CN101241522A - Method for determining stayd-cable bridge construction intermediate state utilizing unit original size - Google Patents

Abstract

The present invention method of determining cable stayed bridge construction middle state using original size of the component unit, belonging to cable stayed bridge mounting calculating technology, in particular a method of determining cable stayed bridge construction middle state using original size of the component unit. The method is 1. Calculating original size of cable stayed bridge component unit of the bridge frame, 2. Processing mounting calculation, mounting the unit original size being identical to the original size of the cable stayed bridge state unit, 3. If overstressing, adjusting the middle tensioning of the force of the stay cables, after being mounted, adjusting cable to whole bridge to eliminate the impact of creep and shrinkage of concrete, 4. Obtaining original size of new cable stayed bridge unit by deduction the structure forcing impact of the unit size of the cable stayed bridge of the step 3, 5. Repeated cycle steps 2, 3, 4 until the structure force of the step 4 being identical to the upper cycle step 4, iterated over, obtaining the middle state. The invention has less preliminary data, quick iteration speed, high strain force and high operating efficiency.

Description

Utilize the unit original size to determine the method for CONSTRUCTION OF CABLE-STAYED BRIDGE intermediateness

Technical field

Cable-stayed bridge of the present invention is installed computing technique, is specially and utilizes the unit original size to determine the method for CONSTRUCTION OF CABLE-STAYED BRIDGE intermediateness.

Background technology

The installation evaluation work of cable-stayed bridge is different with the computing method of continuous beam, continuous rigid frame.Continuous beam, continuous rigid frame can carry out the construction and installation analog computation earlier, run the inspection calculation of load then according to the last Cheng Qiao that installs after calculating.Cable-stayed bridge is because its intrinsic characteristic must be carried out to bridge calculating earlier, then the appropriate operation by finding can be installed to last one-tenth bridge state someway.Existing method is the most famous with the analytic approach that falls back, and other also have formal dress trial and error procedure or the like method, and data volume is big, speed of convergence is slow, it is poor to adapt to on-the-spot changing capability but the common ground of these methods is preparation.If such as after install to calculate finishing, construction procedure will change, the analytic approach that falls back need be walked whole circulation one time again, generally needs several days even the workload in week more than one, and this must cause operating efficiency low.

Summary of the invention

The objective of the invention is at above-mentioned present situation, aim to provide a kind of method that can directly determine the CONSTRUCTION OF CABLE-STAYED BRIDGE intermediateness.

The implementation of the object of the invention is, utilizes the unit original size to determine the method for CONSTRUCTION OF CABLE-STAYED BRIDGE intermediateness, and concrete steps are:

1) is calculated to be the cable-stayed bridge member unit size and the internal force state of bridge state, calculates the original size of the later cable-stayed bridge member unit of distortion that deduction internal force causes

2) carry out conventional cable-stayed bridge calculating is installed, when the suspension cable unit puts stretch-draw in place, according to the relational expression Δ T of suspension cable original length variable quantity and Suo Li variable quantity ₁₂=(S ₁₀-S ₂₀)/(S ₂₀/ EA-ε) the unit original size is installed to such an extent that become the original size unanimity of bridge state cell with the cable-stayed bridge that step 2 is calculated, is called suspension cable and puts in place,

3) before suspension cable puts in place by adjusting the interior card pulling force of suspension cable, allow main beam structure stress remain within the allowed band, can not make girder stress surpass permissible value up to later construction procedure, again with inclined guy cable stretching to original size with to become the bridge state the same

4) set by step 2 and 3 install after, for the bridge that concrete shrinkage and creep is arranged, need carry out full-bridge and transfer rope, make structural internal force and to become the bridge status architecture in full accord,

5) with the influence of step 4 cable-stayed bridge member unit size deduction structural internal force, obtain new cable-stayed bridge member unit original size,

6) the new original size of cable-stayed bridge member unit that obtains with step 5, repetitive cycling step 2,3,4, the structural internal force state consistency that a structural internal force that obtains up to step 4 and a last circulation step 4 obtain, iteration finishes, the intermediateness of must constructing.

The present invention has following advantage:

1, prepares data volume less than half of the analytic approach that falls back;

2, iteration speed is than very fast, in same data volume and get rid of under the manual situation, speed of convergence is 2 times of analytic approach of falling back, the iterative loop of analytic approach needs manual operations because of falling back, so the analytic approach that generally the falls back iterative loop time once for a couple of days, and with the method iterative loop once at most as long as 1 day;

3, because iterative convergence speed is fast, therefore can react rapidly, can improve operating efficiency greatly the changeable situation in scene.

Figure of description

Fig. 1 is a view before the inclined guy cable stretching

Fig. 2 is a view behind the inclined guy cable stretching

Embodiment

Principle of the present invention is: by the analysis to Construction of Cable-Stayed Bridges, can find suspension cable when initiatively not adjusting, though the Suo Lihui of suspension cable changes, the original size of suspension cable can not change.Only when initiatively adjusting suspension cable, the original size of suspension cable just can change, and the variable quantity of original size and Suo Li variable quantity are directly proportional.Therefore after inclined guy cable stretching puts in place, promptly to become all no longer adjust before the bridge after, its original length and become the bridge original length equal.Suo Li in the time of can determining that inclined guy cable stretching puts in place according to the back suspension cable original length that puts in place with the principle that becomes bridge suspension cable original length to equate, thus directly determine the CONSTRUCTION OF CABLE-STAYED BRIDGE intermediateness.Original size refers to physical dimensions such as length after member deduction internal force produces distortion, curvature.

