materials, the reduction of on-site engineering as much as possible, and the hoisting weight of the monolithic girder.

1) The spacing of the main beam of the highway simply supported T beam should be adopted.

2) It is more economical to increase the spacing and reduce the number of pieces.

3) If the spacing is too large, pay attention to the force on the flange plate.

4) The spacing of the 40m standard diagram is small, which is mostly used in the actual design.

5) The width of the prefabricated slab is average; Standard design takes.

The main beam refers to the beam that supports various loads in the superstructure and transmits them to the piers and platforms.

The main beam spacing refers to the transverse horizontal spacing between two main beams.

Generally speaking, according to the grade of the bridge designed, for example, the bridge design grade is a level, and the net width of the lane is for, and then according to the number of lanes that need to be designed, such as a two-way dual carriageway, then the width of the bridge deck is now required to be 7m, plus the width of the railing.

Generally, the width of the railing is m or, take it here, then the current bridge width is 10m, and then you can determine the number of pieces of the T beam, because the general width of the T beam has, so you can take the length of the T beam is 2m. Then the number of pieces of T-beam required is 5.

Specifically, it should be determined according to national norms, and the standard span approved by the state is and 160 meters.

The upper support beam bridge (or 40 meter steel girder bridge) with a span of less than or equal to 32 meters is commonly erected by railway bridge erection rigs, for which the single-track concrete bridge divides a hole beam into two pieces with a longitudinal joint, and the weight of each beam piece is limited. If the span is equal to or greater than 48 meters, they are all steel truss girders. In order to improve the speed and quality of construction site assembly, the rods and gusset plates should be interchangeable in terms of design size and site hole accuracy.

Therefore, when formulating the main dimensions and detailed structures, it is necessary to consider the process equipment and technical level of the factory. Stone arch bridges, culverts, piers, yard caisson foundations, etc. also have standard designs, but because most of them are not suitable for factory manufacturing, the benefits from design standardization are slightly inferior.

10mm, you can go to the evaluation standard to check.

When designing the bridge, in order to make the two sides of the beam evenly stressed when the train is running, the bridge working line should be as close as possible to the center line of the line, so the bridge pier offset is set. The pier offset is designed to reduce the span and the size of the substructure.

In new construction, due to the use of lightweight aggregate concrete.

The self-weight of the bridge can be reduced, so the span can be lengthened, the pier spacing can be increased, the span can be reduced, and the size of the substructure can be reduced without increasing the dead load of the original design. In the reconstruction project, the use of light aggregate concrete can make the bridge widen the bridge deck or improve the bearing capacity without reinforcing the substructure and the foundation acre liquid foundation.

In the process of designing the bridge, in order to make the beam evenly stressed on both sides of the train running, the bridge working line should be as close as possible to the center line of the line, so when the beam is arranged, the turning point of the working line should be moved to the outer side of the middle line of the line for a distance E, and this distance is called "pier offset". The offset e is generally half of the length of the beam string.

1. Before the construction of the pier platform, the concrete on the top surface of the foundation within the construction scope should be chiseled, and the loose layer and stone chips on the surface should be cleaned up to the pier stud of the sectional construction, and the joints should also be chiseled and cleaned.

2. When the pier stud height exceeds 10 meters, it can be constructed in sections, and the height of the segments should be determined according to the concrete construction conditions and the length of the steel bar. During the construction of the previous section, the concrete strength of the poured section should not be lower than Pascal;

3. Before the template is installed, the axis and edge line of the pier stud should be released on the top surface of the foundation, and the plane position and verticality of the first section of the template installation should be strictly controlled for the pier stud of the sub-section construction. In the process of installation, the formwork should ensure the verticality of the pier stud by measuring and monitoring measures, and there should be temporary measures to prevent overturning, and its wind resistance stability should be considered for the pier body formwork with high pier and large wind;

4. Measures should be taken to shorten the interval between the pier stud and the cushion cap for pouring concrete, and the intermittent period should not be greater than 10 cm;

5. When pouring concrete, the arrangement of collusion and chute should be convenient for paving and vibrating, and the working area should be clearly divided. After the concrete pouring is completed, it should be cured in time, and the curing time shall not be less than 7 cm.

According to the beam spacing range given by the main beam in the calculation (if any, then according to the width of the bridge deck, determine the number of pieces of the required beam, determine the spacing of the beam, and this spacing must be in the range of the beam spacing, otherwise it can not meet the requirements of the calculation.