Segmental beam backward construction method

Abstract

The present application relates to a kind of segmental beam construction methods, especially a kind of segmental beam retreating type construction method, comprising the following steps: S1, enlarge foundation construction;S2, temporary steel pipe support erection, for bridge machine equipment 2, 3, 4 legs of station position;S3, bridge machine assembly and debugging;S4, bridge machine retreating type hole;S5, segmental beam erection.A kind of segmental beam retreating type construction method makes bridge machine along long distance erection direction assembly, debugging, first erection 24~31# beam span, can save trestle lease fee, then bridge machine retreats to the turning field and starts point and carries out retreating type segmental beam erection under the condition that bridge machine does not turn around second assembly, saves bridge machine second turn around assembly, debugging time, saves erection cost, advances erection period.

Description

TECHNICAL FIELD

[0001] The present application relates to a segmental beam construction method, in particular to a segmental beam backward construction method. BACKGROUND

[0002] The segmental beam erection of Wuxi-Jiangyin intercity rail transit engineering Xuyan section totals 68 holes, which underpasses Beijing-Shanghai high-speed rail and then overpasses the boundary river to Yaqiao station (already built) from Xuxiake station. The distance between the beam bottom of Beijing-Shanghai high-speed rail and the top surface of the pad stone of the under-construction project is 8.7 m, and the minimum distance between the highest point of the bridge erecting machine and the top surface of the pad stone is 10.3 m. Therefore, the bridge erecting machine cannot underpass the Beijing-Shanghai high-speed rail and needs to be transferred and assembled.

[0003] After site investigation, there are three 110kv high-voltage lines between 20# and 21#. Due to the insufficient minimum safety distance between the lowest point of the high-voltage line and the extension of the crane boom in the bridge erecting machine assembly process, 20#-22# piers cannot be used as the transfer erection point. The 8m distance in the large mileage direction of 25# pier is a navigable river, and there is no high-voltage line above 23#-25# piers, and the site meets the operation requirements of large-tonnage cranes. Therefore, the bridge erecting machine assembly site can be located at 23#-25# piers.

[0004] The original segmental beam erection scheme after the transfer of the bridge erecting machine is as follows: first, the bridge erecting machine is assembled and debugged at 23#-25# piers, and then 24#-20# beam spans are erected; second, the bridge erecting machine is returned to 23#-25# piers and assembled and debugged again, and the bridge erecting machine is erected from 24# pier.

[0005] However, this method has a long construction period, and the bridge erecting machine increases the turning time by about 30 days, and the cost of bridge erecting machine rental and second assembly is high. SUMMARY

[0006] To solve the above problems, the present application provides a segmental beam backward construction method which can save the second turning assembly and debugging time of the bridge erecting machine, save the erection cost, and shorten the erection period. The specific technical scheme is as follows:

[0007] A segmental beam backward construction method, comprising the following steps:

[0008] S1, expanding foundation construction;

[0009] S2, temporarily setting up a steel pipe support for the station of No. 2, No. 3 and No. 4 legs of the bridge erecting machine;

[0010] S3, assembling and debugging the bridge erecting machine;

[0011] S4, backward passing through the hole by the bridge erecting machine;

[0012] S5, segmental beam erection.

[0013] Preferably, in the step S1, the enlarged foundation construction is linked with the existing pile cap by using the anchorage technology, and the enlarged foundation is laid out according to the design drawing, the formwork is erected, and the concrete is poured.

[0014] Preferably, the temporary support in the step S2 comprises an upper cross beam, a steel pipe column, an inter-column flat link and a pier connecting device; according to the stress characteristics of the temporary support and the layout design requirements of the overall structure, the overall structure of the support adopts a pipe pile plus cross link frame inter-column flat link structure, and according to the stress conditions of the 2nd, 3rd and 4th legs, 4 columns are arranged at the positions directly below the legs, and the upper ends of the columns are arranged with the upper cross beam.

