CN203080400U - Extra-large span suspension bridge with uniparted hyperboloid space cable net main cables - Google Patents

Abstract

The utility model provides an extra-large span suspension bridge with uniparted hyperboloid space cable net main cables. A straight line characteristic of a uniparted hyperboloid is used, a vertical parallel cable system of a traditional suspension bridge is improved, heavy centralized cables are changed into scattered space steel wire cables, a plurality of steel wire cables are arranged in a cross mode in space, cross nodes of the uniparted hyperboloid space cable net main cables are fixed to form a uniparted hyperboloid form space cable system, oval steel structure strengthening ring beams are arranged, hanging rods and reinforcing beams are installed, door type rigid central buckles are arranged, and the extra-large span suspension bridge with the uniparted hyperboloid space cable system is built. The extra-large span suspension bridge with the uniparted hyperboloid space cable net main cables has the advantages of being good in span ability, large in rigidity of space structures, high in contortion frequency ratio, good in wind resistant stability, and the like. The extra-large span suspension bridge with the uniparted hyperboloid space cable net main cables is capable of fundamentally solving the problem of wind resistant stability of large-span suspension bridges, and is applicable to construction of cross-sea island connection and construction of extra-large span strait suspension bridges with a length in a range from 3000m to 5000m.

Description

A super-long-span suspension bridge with single-leaf hyperboloid space cable-net main cables

technical field

The utility model belongs to the field of civil engineering, and relates to a construction technology of a long-span suspension bridge, in particular to a super-large-span suspension bridge with a single-leaf hyperboloid space cable net main cable.

Background technique

Suspension bridge is the type of bridge with the strongest spanning capacity in the world, and bridges with a span of more than 1,000 meters are basically suspension bridges. In 1998, Japan had built the Akashi Kaikyo Suspension Bridge with a span of 1991 meters, ranking first in the world. In 2009, my country has built the Zhoushan Xihoumen Suspension Bridge with a span of 1650 meters, ranking second in the world. In 2010, the Italian government planned to spend 11.7 billion US dollars to build a suspension bridge over the Strait of Messina with a main span of 3,300 meters in order to connect the traffic between mainland Italy and Sicily. The construction of the Qiongzhou Strait Bridge has been a dream of the Chinese people for many years. In 2012, the Chinese government planned to spend 140 billion yuan to build a large-span suspension bridge with a main span of about 3,500 meters in the Qiongzhou Strait, so as to connect mainland China and Hainan Island. transportation. At present, there is an upsurge in the construction of cross-sea and island bridges in the world. In order to meet the navigation requirements of two 500,000-ton ships and to avoid the construction of expensive deep-sea deep-water foundations, it is necessary to build a 3,000-5,000-meter-span strait. bridge.

The most common form of cable arrangement for suspension bridges is the parallel cable system, which has two vertically parallel cable plane systems formed by the main cable and the suspender. The traditional vertically parallel cable system suspension bridge has the characteristics of strong vertical bearing capacity and can bear the superstructure weight and vehicle load of the suspension bridge with a span of 3000-5000 meters. However, due to the poor lateral stiffness of the vertically parallel cable system, the resistance Poor torsional stiffness cannot meet the wind resistance stability requirements of 3000-5000m long-span channel suspension bridges.

With the continuous improvement of the design and construction level of suspension bridges, the span records of modern suspension bridges are constantly being refreshed, and the structure of suspension bridges is becoming softer and softer. The main problem brought about by the large increase in the span of suspension bridges is the sharp drop in the spatial stiffness of the suspension bridge structure. The suspension bridge with a vertically parallel cable system is very sensitive to the effect of wind loads, and the problem of wind resistance has become increasingly prominent. The impact of wind resistance is more important, and the most critical factor affecting the wind-induced vibration performance of long-span suspension bridges is the wind resistance stability, that is, the flutter stability of suspension bridges. Improving the wind resistance stability performance is an important issue in the design of long-span suspension bridges. The flutter stability of structures under wind has become an important factor affecting the construction of long-span suspension bridges.

Improving the wind resistance stability of long-span suspension bridges should mainly focus on improving the overall stiffness of the suspension bridge structural system, supplemented by means of controlling the structural vibration characteristics of the suspension bridge and improving the aerodynamic performance of the section. The structural stiffness of long-span suspension bridges mainly comes from the main cables, and the focus of improving the overall stiffness of the suspension bridge structure should be to increase the spatial stiffness of the main cables. Therefore, in the field of bridge engineering, in order to build a 3000-5000-meter super-long-span suspension bridge across the sea and islands, there is an urgent need for a super-long-span suspension bridge structure with a new type of space cable system with strong wind resistance and stability.

Single-leaf hyperboloid and hyperbolic paraboloid are typical quadratic ruled surfaces, which can be composed of two families of straight lines. Quadratic ruled surfaces have important application value in architecture, and are often used to form the skeleton of buildings. Buildings constructed with straight-grain curved surfaces have excellent mechanical properties, simple construction technology, and it is more convenient to stretch linear prestressed steel wires. The buildings have beautiful appearance and firm structure. The roof shape of many large warehouses, concert halls, and gymnasium buildings is in the shape of a hyperbolic parabolic saddle, and the prestressed steel wires are stretched in a straight line to meet the bearing capacity requirements of large-span roof structures. Utilizing the straight grain of the single-leaf hyperboloid, firmly connecting the intersection points of the two families of straight lines together, you will get a very light and very strong building. The commonly used shape of the huge cooling tower of the power plant is the single-leaf hyperboloid. Rattan flower baskets also often use a single-leaf hyperboloid shape. The 600-meter-high Guangzhou TV Tower "Xiaomanyao" is built using the ruled principle of a single-leaf hyperboloid.

Drawing on the structure of Medog Teng Bridge in Tibet, China, and according to the design concept of "tensioned whole" long-span structure, using the straight grain characteristics of the single-leaf hyperboloid to construct a space cable network, forming a space cable system in the form of a single-leaf hyperboloid, Fix the intersecting nodes of the main cables of the space cable net, set up an elliptical steel structure to strengthen the ring beam, improve the space rigidity of the cable system, and adopt a portal-type steel structure rigid central buckle to strengthen the coupling effect of the space cable and the stiffening beam, and finally install The suspender and the stiffened beam bridge deck are used to construct a suspension bridge with a single leaf hyperboloid space cable network and a main cable with a large span.

