Rocky stratum tunneling underground structure flash joist anchor draws just branch structure and construction method
The invention belongs to tunneling and underground engineering technique of design and construction field more particularly to a kind of rocky stratum tunneling
Lower structure flash joist anchor draws just branch structure and construction method.
With the development of the causes such as economic construction and national defence, the exploitation of the large space underground structure of different function disclosure satisfy that
It is continuously increased in China's urban construction with applying, such as subway station, underground power house and civil air defense constructions and installations.
Large Underground Structure is built in rocky stratum, mean level lateral pressure is limited, for the ease of using, reducing investment outlay
With easy for construction, generally use straight flange wall arch section structure.In wall rock condition preferably and under the conditions of be buried, tunneling is using new
Method construction difficult to understand, preliminary bracing use anchor pole+gunite concrete structure.But complex environment builds subway station and people's air defense work in city
When the Large Underground Structures such as journey, influenced by geological conditions and buried depth limitation, the stratum that general tunnel or underground structure pass through is
Entirely, strong, middle weathered rock formation, developmental joint fissure, Grades of Surrounding Rock are IV~V grades.General subway station uses two layers or three layers
（Transfer stop）Design, for the height of straight flange wall in 8~15m, the isostructural straight peripheral wall height of underground power house is likely to be breached 30~40m.
For in the shallower soft stratum of buried depth or straight peripheral wall height is more than the Large Underground Structure of 15m, the place of high straight flange wall
Reason is exactly the key points and difficulties position in engineering construction, mishandling to be easy to cause the engineering accidents such as landslide, unstability.
Simultaneously as tunnel is still in rocky stratum, the intensity of rock mass is much larger than the soil body, and straight flange wall excavation in tunnel is applied
It also needs to take blasting construction method in work.Therefore, in the structural shape and scheme choice of high straight flange wall, guarantee should be based oneself upon
Under conditions of safety, while considering construction efficiency and economic benefit, uses construction method rapidly and efficiently as possible.
For the underground structure of high side wall in weak rocky stratum, abutment wall supporting construction generally uses grid steel frame or type
Steel steelframe combination gunite concrete and anchor pole form preliminary bracing structure, and currently used construction method is shallow burial hidden digging.
The construction method that high straight flange wall construction is most suitable in shallow burial hidden digging is undoubtedly benching tunnelling method, but by wall rock condition, buried depth and week
The influence of surrounding environment factor, benching tunnelling method construction is often it is difficult to ensure that abutment wall rock mass and stable structure, and Deformation control energy force difference.This
When construction in mainly using intersect median septum（CRD）, two side-wall pilot tunnel, the substeps cross-cut such as the holes middle hole Fa Hece method method,
These construction methods are required for that a large amount of lateral and vertical temporary support is arranged to realize that substep subtracts high cross-cut, and tunnel span is larger
When also need setting mid-board.It results in abandoned project amount so significantly to increase, while lateral and vertical temporary support setting, sternly
Construction space and construction speed are affected again, and work efficiency is extremely low, can not achieve big machineryization construction.Moreover, tunnel lower layer and
The temporary support on upper layer is difficult to retain before when ensuing blast, and also safe thing can be caused since explosion damages temporary support when serious
Traditional straight flange wall uses steelframe gunite concrete structure, applies man-hour requirement and is connect according to the height excavated every time
Leg is constructed, and the excavation of each step height increases the sedimentation of arch structure and stratum there are one the hanging operating mode in abutment wall bottom
Deformation, and there are certain security risks.Meanwhile each step abutment wall excavate after need the regular hour set up grid and into
Row construction of shotcrete, is unfavorable for country rock and the quick closure of structure, and working procedure also has certain intersection.
Stringent control under the mechanics feature and complicated environmental condition of the high straight flange wall construction in present invention combination shallow embedding lithostratigraphy
System requires, and to ensure that straight flange wall construction is stablized, improves construction efficiency, proposes a kind of rocky stratum tunneling underground structure flash joist anchor
Just branch structure and construction method are drawn, realizes that big machineryization carries out lithostratigraphy high retaining wall underground structure construction.