[0015] Preferably, the step S4 of the back-off type hole passing of the bridge erecting machine comprises the following steps:

[0016] Step one: after the bridge erecting machine is assembled, the bridge erecting machine is erected to the predetermined construction position, and then the back-off is started;

[0017] Step two: the 1st leg is disassembled and folded to meet the height of the upper bridge deck;

[0018] Step three: the bridge erecting machine is back-off in the reverse direction in the hole passing posture, and the 4th leg is supported on the temporary support column;

[0019] Step four: the bridge erecting machine continues to back-off, and the main beam is in place;

[0020] Step five: the 2nd and 3rd legs are sequentially transported backward; the 3rd leg is supported on the temporary column;

[0021] Step six: the bridge erecting machine is back-off in the reverse direction in the hole passing posture; the 4th leg is supported on the temporary support column;

[0022] Step seven: the 2nd and 3rd legs are sequentially transported backward; the 3rd leg is supported on the temporary column;

[0023] Step eight: the bridge erecting machine is back-off in the reverse direction in the hole passing posture; the 4th leg is supported on the temporary support column; the steel pipe column of the 24th pier is disassembled;

[0024] Step nine: the bridge erecting machine erects the 23rd-24th pier box girder;

[0025] Step ten: the 2nd and 3rd legs are sequentially transported backward; the 3rd leg is supported on the temporary column; the steel pipe column of the 23rd pier is disassembled;

[0026] Step eleven: the bridge erecting machine is back-off in the reverse direction in the hole passing posture; the 4th leg is supported on the temporary support column; the 22nd-23rd pier box girder is erected;

[0027] Step twelve: the back-off operation is repeated, and the 21st-22nd pier box girder is erected

[0028] Step thirteen, the bridge erecting machine retreats to the last hole, and the 4# supporting leg does not retreat; after the retreat, the rear main beam is in a cantilever state, and the overhead traveling crane cannot travel to the rear cantilever main beam;

[0029] Step fourteen, the steel pipe column of the 21# pier is removed; and the normal beam erecting operation is carried out;

[0030] Step fifteen, after the beam erecting is completed, the reverse operation of the above steps is carried out to restore the normal construction direction;

[0031] Step sixteen, the holes are passed forward hole by hole until the normal construction position is returned to the front to restore the normal construction.

[0032] Compared with the prior art, the present application has the following beneficial effects:

[0033] The segmental beam retreat type construction method provided by the present application makes the bridge erecting machine assemble and debug along the long distance erecting direction, erects the 24-31# beam spans first, saves the trestle rental fee, then retreats to the erecting point at the turning field, erects the segmental beam in the retreat type under the condition that the bridge erecting machine does not turn around for secondary assembly, saves the secondary turning around assembly and debugging time of the bridge erecting machine, saves the erecting cost, and shortens the erecting period.

[0034] The construction period can be reasonably compressed, and the retreat type beam erecting saves 30 days of the period of the segmental beam erecting.

[0035] The comprehensive economic benefit is high: the bridge erecting machine rental fee is 8000 yuan / day, 8000*(20+7)=21.6 million yuan, the turning around assembly cost is 50 million yuan, the steel trestle rental fee is 57.19*1300*1.09=8.2 million yuan, and the total cost saving is 79.8 million yuan. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is the flow chart of the present application;

[0037] Figure 2 is the plane layout drawing of the underpassing Beijing-Shanghai high-speed rail;

[0038] Figure 3 is the elevation position drawing of the Beijing-Shanghai high-speed rail and the under-construction project;

[0039] Figure 4 is the segmental beam erecting erecting point plane position drawing;

[0040] Figure 5 is the steel pipe pile elevation drawing;

[0041] Figure 6 is the expanded foundation steel mesh;

[0042] Figure 7 is the 24# pier temporary steel pipe support elevation drawing;

[0043] Figure 8 is a plan view of the temporary steel pipe support of the 24# pier;

[0044] Figure 9 is an elevation view of the temporary steel pipe support of the 20-23# pier;

[0045] Figure 10 is a plan view of the temporary steel pipe support of the 20-23# pier;

[0046] Figure 11 is a view of the temporary steel pipe support;

[0047] Figure 12 is a view of the bridge machine assembly and debugging;

[0048] Figure 13 is a schematic view of step one;

[0049] Figure 14 is a schematic view of step two;

[0050] Figure 15 is a schematic view of step three;

[0051] Figure 16 is a schematic view of step four;

[0052] Figure 17 is a schematic view of step five;

[0053] Figure 18 is a schematic view of step six;

[0054] Figure 19 is a schematic view of step seven;

[0055] Figure 20 is a schematic view of step eight;

[0056] Figure 21 is a schematic view of step nine;

[0057] Figure 22 is a schematic view of step ten;

[0058] Figure 23 is a schematic view of step eleven;

[0059] Figure 24 is a schematic view of step twelve;

[0060] Figure 25 is a schematic view of step thirteen;

[0061] Figure 26 is a schematic view of step fourteen;

[0062] Figure 27 is a schematic view of step fifteen;

[0063] Figure 28 is a schematic view of step sixteen. DETAILED DESCRIPTION

[0064] The application will be further described in conjunction with the accompanying drawings.