Utility model content

Technical problem: The utility model provides a super-large-span suspension bridge with a single-leaf hyperboloid space cable net main cable with large structural space rigidity, strong spanning ability, and good wind resistance stability. According to the straight grain characteristics of the single-leaf hyperboloid, the vertical parallel cable system of the traditional suspension bridge is reformed, and the thick and heavy concentrated cables are replaced by scattered space steel wire cables. Channel Channel Suspension Bridge.

Technical solution: The super-long-span suspension bridge of the single-leaf hyperboloid space cable net main cable of the utility model includes a tubular net space main cable, a bridge tower, a steel ring tower head, a suspender, a stiffened steel beam and an anchorage, and a tubular net As the main cable of the suspension bridge, the steel-shaped space main cable is connected to the steel ring tower head. The steel ring tower head is set on the top of the bridge tower. It is composed of several steel wire cables intersecting in space, and its spatial configuration is a closed tubular cable net formed by the drooping of the single-leaf hyperboloid space cable net. Holes are left, and the two ends of the main cable in the tubular mesh space are anchored in the anchorage. Along the longitudinal direction of the suspension bridge, multiple elliptical steel ring beams are arranged in the main cable of the tubular mesh space. The steel wire cables of the main cable of the tubular mesh space pass through the oval steel ring beams and are fixedly connected with them. On the steel ring beam, the lower end of the suspender is connected with the stiffened steel beam. There are several portal-type rigid central buckles in the middle area of the suspension bridge. The lower end of the portal-type rigid central buckle is connected to the stiffened steel beam, and the upper end is connected to the elliptical steel ring beam.

The construction method of the extra-large span suspension bridge of the single leaf hyperboloid space cable net main cable of the present utility model comprises the following steps:

Step 1: Excavate the foundation pit, construct the bridge foundation, construct the bridge tower, steel ring tower head and anchorage of the suspension bridge;

Step 2: After erecting the traction cables and constructing temporary construction catwalks, carry out precise measurement and lofting according to the equation of the single-leaf hyperboloid. Circle the reserved hole of the tower head, use the anchorage to anchor the main cable of the cylindrical mesh space in the anchorage, erect the main cable of the cylindrical mesh space, and use U-shaped clamps to fix the cable after tightening the cable and adjusting the line shape of the space cable The crossing point of the main cable in the cylinder network space;

Step 3: Transport the elliptical steel ring beam with the inner and outer layer structure in place, install the elliptical steel ring beam, and use clamps to firmly connect the main cable of the tube mesh space with the elliptical steel ring beam. Internal steel support is set to form a transverse rigid section and strengthen the spatial rigidity of the main cable in the cylindrical mesh space;

Step 4: Firmly install the upper end of the boom on the lug of the oval steel ring beam, hoist the stiffened steel beam in place, and fix the stiffened steel beam to the lower end of the boom;

Step 5: In the middle area of the suspension bridge, install the portal-type rigid central buckle, connect the lower end of the portal-type rigid central buckle to the stiffened steel beam, and connect the upper end to the oval steel ring beam, and strengthen the main cable and stiffened steel beam in the mesh-like space of the tube To improve the wind resistance stability, railings and bridge deck pavement are finally installed to form a super-long-span suspension bridge with a single-leaf hyperboloid space cable system, and a super-long-span strait suspension bridge with a length of 3,000 to 5,000 meters will be built.

With the continuous increase of the span of the suspension bridge, the bending frequency and the torsional frequency of the long-span suspension bridge of the parallel cable system are close to each other, and the critical wind speed of flutter of the long-span suspension bridge structure decreases. The flutter critical wind speed of long-span suspension bridges is related to the ratio of torsional frequency and torsion-bending frequency of the suspension bridge. The use of space cable system suspension bridges is the most effective method to improve the flutter stability of long-span suspension bridges. The overall structural stiffness of long-span suspension bridges mainly comes from the stiffness of the cable system. Changing the parallel cable system suspension bridge into a single-leaf hyperboloid space cable system suspension bridge can greatly improve the lateral force stiffness and torsional stiffness of the long-span suspension bridge, which can increase The torsional frequency and torsional frequency ratio of the long-span suspension bridge structure improve the flutter stability of the long-span suspension bridge. The rigid central buckle of the portal steel structure is used to connect the space cable and the stiffening beam, which can couple the torsional vibration of the stiffening beam and the torsional vibration of the space cable system to a certain extent, and can couple the torsional vibration of the space cable and the stiffening beam Coupled with the lateral horizontal vibration to a certain extent, the purpose of improving the torsional stiffness and torsional frequency of the long-span suspension bridge structure is achieved, and the wind resistance stability of the long-span suspension bridge is enhanced.

Single-leaf hyperboloid is a typical ruled surface, which can be composed of two families of straight lines. Ruled surface has important application value in architecture, and it is often used to form the skeleton of buildings. There are many intersection nodes in the single-leaf hyperboloid ruled grid system, and connecting and fixing these intersection points can improve the integrity of the single-leaf hyperboloid spatial cable structure system. Using single-leaf hyperboloid space cable network main cables as load-bearing cables of long-span suspension bridges can improve the spatial structure stiffness of long-span suspension bridges, increase the lateral force stiffness, torsional stiffness and torsional frequency of suspension bridge structures, and improve the performance of long-span suspension bridges. Flutter stability.

In order to strengthen the spatial rigidity and integrity of the space cable system, in the single leaf hyperboloid space cable system, an elliptical steel structure reinforced ring beam is configured, and the elliptical steel structure reinforced ring beam adopts an inner and outer assembled steel structure ring beam Forming, the inner and outer steel ring beams are clamped by clamps, the outer ring beam hangs the upper cable net, and the inner ring beam hangs the lower net cable net. The elliptical steel structure strengthens the ring beam structure with lifting lugs, which can facilitate the installation of three-dimensional suspenders and ensure that the stiffened beam deck system and the space cable system work together under force.

