What is Load Transverse Distribution? How do I determine the load transverse distribution factor?

The lateral distribution of the load refers to how the vehicle load acting on the bridge is distributed among the main beams, or how the main beams share the live load of the vehicle. Calculation of the transverse distribution of loads.

The load to be targeted is mainly the live load, so it is also called the live load transverse distribution (this is the value to be obtained when the longitudinal beam calculation is done later).

The load transverse distribution coefficient refers to the percentage of the road vehicle load distributed among the transverse main girders of the bridge. In ordinary simply supported bridges, it is related to the connection mode (hinged or rigidly connected) between the main beams, whether there are internal beams (and their number), the bending stiffness and torsional stiffness of the section, and the position of the vehicle load on the bridge.

It is a complex spatial structure problem, which is often simplified to a plane problem in bridge design and the load transverse distribution coefficient is referenced. The load transverse distribution coefficient is the final numerical result obtained by summing the vertical scale value of the corresponding influence line of the load according to the most unfavorable position of the load on the basis of the load transverse distribution influence line.

The load transverse distribution theory plays an important role in the design of beams and bridges. The calculation methods of the transverse distribution coefficient of highway beam bridge load mainly include: beam lattice method, plate system method and beam system method.

The beam lattice method also includes the eccentric pressure method, the modified eccentric pressure method, the elastic support continuous beam method and the generalized beam lattice method. The plate system method includes the hinged plate (beam) method and the rigid plate (beam) method; The beam system method is comparable to the orthotropic plate method (G-M method).

The lateral distribution of the load means that the vehicle load acting on the bridge is distributed among the main beams, or that the main beams share the live load of the vehicles.

Transverse distribution coefficient: when the unit load is arranged on the transverse influence line of the load according to the most unfavorable position of the transverse load, the maximum value of the transverse load assigned to each piece of main beam is m, which is m. Represents the maximum load proportion of the main beam in the transverse distribution, which is called the load transverse distribution factor.

Based on the lateral distribution law of the deflection of the main girder to determine the transverse distribution of bridge load, considering the natural frequency, mode shape and modal mass of the calculation mode of the bridge structure, a method for calculating the load transverse distribution coefficient of bridges of various structural forms is proposed, that is, the modal parameter method.

CentralizedLoadm=1 4FL, uniform load m=1 8ql2.

Concentrated load, which refers to the load of the reaction force acting on the rise of a point, is called the concentrated load, and its unit is thousand Newtons.

For example, structural columns.

Arranged on the beam, then the load of this state point Sun Xiaoyuan is called a concentrated load.

Epilogue. Evenly distributed load, generally expressed in q, is simply evenly distributed.

The forces (loads) on the structure and the loads at each point under the action of uniform loads are equal. Its unit is generally cattle per metre (n m) or cattle per square meter (n m 2).

Sometimes pressure is also used as a uniform load. For example, the gravity of the fixed beam is the uniform load (linear uniform load), or the pressure on the object is also the uniform load on the pressure surface (surface uniform load).

Refer to the base value:

Dead load value: Snow load value: kn

Wind pressure value: kn

Self-weight of the roof canopy: kn

The wz value of the original steel beam: this talk about the wz=274c

Adjusted steel beam wz value: wz=265c

Allowable stress value of beam bending: 【

1. Refer to the formula:

Flexural section modulus: wz=d*(h squared) 6 Steel beam bending stress strength: ómax=(mmax) wz) [Maximum bending moment in the beam: mmax=(1 16)*p*l Steel beam force point: p

Length between fulcrums at both ends of the beam: l

Second, the original steel beam bending stress Johnson Nadu check:

The total load value of the steel beam: area * parameter value = 6*

P= mmax=(1 16)*p*l mmax= (1 16)* max=(mmax) wz) [max=(3rd power) (274*10 to the minus 6th power)=

3. Check the bending stress strength of the steel beam after adjustment

The total load value of the steel beam: area * parameter value = 6*

p= mmax=(1 16)*p*l mmax= (1 16)* max=(mmax) wz) [max=(to the 3rd power) (265*10

of minus 6 power) =

Concentrated load, which refers to the load of the reaction force acting on a point, is called the concentrated load, and its unit is thousand Newtons.

Concentrated load: Anyway, the load acting on a point is called concentrated load, for example, if the structural column is arranged on a beam, then the load at this point is called a concentrated load.

Uniform load: The load that acts continuously on a large area on the surface of the component, cannot be regarded as a concentrated load, and the load with the same magnitude and direction of any two loads is called a uniform load. For example, the self-weight of a wall. Its unit is kilonewtons per meter.

Method for calculating concentrated line loads.

Concentrated line load = permanent load (self-weight of reinforced concrete + self-weight of formwork timber) partial coefficient + construction uniform live load partial factor.

The self-weight of reinforced concrete = the interception and bending area of the beam (m2) 26kn m3 (26kn m3 is the specific gravity of reinforced concrete converted into kn m3 as a unit, and the specific gravity of steel judged stuffy concrete is 26kn m3 when calculating the concentrated line load. ）

The self-weight of the formwork = the perimeter of the beam section formwork (m) The value taken when calculating the concentrated line load is.

Construction uniform distribution of live load = beam width m 3kn m2

Partial coefficients. The partial factor of permanent load is taken; The partial coefficient of the construction uniform distribution of live load is taken.

Example: The height of the chain beam is 700, and the beam width is 700

The beam height is 1000, and the beam width is 500

The beam height is 900, and the beam width is 600

Argumentation is needed.

The action of the load on the transverse movement of the beam, the magnitude of the vertical value of the action on a fixed point (shear force, bending moment), the connection of the points formed.

Load Bai Lateral Distribution Influence Line: The load moves on the DU transverse of the beam, zh

The magnitude of the vertical scaled value of the action on a certain DAO fixed point (shear back force, bending moment), and the connection of the points formed.

Loads refer to the external forces and other factors that cause internal forces and deformations of a structure or component. Or customarily refers to the various direct effects exerted on the engineering structure to make the engineering structure or components produce effects, the common ones are: structural self-weight, floor live load, roof live load, roof ash load, vehicle load, crane load, equipment dynamic load and natural loads such as wind, snow, ice, waves, etc.