[0065] The segmental beam is erected along the long mileage direction, the beam span length of 20-25# is 30m, the full length of the bridge machine is 92.9m, there are three high-voltage lines in the short mileage, and the long mileage is a navigable river. Due to the constraints of site conditions, 24-25# piers are used as the erection starting point after the site is changed, so the 20-24# segmental beam spans need to be erected in a backward manner.

[0066] As shown in Figures 1 to 28 , a segmental beam backward construction method comprises the following steps:

[0067] S1, expanding foundation construction;

[0068] According to the geological survey report and the bearing capacity calculation book, the bottom of the expanded foundation needs to be punched into a steel pipe pile. A DZ90 pile hammer is selected to meet the soil depth requirement of the steel pipe pile. When the steel pipe pile is constructed, the soil depth is mainly used, and the penetration depth is used for checking. The penetration depth requirement should be executed according to the specification requirements.

[0069] The 20#-24# pile cap is 5.8x5.8m. In order to meet the erection of the steel pipe support, a longxwidthxheight=2.55x7.4x1.5m expanded foundation is arranged on the short mileage side of the pile cap. The expanded foundation is linked with the existing pile cap by using the anchoring technology. The expanded foundation is arranged according to the design drawing, and the steel reinforcement mesh is arranged, the formwork is erected, and the concrete is poured.

[0070] S2, temporary steel pipe support erection, used for the station position of the bridge machine equipment No. 2, No. 3 leg, and No. 4 leg;

[0071] The temporary support includes an upper cross beam, a steel pipe column, a column interlink, and a pier connecting device. According to the stress characteristics of the temporary support and the overall structural layout design requirements, the overall structure of the support adopts a pipe pile plus a cross-link frame column interlink structure. According to the stress conditions of No. 2, No. 3, and No. 4 legs, four columns are arranged at the positions directly below the legs, and the upper ends of the columns are arranged with the upper cross beam. Meanwhile, considering the factor of the high pier, the connecting device with the pier is specially increased to enhance the stability of the temporary support. The pier connecting device adopts the form of No. 20 channel steel plus φ32 precision rolled threaded steel bar adjustment. Each set of support is arranged in two layers. At the contact position of the support and the pier column, a 2cm thick rubber pad is arranged to protect the pier body from being damaged.

[0072] The operation and use of the temporary support are relatively convenient. During construction, the installation is matched according to the height of the bridge and the size of each component of the temporary support.

[0073] Steel pipe column can be assembled again after the beam is removed, which can be recycled, so the steel pipe column is additionally increased by one set.

[0074] S3, assembling and debugging of the bridge erecting machine;

[0075] According to the assembling scheme of the bridge erecting machine, the bridge erecting machine is assembled and debugged, and after being accepted by the special inspection department, the general contractor, supervision, construction and other units organize the condition acceptance of the bridge erecting machine, and only after passing the acceptance can the segmental beam be erected.

[0076] S4, the bridge erecting machine retreats through the hole;

[0077] As shown in Figures 13 to 28 , the step S4 of the bridge erecting machine retreating through the hole comprises the following steps:

[0078] Step one, after the bridge erecting machine is assembled, it is erected to the designated construction position, and then it starts to retreat;

[0079] Step two, 1# leg is disassembled and folded to meet the height of the upper bridge surface;

[0080] Step three, the bridge erecting machine retreats through the hole in the reverse direction; the 4# leg is supported on the temporary support column;

[0081] Step four, the bridge erecting machine continues to retreat, and the main beam is in place;

[0082] Step five, 2#, 3# legs are transported backward one by one; the 3# leg is supported on the temporary support column;

[0083] Step six, the bridge erecting machine retreats through the hole in the reverse direction; the 4# leg is supported on the temporary support column;

[0084] Step seven, 2#, 3# legs are transported backward one by one; the 3# leg is supported on the temporary support column;

[0085] Step eight, the bridge erecting machine retreats through the hole in the reverse direction; the 4# leg is supported on the temporary support column; the steel pipe column of the 24# pier is disassembled;

[0086] Step nine, the bridge erecting machine erects the 23#-24# pier box girder;

[0087] Step ten, 2#, 3# legs are transported backward one by one; the 3# leg is supported on the temporary support column; the steel pipe column of the 23# pier is disassembled;

[0088] Step eleven, the bridge erecting machine retreats through the hole in the reverse direction; the 4# leg is supported on the temporary support column; the 22#-23# pier box girder is erected;

[0089] Step twelve, the retreat operation is repeated and the 21#-22# pier box girder is erected

[0090] Step thirteen, the bridge machine retreats to the last hole, and the 4# leg does not retreat; after the retreat, the rear main beam is in a cantilever state, and the overhead traveling crane cannot travel to the rear cantilever main beam;

[0091]

[0092] Step fourteen, the steel pipe column of the 21# pier is removed; and the normal beam erection operation is performed;

[0093] Step fifteen, after the beam erection is completed, the reverse operation of the above steps is performed to restore the normal construction direction;

[0094] Step sixteen, the holes are passed forward hole by hole until the front waiting beam erection position is returned to, and the normal construction is restored.