The space cable system of the large-span single-leaf hyperboloid space cable system is very beautiful in appearance, and its appearance is like a small waist. The transverse section of the single-leaf hyperboloid is a group of ellipses. The ellipse at the middle waist is the smallest, and the ellipse sections at both ends gradually become larger. The equation of the lateral section of the single-leaf hyperboloid is a hyperbola, and the side of the single-leaf hyperboloid space cable system is a symmetrical concave curved surface cable network, which is like a wind cable, tightly pulling each other to hold the elliptical steel structure The ring beam is strengthened, and the single-leaf hyperboloid space cable system can provide the horizontal component force of the cable, resist the huge wind load of the strait environment, ensure the lateral stability of the long-span suspension bridge structure, and improve the wind resistance of the long-span suspension bridge.

In order to improve the wind-resistant stability of long-span suspension bridges, several steel structure portal-type rigid buckles are installed in the mid-span area of long-span suspension bridges to connect structural components such as space cables, elliptical steel structure ring beams, and steel stiffening beams. Being integrated can increase the structural integrity of the long-span suspension bridge, and can couple the torsional vibration of the stiffening beam and the torsional vibration of the space cable system to a certain extent, further improving the space torsional stiffness of the suspension bridge structure.

The utility model is based on the design concept of "tensioned whole" long-span structure, the straight grain characteristic of the single-leaf hyperboloid, and the wind-resistant stability force requirements of the super-long-span Strait suspension bridge, and reforms the vertically parallel cable system of the traditional suspension bridge. , the thick and heavy concentrated cables are replaced by scattered space steel cables, and the multi-strand steel cables are arranged in a cross space to form a space cable mesh suspension structure system in the form of a single-leaf hyperboloid. The space cable intersection nodes are fixed and an elliptical steel structure is set. Strengthen the ring beam, install the rigid central buckle of the portal steel frame to connect the space cable and the stiffening beam, increase the structural integrity of the long-span suspension bridge, improve the torsional stiffness and lateral stiffness of the space cable system suspension bridge, and install the suspender and stiffening beam For the bridge deck system, build a super-long-span suspension bridge with a single-leaf hyperboloid space cable network main cable, fundamentally solve the problem of wind-resistant stability of long-span suspension bridges, and meet the technical requirements for building 3,000-5,000-meter super-long-span suspension bridges across the Strait Require.

Beneficial effect: compared with the prior art, the utility model has the following advantages:

With the development of the construction boom of cross-sea and island-connecting projects, the span of the strait suspension bridge is increasing continuously, and the structure of the suspension bridge is becoming softer and softer. The stability of the structure against wind has become an important factor affecting the construction of long-span suspension bridges.

The utility model is based on the design concept of "tensioned whole" large-span structure, and utilizes the straight grain characteristics of the single-leaf hyperboloid to reform the vertical parallel cable system of the traditional suspension bridge. Concentrated cables are changed to scattered space steel cables, multi-strand steel cables are arranged in space, and space cable cross nodes are fixed to form a space cable network suspension cable structure system in the form of a single-leaf hyperboloid, and a single-leaf hyperboloid space cable system is constructed Extra long-span suspension bridge with network main cable.

Compared with the traditional vertical parallel cable system suspension bridge, the single-leaf hyperboloid space cable network suspension structure system increases the spatial stiffness of the long-span suspension bridge, and improves the torsional stiffness and lateral stiffness of the long-span suspension bridge. The torsional frequency of the suspension bridge is increased, the torsional-bending frequency ratio of the suspension bridge is increased, and the critical wind speed of flutter of the long-span suspension bridge is greatly improved, which can fundamentally solve the problem of the wind-resistant flutter stability of the long-span suspension bridge.

In the single-leaf hyperboloid space cable system, an elliptical steel structure strengthening ring beam is set every 30 to 40 meters to strengthen the spatial rigidity and integrity of the single-leaf hyperboloid space cable system suspension bridge and ensure the space cable system The strands of steel wire cable work together. The elliptical steel structure reinforced ring beam adopts the form of inner and outer steel ring beam rings. The inner and outer steel ring beams are clamped with clamps. The outer ring beam hangs the upper layer of cable net, and the inner ring beam hangs the lower layer of cable net. Setting the elliptical steel structure to strengthen the ring beam can strengthen the torsional stiffness of the space cable system suspension bridge, increase the flutter critical wind speed of the long-span suspension bridge, and improve the wind resistance stability of the space cable system suspension bridge.

The installation of flat elliptical steel ring beams is beneficial to the installation and construction of the suspenders. At the mid-span of the suspension bridge, the section width of the flat elliptical steel ring beams is 3/4 to 4/5 of the width of the deck system, and inwardly inclined suspension beams can be installed. The rod pulls the stiffening beam, which is conducive to improving the flutter stability of the long-span suspension bridge; at the position of the bridge tower, the section width of the flat elliptical steel ring beam is 2 to 3 times the width of the bridge deck, and the outwardly inclined suspenders can be installed Pulling the stiffening beam is beneficial to improve the anti-static wind performance of the long-span suspension bridge.

The main cable system of the single-leaf hyperboloid space cable network suspension bridge looks like a small waist. The side of the space cable system is a symmetrical concave surface cable network. The elliptical steel structure is pulled against each other to strengthen the ring beam. The single-leaf hyperboloid space cable system has a relatively large stiffness against lateral force, and the space cable network main cable can provide the horizontal force component of the cable. Therefore, the long-span suspension bridge has It has a great anti-lateral static wind load capacity, can resist the huge wind load in the Strait area, and can ensure the lateral stability of the long-span suspension bridge structure.

In the middle area of the long-span suspension bridge, several portal-type steel structure rigid central buckles are installed to strengthen the coupling effect of the space cable and the stiffening beam, enhance the cooperative work ability of the space cable and the stiffening beam, and increase the structural integrity of the long-span suspension bridge . The portal-type rigid central buckle can couple the torsional vibration of the stiffening beam and the torsional vibration of the space cable system to a certain extent, and couple the torsional vibration of the space cable and the stiffening beam with the lateral horizontal vibration to a certain extent. Torsional stiffness, torsional frequency and torsional bending frequency ratio of long-span suspension bridge structure, increase the damping of long-span suspension bridge structure, change the vibration characteristics of long-span suspension bridge structure, increase the critical wind speed of flutter, and improve the wind resistance stability of long-span suspension bridge .