The technical solution adopted in the present invention is：A kind of first branch structure of rocky stratum tunneling underground structure flash joist anchor drawing,
It is characterized in that：Including steel-pipe pile, gunite concrete face layer, top ring beam, collar tie beam prestress anchorage cable, steel-pipe pile prestressed anchor
Rope, collar tie beam fixing piece, concrete fixing piece are sealed between the steel-pipe pile surface and adjacent steel-pipe pile by gunite concrete face layer
It closes, the top of the steel-pipe pile is longitudinally connected using top ring beam, and collar tie beam mud jacking steel pipe is embedded in the top ring beam, described
Collar tie beam prestress anchorage cable, steel-pipe pile prestress anchorage cable are vertically arranged, and one end of the collar tie beam prestress anchorage cable is installed on top circle
It is locked on beam and by collar tie beam fixing piece, the steel-pipe pile prestress anchorage cable is located at the lower section of the collar tie beam prestress anchorage cable, institute
Collar tie beam prestress anchorage cable is stated to be fixed on the gunite concrete face layer by concrete fixing piece.
The steel duct filling concrete mortar of the steel-pipe pile, the steel-pipe pile use diameter 219mm, thickness 8mm steel pipes,
Steel pipe 800~1500mm of spacing, steel pipe lower part are embedded in bottom of foundation ditch >=2m, and steel pipe top anchors into top ring beam depth >=1m.
The gunite concrete face layer is C20 gunite concretes face layer.
The top ring beam is reinforced concrete structure.
The collar tie beam fixing piece is channel steel or I-steel waist rail, and the concrete fixing piece is channel steel or I-steel waist rail.
The quantity of the collar tie beam prestress anchorage cable is together.
A kind of rocky stratum tunneling underground structure flash joist anchor draws the construction method of just branch structure, which is characterized in that including
（1）The arch preliminary bracing of underground structure upper layer is performed, according to strata condition using superpower slip casting ductule, grid steel
Frame and construction of shotcrete；
（2）After the completion of the preliminary bracing of upper layer arch, is excavated in abutment wall and set steel-pipe pile on the outside of position, made using down-the-hole drill
Hole, underthrust steel pipe, then pressure injection 1:1 cement mortar；
（3）Steel-pipe pile top rebars concrete top collar tie beam is poured, and buries collar tie beam mud jacking steel pipe in longeron, waits for top
Collar tie beam carries out supplement slip casting after reaching design strength, fills top ring beam bottom gap, reinforces top ring beam bottom country rock, simultaneously
Embedded casing is reserved in top ring beam applies prestress anchorage cable condition；
（4）Collar tie beam prestress anchorage cable and collar tie beam fixing piece are applied in top ring beam position, collar tie beam prestress anchorage cable is first
Road anchor cable carries out tensioning and anchoring by design requirement；
（5）The structure bottom step soil body is excavated apart from sidewall profile certain distance kerve, is not less than 1.5m models close to abutment wall
Interior Mining in Rock Mass photoface exploision or non-explosive excavation are enclosed, the layer supporting of abutment wall gunite concrete face is applied when excavating, is excavated to the
Steel-pipe pile prestress anchorage cable and waist rail are applied at two anchor cable positions, tensioning and anchoring are carried out by design requirement；
（6）Repeating said steps（5）Continue to be layered and excavate rock mass downwards, applies abutment wall gunite concrete face layer and anchor cable branch
Shield so far forms flash joist anchor and draws just branch structure until being excavated to underground structure substrate absolute altitude.
The step（2）Middle steel pipe pile driving construction is constructed using hole is jumped.
Beneficial effects of the present invention are：
1, rocky stratum tunneling underground structure flash joist anchor of the invention draws just branch structure and construction method, anchor to draw just branch knot
Structure is combined and is formed by steel-pipe pile, gunite concrete face layer, top ring beam, collar tie beam prestress anchorage cable, steel-pipe pile prestress anchorage cable, is fitted
For the straight flange wall preliminary bracing structure of weak rocky stratum Large span tunnel and underground structure, straight flange wall construction is stablized, and width is provided
Spacious space and raising construction efficiency；
2, construction applies steel-pipe pile in tunneling space, reinforcing bar is used at the top of steel-pipe pile in advance using the theory of open-cut foundation ditch
The connection of concrete collar tie beam is integral, then carries out underground structure lower layer excavation, and gunite concrete face layer is carried out when excavating abutment wall
And prestressing anchor support carries out underground structure main body reinforcing bar from lower to upper therewith until carrying out back cover behind underground structure bottom
Concreting removes prestress anchorage cable according to each layer structure construction height and monitoring measurement result；
3, the rocky stratum tunneling underground structure flash joist anchor in the present invention draws first branch structure to have structure type simple, holds
Loading capability is strong, and control deformability is good, reduces abandoned project amount, convenient and quick construction and construction period can provide open operation
The features such as space, construction organization facilitates；
4, the rocky stratum tunneling underground structure flash joist anchor in the present invention draws the construction method of just branch structure, the engineering method work
Skill is simple and convenient to operate, and well controls stratum deformation, and can be that entire underground structure engineering construction realizes that big machinery is turned into industry
Offer condition improves work efficiency, saves project cost；
5, the present invention provides a kind of shallow embedding or the high side wall branch in weak rocky stratum Large span tunnel or Large Underground space
The combination application of the multinomial technology of protection structure form, construction method and innovation, structure is reasonable, construction procedure it is simple and implement into
Degree is fast, solves that weak rocks quality floor height straight flange wall hole room stability is poor, and traditional steelframe and temporary support structures form are complicated,
Construction efficiency and environmental condition are poor, and stratum deformation is larger in digging process, and construction safety risk is big and construction organization inconvenience etc.