The relation derivation of suspension cable original length variable quantity and Suo Li variable quantity is as follows.Show configuration state 1 as Fig. 1: the geometrical length S of suspension cable ₁, zero stress original length S ₁₀, rope area A, the elastic modulus E of suspension cable, Suo Li T ₁By becoming state 2: the geometrical length S of rope with lifting jack active stretch-draw suspension cable ₂, zero stress original length S ₂₀, Suo Li T ₂=T ₁+ Δ T ₁₂

State 1: $S_1=S_{10}+\frac{T_1\·S_{10}}{\mathrm{EA}}---\left(1\right)$

State 2: $S_2=S_{20}+\frac{T_2\·S_{20}}{\mathrm{EA}}---\left(2\right)$

Formula (2)-Shi (1) also ignores the second order amount and gets:

$S_2-S_1=S_{20}-S_{10}+\frac{\mathrm{\Δ}{T}_{12}\·S_{20}}{\mathrm{EA}}$

Be located at D, E at 2 and apply a pair of reverse unit force along the DE direction, 2 geometric positions along the DE direction of D, E change and are made as ε, then:

$S_{20}-S_{10}+\frac{{\mathrm{\ΔT}}_{12}\·S_{20}}{\mathrm{EA}}=\mathrm{\Δ}{T}_{12}\·\mathrm{\ϵ}$

${\mathrm{\ΔT}}_{12}=(S_{10}-S_{20})/(S_{20}/\mathrm{EA}-\mathrm{\ϵ})---\left(3\right)$

Formula (3) has illustrated when outer load and structural system are constant, the corresponding relation that the adjustment of suspension cable zero stress original length and Suo Li change.The zero stress original length of suspension cable DE is adjusted to effect and the DE cable stretching power increase Δ T of S20 to total from S10 ₁₂Be equal to.Formula (3) has been arranged afterwards, when install calculating, can calculate stretch-draw time how many Suo Li, the zero stress original length of suspension cable so just is mounted to suspension cable the same with the original size that becomes the bridge state with to become bridge zero stress original length equal.

Concrete steps of the present invention are as follows:

1) is calculated to be the cable-stayed bridge member unit size and the internal force state of bridge state, calculates the original size of the later cable-stayed bridge member unit of distortion that deduction internal force causes

2) carry out conventional cable-stayed bridge calculating is installed, when the suspension cable unit puts stretch-draw in place, according to the relational expression Δ T of suspension cable original length variable quantity and Suo Li variable quantity ₁₂=(S ₁₀-S ₂₀)/(S ₂₀/ EA-ε) the unit original size is installed to such an extent that become the original size unanimity of bridge state cell with the cable-stayed bridge that step 2 is calculated, is called suspension cable and puts in place,

3) before suspension cable puts in place by adjusting the interior card pulling force of suspension cable, allow main beam structure stress remain within the allowed band, can not make girder stress surpass permissible value up to later construction procedure, again with inclined guy cable stretching to original size with to become the bridge state the same

4) set by step 2 and 3 install after, for the bridge that concrete shrinkage and creep is arranged, need carry out full-bridge and transfer rope, make structural internal force and to become the bridge status architecture in full accord,

5) with the influence of step 4 cable-stayed bridge member unit size deduction structural internal force, obtain new cable-stayed bridge member unit original size,

6) the new original size of cable-stayed bridge member unit that obtains with step 5, repetitive cycling step 2,3,4, the structural internal force state consistency that a structural internal force that obtains up to step 4 and a last circulation step 4 obtain, iteration finishes, the intermediateness of must constructing.

Claims (2)

1, utilize the member unit original size to determine the method for CONSTRUCTION OF CABLE-STAYED BRIDGE intermediateness, it is characterized in that concrete steps are:

1) is calculated to be the cable-stayed bridge member unit size and the internal force state of bridge state, calculates the original size of the later cable-stayed bridge member unit of distortion that deduction internal force causes

2) carry out conventional cable-stayed bridge calculating is installed, when the suspension cable unit puts stretch-draw in place, according to the relational expression Δ T of suspension cable original length variable quantity and Suo Li variable quantity ₁₂=(S ₁₀-S ₂₀)/(S ₂₀/ EA-ε) the unit original size is installed to such an extent that become the original size unanimity of bridge state cell with the cable-stayed bridge that step 2 is calculated, is called suspension cable and puts in place,

3) before suspension cable puts in place by adjusting the interior card pulling force of suspension cable, allow main beam structure stress remain within the allowed band, can not make girder stress surpass permissible value up to later construction procedure, again with inclined guy cable stretching to original size with to become the bridge state the same

4) set by step 2 and 3 install after, for the bridge that concrete shrinkage and creep is arranged, need carry out full-bridge and transfer rope, make structural internal force and to become the bridge status architecture in full accord,

5) with the influence of step 4 cable-stayed bridge member unit size deduction structural internal force, obtain new cable-stayed bridge member unit original size,

6) the new original size of cable-stayed bridge member unit that obtains with step 5, repetitive cycling step 2,3,4, the structural internal force state consistency that a structural internal force that obtains up to step 4 and a last circulation step 4 obtain, iteration finishes, the intermediateness of must constructing.

2, the method for utilizing the member unit original size to determine the CONSTRUCTION OF CABLE-STAYED BRIDGE intermediateness according to claim 1 is characterized in that the original size of cable-stayed bridge member unit refers to the physical dimension of member unit after deduction internal force produces distortion.