The single-leaf hyperboloid space cable system suspension bridge of the utility model has the advantages of strong spanning ability, large structural space rigidity, and good wind resistance stability, etc., and can fundamentally solve the problem of the wind flutter resistance stability of the super-long-span suspension bridge, so as to build 3000 ~5,000-meter super-long-span Strait Suspension Bridge.

Description of drawings

Fig. 1 is the three-dimensional schematic diagram of the whole bridge of the extra large span suspension bridge of the utility model single leaf hyperboloid space cable net main cable;

Fig. 2 is the three-dimensional schematic diagram of the pylon of the extra-large span suspension bridge of the utility model single leaf hyperboloid space cable net main cable;

Fig. 3 is the schematic diagram of the anchorage foundation of the extra-large span suspension bridge of the utility model single leaf hyperboloid space cable net main cable;

Fig. 4 is a mid-span cross-sectional schematic diagram of a super-large-span suspension bridge with a single-leaf hyperboloid space cable net main cable of the utility model;

Fig. 5 is a 1/4 point cross-sectional schematic diagram of a super-large-span suspension bridge with a single-leaf hyperboloid space cable net main cable of the utility model;

Figure 6 is a schematic diagram of the configuration of a single-leaf hyperboloid space cable network.

In the figure, there are: main cable 1 in tube mesh space; bridge tower 2; steel ring tower head 3; oval steel ring beam 4; suspender rod 5;

Detailed ways

Below in conjunction with accompanying drawing of description, the utility model is described in further detail.

Example 1:

The extra-large-span suspension bridge of the single-leaf hyperboloid space cable net main cable of the utility model includes a tube mesh space main cable 1, a bridge tower 2, a steel ring tower head 3, an oval steel ring beam 4, a suspender 5, and a stiffener The steel beam 6, the portal rigid central buckle 7 and the anchorage 8, the main cable 1 is composed of several steel wire cables intersecting in space, and its spatial configuration is a closed tube formed by the sagging of the single-leaf hyperboloid space cable net. The cable net, the main cable 1 in the cylindrical mesh space is used as the main cable of the super-long-span suspension bridge, the steel ring tower head 3 fixes the top of the bridge tower 2, and the steel wire cable of the main cable 1 in the cylindrical mesh space passes through the steel ring tower head 3. Holes are reserved and anchored in the anchorage 8. The main cable 1 in the tubular mesh space is arranged longitudinally along the suspension bridge with multiple elliptical steel ring beams 4, and the upper end of the suspender 5 is fixed on the elliptical steel ring beam 4. The beam 6 is suspended below the main cable 1 in the cylindrical net-like space through the suspender 5 and the oval steel ring beam 4. Several portal-type rigid central buckles 7 are arranged in the middle area of the suspension bridge, and the lower ends of the portal-type rigid central buckles 7 are fixed to the stiffened steel The upper end of the beam 6 is connected with the elliptical steel ring beam 4 to strengthen the structural integrity of the main cable 1 and the stiffened steel beam 6 in the tubular mesh space.

Example 2:

The construction method of the extra-large span suspension bridge of the single leaf hyperboloid space cable net main cable of the present utility model comprises the following steps:

Step 1: According to the geological topography, landform conditions and navigation requirements, select the bridge site for the super-long-span Strait Suspension Bridge, excavate the foundation pit, construct the bridge foundation, and build the bridge tower 2 and steel ring tower head 3 of the super-long-span Strait Suspension Bridge and anchor 8;

Step 2: After erecting the traction cables and constructing temporary construction catwalks, carry out accurate measurement and lofting according to the equation of the single-leaf hyperboloid, arrange the multi-strand cables crosswise in space, and pass the traction wire cables through the steel ring tower head 3 reserved holes , anchored in the foundation of the anchorage 8, erect the main cable 1 in the cylindrical reticulated space, carry out the work of tightening the cable and adjusting the alignment of the space cable, and then fix the crossing point of the main cable 1 in the cylindrical reticulated space;

Step 3: transport the elliptical steel ring beam 4 in the form of inner and outer layers into place, install the elliptical steel ring beam 4, and firmly connect the main cable 1 and the The inside of the ring beam 4 is provided with steel supports to form multiple transverse rigid sections to strengthen the space rigidity of the main cable 1 in the cylindrical mesh space;

The fourth step: firmly install the upper end of the suspender 5 on the lug of the oval steel ring beam 4, hoist the stiffened steel beam 6 in place, and fix the stiffened steel beam 6 to the lower end of the suspender 5;

Step 5: In the middle area of the long-span suspension bridge, install the portal-type rigid central buckle 7 to strengthen the cooperating ability of the main cable 1 and the stiffened steel girder 6 in the cylindrical mesh space, improve the wind resistance stability, and finally install the railing and the bridge deck Paving, forming a super-long-span suspension bridge with a single-leaf hyperboloid space cable system, and building a 3,000-5,000-meter super-long-span suspension bridge across the Strait.

Example 3:

A certain Strait Bridge is a super long-span suspension bridge for highway and railway, with a main span of 3600m and a bridge deck width of 60m. The sub-span of the suspension bridge is 1200m+3600m+1200m. The middle part of the bridge deck is a double-track railway. In order to meet the requirements of wind resistance and stability, a super-long-span suspension bridge with a single-leaf hyperboloid space cable network main cable is adopted. The bridge tower is a gate-post type bridge tower with a height of 420 meters. The bridge tower is a steel-concrete composite structure. Shaped underground continuous wall structure. The anchorage adopts a large-volume reinforced concrete structure, and the prismatic anchorage can make the anchorage embedded in the soil. An elliptical steel ring tower head is set on the top of the bridge tower structure. The major axis size of the steel ring tower head is 120 meters, and the short axis size is 60 meters. The main cable of the suspension bridge adopts a single-leaf hyperboloid space cable system, and the space of the steel wire cables is arranged crosswise. The main cable is composed of 32 cables. The prefabricated parallel strand method (PPWS method) technology is adopted, and the φ5.2mm high-strength steel wire of 1800MPa is used. Each cable is 45.8 cm in diameter. The elliptical steel ring girder is composed of a series of elliptical steel ring beams of different sizes. The ellipse at the middle waist of the bridge is the smallest, and the elliptical cross-sections at both ends gradually become larger. The long axis dimension of the elliptical steel ring beam at the middle waist of the bridge is is 40 meters, and the minor axis dimension is 20 meters. The bridge deck is equipped with two sets of prestressed steel wire suspenders on the left and right, the distance between the suspenders is 30 meters, and there are 2×120 suspenders in total. The stiffening beam adopts the steel truss type stiffening beam, and the height of the steel truss is 12 meters. Five rigid central buckles are set in the middle area of the suspension bridge, and steel structure portal rigid buckles are adopted to further strengthen the integrity of the main cable and the stiffened steel girder in the cylindrical mesh space.