[0095] S5, segmental beam erection.

[0096] The same as the normal segmental beam erection process.

[0097] The technology is suitable for the retreat type segmental beam erection construction of the TP70 type bridge machine.

[0098] The technical principles of the present application are described above in combination with specific embodiments. These descriptions are only for explaining the principles of the present application, and cannot be explained as limiting the protection scope of the present application in any way. Based on the explanations herein, other specific embodiments of the present application can be conceived by those skilled in the art without creative labor, and these embodiments will fall within the protection scope of the claims of the present application.

Claims

1. A method for constructing segmental beams using a setback construction technique, characterized in that, Includes the following steps: S1. Expand foundation construction; S2. Temporary steel pipe supports are erected for the positioning of the No. 2, No. 3, and No. 4 outriggers of the bridge crane equipment; S3, Bridge erecting machine assembly and commissioning; S4, Bridge erecting machine retracting through the hole; S5. Segmental beam erection; The step S4, the bridge erecting machine retracting through the hole, includes the following steps: Step 1: After the bridge erecting machine is assembled, it is erected at the designated construction position and then begins to move backward; Step 2: Disassemble and fold out support leg No. 1 to meet the height requirements of the upper bridge deck; Step 3: The bridge erecting machine reverses backward through the hole in a through-hole posture; outrigger No. 4 is supported on the temporary support; Step 4: The bridge erecting machine continues to retreat until the main beam is in place; Step 5: Outrigger No. 2 and outrigger No. 3 are moved backward in sequence; outrigger No. 3 is supported on the temporary column; Step 6: The bridge erecting machine reverses backward through the hole in a through-hole posture; outrigger No. 4 is supported on the temporary support; Step 7: Outrigger No. 2 and outrigger No. 3 are moved backward in sequence; outrigger No. 3 is supported on the temporary column; Step 8: The bridge erecting machine reverses backward through the span in a span-crossing posture; outrigger No. 4 is supported on a temporary support; the steel pipe column of pier No. 24 is dismantled; Step 9: The bridge erecting machine erects the box girder for pier No. 23 and pier No. 24; Step 10: The No. 2 and No. 3 outriggers are moved backward in sequence; the No. 3 outrigger is supported on the temporary column; the steel pipe column of pier No. 23 is dismantled; Step 11: The bridge erecting machine reverses backward through the hole in the opposite direction; outrigger No. 4 is supported on the temporary support. Erecting the box girder for pier No. 22 and pier No. 23; Step 12: Repeat the backward operation and erect the box girder for pier No. 21 and pier No. 22; Step 13: The bridge erecting machine retracts to the last span, and the No. 4 outrigger does not retract. After retraction, the rear main beam is in a cantilever state. At this time, the overhead crane must not move onto the rear cantilever main beam. Step Fourteen: Remove the steel pipe columns of Pier No. 21; proceed with normal beam erection operations; Step 15: After the beam erection is completed, reverse the steps above to return to the normal construction direction; Step 16: Proceed through each hole one by one until you return to the position where the beam is to be erected, and resume normal construction.

2. The segmental beam retreat construction method according to claim 1, characterized in that, During the construction of the enlarged foundation in step S1, the rebar anchoring technology is used to connect it with the existing foundation. The enlarged foundation is constructed by laying out the steel mesh, erecting the formwork, and pouring the concrete according to the design drawings.

3. The segmental beam retreat construction method according to claim 1, characterized in that, The temporary steel pipe support in step S2 includes an upper crossbeam, steel pipe columns, inter-column horizontal bracing, and pier connection device. Based on the stress characteristics of the temporary steel pipe support and the overall structural layout design requirements, the overall structure of the support adopts a pipe pile plus horizontal bracing frame inter-column horizontal bracing structure. According to the stress conditions of legs 2, 3, and 4, four columns are set directly below each leg, and an upper crossbeam is arranged at the upper end of the column.

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