The construction process of the extra-large-span suspension bridge of the single-leaf hyperboloid space cable network main cable of the utility model is as follows: site selection of the long-span suspension bridge--bridge tower construction--anchor construction--space cable system construction--installation of elliptical Steel structure reinforced ring beam - installation of suspenders - hoisting of stiffening beams - installation of rigid central buckles - bridge deck pavement, etc. During the construction of a super-long-span suspension bridge with a single-leaf hyperboloid space cable system, attention must be paid to each link. The specific construction techniques are as follows:

(1) Site selection for long-span suspension bridges

Suspension bridges are long-span bridges, and multi-scheme comparative analysis should be carried out, as well as technical and economical analysis and research. The site selection of long-span suspension bridges should comprehensively consider the requirements of hydrology, topography, ground features, geomorphology, and engineering geology, and the long-term planning requirements for navigable rivers should be considered. The position of the bridge should be set as far as possible on the river section where the river course is straight, the mainstream is stable, and the river channel can pass through relatively concentrated flow. The bridge position of the suspension bridge should be selected in the narrower part of the river course. Suspension bridges are long-span bridges, and the positions of bridge towers and anchorages require good geological conditions. Suspension bridges should be located in areas with single geological structures, stable rocks, shallow bedrock burial, solid soil layers, and good geology. Suspension bridges should not be located in unfavorable areas such as faults, landslides, karst caves, saline soils, and swamps, and should avoid fault fracture zones, especially recent active earthquake fault zones.

The long-span strait suspension bridge should make full use of the islands in the sea, and the bridge can be built in sections. Suspension bridges across the strait should adopt long-span suspension bridges as far as possible to meet the development requirements of waterways, and at the same time try to avoid building piers in deep water. The cross-strait suspension bridge with a single-leaf hyperboloid space cable system should choose a solid bedrock site on both sides of the bridge, so that tunnel-type composite anchors can be used, and prestressed rock anchors can be used to exert the anchoring force of deep rocks, reduce engineering costs, and ensure cable anchorage Safe and reliable.

(2) Bridge tower construction

The height of the pylons of long-span suspension bridges is usually more than 100 meters, which belongs to the category of high-rise structures. The pylons are important stress-bearing components of long-span suspension bridges, bearing vertical loads such as the weight of the main cable, the weight of the bridge deck, and vehicle loads. , The tower column must have a strong compressive bearing capacity, and the tower column foundation must be firm and reliable. At the same time, the tall suspension bridge tower bears huge wind load and earthquake force, therefore, the suspension bridge tower should be guaranteed to have a strong lateral bearing capacity.

The common horizontal structure forms of suspension bridge towers are rigid structure, truss type and mixed type. The rigid structure type has a bright and simple appearance and is convenient for construction. It has a large resistance to horizontal loads, but the construction of cross-braced diagonal bars is difficult, and the truss-type bridge tower is suitable for suspension bridges with a span of more than 2000 meters. The common longitudinal structure forms of suspension bridge towers are I-shaped, A-shaped and herringbone-shaped. I-shaped bridge towers are simple in form and easy to construct. Herringbone-shaped bridge towers have high longitudinal stiffness, but their construction is difficult, and they are suitable for the middle towers of multi-span multi-tower suspension bridges or single-span suspension bridge towers with a span of more than 3000 meters.

Suspension bridge tower building materials are classified into concrete structure, steel structure and composite structure. The concrete tower column structure has the advantages of large compressive bearing capacity, convenient construction, low cost and low maintenance cost, but the construction period is long. In recent years, the construction method of slipform concrete has been adopted, and the construction of high concrete tower columns has become very convenient. The steel structure tower column structure has the characteristics of fast construction speed, factory prefabrication and simple cross-bracing construction, but the cost is relatively high.

Suspension bridges with a single-leaf hyperboloid space cable system are suitable for super-long-span channel suspension bridges of 3,000 to 5,000 meters. The tower height above the bridge deck is calculated according to 1/9 to 1/11 of the span, which should be 280 to 500 meters. The navigable height below the surface is 80-90 meters, and the total height of the bridge tower is about 360-580 meters. Therefore, the pylon of the Strait Suspension Bridge with the single-leaf hyperboloid space cable system has a huge amount of work and a huge force on the pylon structure. The proposed horizontal structure form adopts the truss type pylon, and the longitudinal structure form adopts the A-shaped or herringbone pylon. The middle and lower part of the tower body is constructed of concrete-steel composite structure, and the upper bridge tower is constructed of steel structure.

The ultra-long-span Strait Suspension Bridge adopts a single-leaf hyperboloid space cable network cable system, which can enhance the wind resistance stability of the long-span suspension bridge. The cross section of the single-leaf hyperboloid space cable system presents an elliptical cross-section. The giant flat elliptical steel ring beam supports the single leaf hyperboloid space cable system. Since the elliptical section width of the single-leaf hyperboloid space cable system at the pylon position is greater than the width of the bridge deck system, a giant cantilevered cantilever can be installed on the top of the pylon of the long-span Strait Suspension Bridge of the single-leaf hyperboloid space cable system. The structure of flat elliptical steel ring girder, the shape of the top of the bridge tower is like a transmission tower with cantilever form, and the giant flat elliptical steel ring girder is firmly welded with the bridge tower column. A steel support structure is set in the giant flat oval steel ring girder to ensure the stress safety of the flat oval steel ring girder structure, and a pre-buried steering hollow steel pipe is set to replace the traditional saddle so that the cables can be turned at the bridge tower. The pylons of long-span suspension bridges with single-leaf hyperboloid space cable systems should adopt four-column A-shaped pylons, and the four columns are connected by giant beams and diagonal supports.

(3) Anchorage construction

Anchorage is an important component of suspension bridge, which plays the role of anchoring the main cable, and it transmits the tension in the main cable to the foundation. The common forms of anchorage for suspension bridges are gravity anchorage and tunnel anchorage. The gravity anchor relies on its own weight to resist the vertical component of the main cable, while the horizontal component of the cable is resisted by the frictional resistance or embedded force between the anchor and the foundation. Early suspension bridge gravity anchors mostly used steel frame anchorage systems. The entire steel frame was poured in the anchor block concrete, and the main cable strands corresponded to the section steel tie rods. This system used a large amount of steel and complicated construction. The steel frame anchorage system has been gradually replaced by the prestressed anchorage system. The prestressed anchorage system is composed of prestressed tendons and cable strand connectors. The main cable strands are connected to the prestressed tendons through the connectors to transfer the force to the anchor block. The system uses The amount of steel is small, the layout is flexible, and the construction is convenient.

When there is solid bedrock on both sides of the suspension bridge, tunnel-type anchorage can be used. Diagonal tunnels are excavated in the bedrock, anchor plates are installed at the bottom of the tunnel, and a section of wedge-shaped concrete cone is filled as anchor blocks, which can greatly save the number of projects. Reduce project cost.

The single-leaf hyperboloid space cable system suspension bridge is generally used for super-long-span strait suspension bridges. The tension of the cables is huge, and a huge anchorage force is required. The anchorage system needs to be scientifically improved. It is recommended to adopt the tunnel composite anchorage system, make full use of the surrounding rock at the back end of the anchorage, and use the prestressed rock anchor to mobilize the anchoring force of the deep rock. The prestressed rock anchor and the tunnel-type conical anchor block structure work together. Compared with the traditional gravity anchor and tunnel anchor, the anchor structure gives full play to the axial stiffness of the prestressed rock anchor, and the prestressed rock anchor anchors deep rocks, greatly increasing the anchoring force, which can ensure that the new single leaf hyperboloid Anchorage requirements for space cable system suspension bridge cables.

(4) Space cable system construction

The main cable is the lifeline of the suspension bridge. The main cable is a flexible load-bearing member suspended on the main tower through the saddle on the top of the tower and anchored in the anchorages at both ends. It is connected with the stiffened beam through the cable clamp and suspender. , vehicle live load, temperature load and lateral wind load, and transmit the load to the top of the tower.

The main construction procedures for the erection of the main cable of the suspension bridge are: erection of guide cables and traction cables - erection of catwalks - erection of main cables - installation of cable clamps and booms.

The guide cables of suspension bridges are usually erected by seabed pulling method, buoy frame method, free suspension method and helicopter hoisting. Then, the guide cable is used to erect the traction cable and the catwalk load-bearing cable by using a reciprocating pulling system.

The catwalk structural system of the suspension bridge is composed of catwalk load-bearing cables, catwalk surface, railings, horizontal bridges and catwalk wind cables. The catwalk of the suspension bridge is an important aerial walkway and working platform, which is used for dragging and erecting, measuring, adjusting, tightening the main cable, installing cable clips and slings, winding the main cable and protecting the main cable. During the construction of the suspension bridge, two catwalks are generally provided. Each catwalk is required for the construction of the main cable on one side, and the width of the catwalk is generally about 4 meters. In order to enhance the overall rigidity of the catwalk and meet the needs of traffic, a catwalk horizontal bridge is installed at an appropriate position to connect the catwalks on both sides. In order to improve the wind-resistant stability of the catwalk and adjust the shape of the catwalk surface, the catwalk wind-resistant cables are set up, and the catwalk wind-resistant cables and the catwalk load-bearing cables are connected by stay cables.

The method of erecting the main cable of the suspension bridge includes the aerial spinning method (AS method) and the prefabricated parallel strand method (PPWS method). The prefabricated parallel cable strand method is an installation method that transports the cable strands composed of parallel high-strength steel wires prefabricated in the factory to the construction site. Each bundle of prefabricated cable strands contains 61, 91, and 127 steel wires with a diameter of 5.2mm, and hot-cast anchor heads are embedded at both ends. , whose shape is a regular hexagon. The strands are pulled up the tower one by one by the tow rope, put into the saddle and connected with the anchor rod.

The traction method of the main cable strand is divided into two types: the traction method of the gantry type puller and the traction method of the rail trolley. The prefabricated main cable strand is connected with the puller installed on the traction cable, and the traction cable drives the puller through the catwalk door frame guide wheel group, the tower top door frame guide wheel group, and the anchorage door frame guide wheel through the driving device. The group makes a reciprocating movement, and the steel wire strands are pulled and laid on the catwalk along the catwalk roller one by one. During the cable strand traction and erection process, it should be pulled at a uniform speed as much as possible.

The main process of erecting the main cable strands is as follows: ① wire strand traction erection: use pulling facilities to pull and erect the prefabricated wire strands through the catwalk, and the anchor head is temporarily anchored; The cable strands are lifted from the rollers and moved horizontally to the top of the saddle, and then put into the saddle after shaping; ③Adjustment of the sag of the strands: Adjust the sag of the strands at night when the temperature is stable, that is, the absolute elevation of the mid-span of the reference strands Control and adjust the mid-span relative elevation of the non-reference wire strands, ④ adjust the tension of the strands, and the anchor head is formally anchored.

After all the strands of the main cable are erected and in place, the next work is to tighten the cable, the purpose of which is to compress the main cable into a circular shape to meet the design requirements for void ratio and to meet the requirements for installing cable clamps. The cable tightening construction process has two stages: initial cable tightening and formal cable tightening. Pre-tighten the cable at night when the temperature is stable, use jacks and other tools to make a preliminary round of the main cable, and use temporary steel straps for every 5m. After the pre-tightening operation is completed, use the cable tensioning machine to carry out the formal cable tensioning operation from the low place to the high place (from the mid-span to the top of the tower). After the main cable is tightened, the installation of cable clips and slings, the installation of stiffening beams, the winding of the main cable and the anticorrosion of the main cable can be carried out.

The single-leaf hyperboloid space cable system suspension bridge adopts a space cable system, and its cable construction requires higher precision. On the basis of the traditional suspension bridge cable erection technology, appropriate reforms can be carried out to realize the construction of the single-leaf hyperboloid space cable system. First, at the center height of the single-leaf hyperboloid space cable at the bridge tower, a catwalk is set along the longitudinal axis of the long-span bridge as a temporary construction transportation platform. Pull the wire ropes to the catwalk one by one, use lifting equipment to lift the wire ropes to the position of the giant flat elliptical steel ring beam of the bridge tower, and use anchors to anchor the wire ropes on the bridge tower to form a group of parallel steel wire ropes in the shape of an ellipse cylinder. Then, the position of the steel wire rope is moved in an oblique direction and the anchorage is anchored on the bridge tower to form a single-leaf hyperboloid space steel wire rope net, which connects the intersection points of the steel wire space space net to form a single-leaf hyperboloid space cable net temporary construction transportation catwalk. When constructing the transport catwalk, a number of eight-shaped temporary cables can be arranged behind the bridge tower to balance the force on the bridge tower structure. The temporary construction transportation catwalk using the single-leaf hyperboloid space steel wire rope net pulls the main cable strands and passes through the hollow steering steel pipe from the bridge tower. , after all the steel wire strands are erected in place, each main cable strand is tightened into a circular cross-section, and U-shaped clamps are used to connect and fix the intersection points of the main cable space network to form a single-leaf hyperboloid space cable system, and an elliptical steel structure is installed to reinforce it. The ring beam is installed with cable clips, suspenders, and hoisted with stiffening beams to form a super-long-span suspension bridge with a single-leaf hyperboloid space cable network main cable.

The space cable system with ruled surface of the single-leaf hyperboloid has a very beautiful appearance. The ellipse at the waist position is the smallest, and the elliptical section at both ends gradually becomes larger. The variable-section cable arrangement of the single-leaf hyperboloid space cable system is very beneficial to the wind resistance stability of the long-span suspension bridge structure. The equation of the lateral section of the single-leaf hyperboloid is a hyperbola, and the side of the single-leaf hyperboloid space cable system is a symmetrical concave curved surface cable network, which is like a wind cable, tightly pulling each other to hold the elliptical steel structure The ring beam is strengthened, and the single-leaf hyperboloid space cable system can provide the horizontal component force of the cable, resist the huge wind load of the strait environment, ensure the lateral stability of the long-span suspension bridge structure, and improve the wind resistance of the long-span suspension bridge.

(5) Install the elliptical steel structure to strengthen the ring beam

In order to strengthen the spatial rigidity and integrity of the suspension bridge of the single-leaf hyperboloid space cable system, and to ensure that the steel wire cables of the space cable system work together, in the single-leaf hyperboloid space cable system, a bridge should be installed every 30 to 40 meters. The elliptical steel structure strengthens the ring beam. The cross-sectional size of the steel ring beam ring should be adapted to the section of the single leaf hyperboloid space cable system. One end of the suspender is fixed on the steel structure reinforced ring beam to hang the stiffening beam. The elliptical steel structure strengthened ring beam should adopt the form of inner and outer steel ring beam rings, the inner and outer steel ring beams are clamped with clamps, the outer ring beam hangs the upper layer of cable nets, and the inner ring beams hangs the lower layer of cable nets. The setting direction of the structural strengthening ring beam should be perpendicular to the cable section of the space net to ensure the transmission of the force of the boom to the space cable net. Inside the elliptical steel structure reinforced ring beam, steel structure support rods are arranged to strengthen the rigidity of the elliptical steel ring beam and reduce the stress of the steel ring beam.

At the mid-span of the suspension bridge, the section width of the flat elliptical steel ring beam should be 3/4 to 4/5 of the width of the deck system, and at the position of the bridge tower, the section width of the flat elliptical steel ring beam should be 2 to 3 times The width of the bridge deck and the aspect ratio of each elliptical section should be about 1/2. The lowest point of the single-leaf hyperboloid space cable system network at the mid-span position should be greater than 15 meters away from the stiffening beam deck system, so as to meet the traffic clearance requirements on the bridge. In the middle area of the suspension bridge, setting inwardly inclined suspenders to hold the stiffening beam is beneficial to improve the flutter stability of long-span suspension bridges; near the bridge tower, setting outwardly sloping suspenders to hold the stiffening girder is conducive to improving the stability of large span suspension bridges. Static wind performance of span suspension bridges. The installation of the flat elliptical steel ring beam is beneficial to the installation of the suspender, which can strengthen the integrity of the space cable system suspension bridge, improve the spatial stiffness of the single leaf hyperboloid space cable system suspension bridge, and improve the wind resistance stability of the space cable system suspension bridge.

(6) Install the boom

The suspender of the suspension bridge is a component that transmits the dead load of the stiffened beam and the live load acting on the stiffened beam to the main cable. Its upper end is connected with the cable clamp, and its lower end is connected with the stiffened beam. The suspenders can be divided into traditional vertical suspenders and oblique suspenders according to their facade layout. The oblique suspenders have a truss effect, which increases the overall longitudinal stiffness of the suspension bridge, reduces deflection, and increases the natural frequency of bending vibration. Reduce the vibration and bump of the bridge up and down, and improve the driving comfort. The inclined suspender has a relaxation effect, which increases the damping of the structure, which is beneficial to the wind and earthquake resistance of the suspension bridge. However, due to the truss effect of the inclined suspender, the stress of the suspender caused by the live load varies greatly, and the repeated stress will cause the fatigue of the node material, which will cause the suspender to be damaged at the root anchor cup, and the rainwater intrusion will cause corrosion of the suspender wire rope.

The single-leaf hyperboloid space cable system suspension bridge is a kind of suspension bridge used for the long-span Strait Bridge. Due to its own characteristics, it is suitable to adopt the three-dimensional space oblique suspender arrangement. Strengthen its spatial rigidity, increase the torsional natural vibration frequency of the suspension bridge, and improve the wind resistance stability. The bridge deck of the long-span suspension bridge with single-leaf hyperboloid space cable system is relatively wide, so it is advisable to arrange a suspender in the middle of the bridge deck and set a middle isolation belt.

(7) Hoisting stiffening beams

The stiffening girder types of long-span suspension bridges mainly include flat closed steel box girder type and steel truss type. The flat closed box girder type is often used in suspension bridges in European countries, and the truss type is commonly used in suspension bridges in the United States, Japan and other countries. The truss-type stiffened beam has good ventilation performance and high structural rigidity, and the stiffened beam can achieve relatively high torsional stiffness, so its flutter critical wind speed is relatively high. The advantages of box girder stiffening girders are cost savings and better aesthetic effects. The wind resistance of box girder stiffening girders is limited by many factors. The flutter stability of box girder type suspension bridges is not as good as that of truss type stiffening girder suspension bridges. Pay attention to the aerodynamic shape of the stiffened beam section and the ratio of its width to span, etc.

Steel box-type stiffened girder suspension bridges have good adaptability when the span is 1000-2000m, and the wind resistance stability should be considered carefully when the span is larger. The truss type stiffened girder suspension bridge has the widest application range, and has good adaptability with a span of 1500-5000m.

To improve the flutter performance of a suspension bridge with closed box girder stiffened girders, it is necessary to improve the shape of both ends of the stiffened girder section, and take measures such as adding air nozzles to improve the flow state of the airflow around, reduce vortex shedding, and make the cross section tend to be streamlined. The central groove of the steel box stiffened girder is used to increase ventilation and reduce the pressure difference between the top and bottom of the stiffened beam. The flutter critical wind speed of the separated box girder with the central groove will be improved to a certain extent. Of course, this will increase the bridge tower and the cost of the substructure. The flutter stability of the bridge can also be improved by arranging deflectors, dampers or spoilers, central stabilizing plates and other measures on the stiffened beam section to change the flow state around the flow.

The single-leaf hyperboloid space cable system suspension bridge is suitable for super-long-span strait suspension bridges of 3,000 to 5,000 meters. The stiffening beam should be a ventilated truss-type stiffening beam, and a ventilation belt should be installed in the middle of the section to reduce the pressure on the top and bottom of the stiffening beam. Poor, increase its flutter critical wind speed. In order to further strengthen the wind-resistant stability of the suspension bridge with the single-leaf hyperboloid space cable system, it is recommended to set up carbon fiber reverse cables to hold the truss-type stiffened beam and the single-leaf hyperboloid space cable system, and the carbon fiber reverse cables should be firmly fastened to the truss stiffeners The ring girders are reinforced with elliptical steel structures, and carbon fiber reverse cables are anchored in the concrete of the pylons. Set up a computer-controlled mechanical retractable device to interfere with the wind-induced vibration form of the suspension bridge. When encountering a typhoon, the carbon fiber reverse cable is tightened on the windward side, and the carbon fiber reverse cable is relaxed on the leeward side, so as to improve the suspension bridge of the single-leaf hyperboloid space cable system. wind stability.

(8) Install rigid central buckle and deck pavement

In order to strengthen the collaborative work ability of the single-leaf hyperboloid space cable system and the stiffening beam, in the mid-span area, a portal-type steel frame type rigid central buckle should be installed, and the rigid buckle connects the stiffening beam with the elliptical steel structure reinforcing ring beam , the torsional vibration of the stiffening beam and the torsional vibration of the space cable system can be coupled to a certain extent, and the torsional vibration of the space cable and the stiffening beam can be coupled to a certain extent with the lateral horizontal vibration, so as to improve the suspension bridge of the space cable system The spatial stiffness of the bridge enhances the wind resistance stability of the long-span suspension bridge.

At the mid-span, two elliptical steel structure reinforced ring girders with a distance of about 3 to 4 meters can be installed to rigidly connect each other, so that a double-row portal-type steel frame rigid central buckle can be set at the mid-span. In the middle area, several gantry-type steel frame rigid buckles are installed at an interval of 100-120 meters. In the 1/4 area of the bridge span, several flexible cable buckles are installed at a distance of 120-150 meters to further strengthen the space rigidity of the space cable system suspension bridge and improve Wind Stability of Extra Long Span Strait Suspension Bridge.

Finally, install the bridge railings, pave the asphalt concrete bridge deck, improve the bridge deck drainage system, carry out bridge painting and coating construction, organize construction acceptance, and open to traffic.

Claims (1)

1. A super-long-span suspension bridge with a single-leaf hyperboloid space cable net main cable, including a cylindrical net space main cable (1), a bridge tower (2), a steel ring tower head (3), a suspender (5), Stiffened steel girders (6) and anchorages (8), the main cable of the tubular mesh space (1) is connected to the steel ring tower head (3) as the main cable of the suspension bridge, and the steel ring tower head (3) is set at At the top of the bridge tower (2), the stiffened steel girder (6) is suspended below the main cable (1) in the tubular reticulated space through the suspender (5), characterized in that the main cable (1) in the tubular reticulated space ) is composed of several steel wire cables intersecting in space, and its spatial configuration is a closed tube-shaped cable net formed by the drooping of the single-leaf hyperboloid space cable net. The steel wire cables of the tube-network space main cable (1) pass through the steel ring tower The reserved holes on the head (3), the two ends of the main cable (1) in the tubular mesh space are anchored in the anchorage (8), and multiple elliptical channels are arranged in the main cable (1) in the tubular mesh space along the longitudinal direction of the suspension bridge. Shaped steel ring beam (4), the steel wire cable of the main cable (1) in the cylindrical network space passes through the oval steel ring beam (4) and is fixedly connected with it, and the upper end of the suspender (5) is fixed on the oval steel ring beam (4), the lower end of the suspender (5) is connected to the stiffened steel beam (6), and several portal-type rigid central buckles (7) are arranged in the middle area of the suspension bridge, and the lower end of the portal-type rigid central buckle (7) is connected to the stiffened steel beam (6) connection, the upper end is connected with the oval steel ring beam (4).

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