Many problems have preferably expanded the application space of Excavation Method Under Shallow, are later shallow buried covered excavation high retaining wall underground knot
The design and construction of structure provides new approaches, has higher reference value.
6, it in the case where high side wall steel pipe anchor draws just branch structural defence, safely and fast completes tunnel lower part excavation and agent structure is poured
Description of the drawings
Fig. 1 is the structural diagram of the present invention；
Fig. 2 is the construction schematic diagram of steel-pipe pile in the present invention；
Fig. 3 is the construction schematic diagram of top ring beam in the present invention；
Fig. 4 is the construction schematic diagram of Girth prestress anchorage cable of the present invention；
Fig. 5 is that anchor of the present invention draws just branch structure abutment wall lower layer's bench excavation and supporting construction schematic diagram；
Fig. 6 is that the anchor of the present invention draws just branch structure abutment wall substrate construction schematic diagram.
Specific implementation mode
The invention will be further described below in conjunction with the accompanying drawings：
In figure, 1- steel-pipe piles, 2- gunite concretes face layer, 3- top ring beams, 4- collar tie beam prestress anchorage cables, 5- steel-pipe piles are pre-
Stress anchor cable, 6- collar tie beam fixing pieces, 7- concrete fixing pieces, 8- collar tie beam mud jacking steel pipes, the preliminary bracing of the arch 9-.
As shown in Figure 1, a kind of rocky stratum tunneling underground structure flash joist anchor draws just branch structure, including steel-pipe pile 1, injection
Concrete topping 2, top ring beam 3, collar tie beam prestress anchorage cable 4, steel-pipe pile prestress anchorage cable 5, collar tie beam fixing piece 6, concrete are solid
Determine part 7, closed by gunite concrete face layer 2 between 1 surface of steel-pipe pile and adjacent steel-pipe pile 1, the top of steel-pipe pile 1 is using top
Portion's collar tie beam 3 is longitudinally connected, and collar tie beam mud jacking steel pipe 8, collar tie beam prestress anchorage cable 4, steel-pipe pile prestressed anchor are embedded in top ring beam 3
Rope 5 is vertically arranged, and one end of collar tie beam prestress anchorage cable 4 is installed in top ring beam 3 and is locked by collar tie beam fixing piece 6, steel pipe
Stake prestress anchorage cable 5 is located at the lower section of collar tie beam prestress anchorage cable 4, and collar tie beam prestress anchorage cable 4 is fixed on by concrete fixing piece 7
On gunite concrete face layer 2.
The steel duct filling concrete mortar of steel-pipe pile 1, steel-pipe pile 1 is using diameter 219mm, thickness 8mm steel pipes, between steel pipe
Away from 800~1500mm, steel pipe lower part is embedded in bottom of foundation ditch >=2m, and steel pipe top anchors into 3 depth of top ring beam >=1m.
Gunite concrete face layer 2 is C20 gunite concretes face layer.
Top ring beam 3 is reinforced concrete structure.
Collar tie beam fixing piece 6 is channel steel or I-steel waist rail, and concrete fixing piece 7 is channel steel or I-steel waist rail.
The quantity of collar tie beam prestress anchorage cable 4 is together.
Collar tie beam prestress anchorage cable 4, steel-pipe pile prestress anchorage cable 5 longitudinal pitch according to steel-pipe pile 1 determine, vertically away from
It should be calculated and be determined according to practical geologic parameter from, parameters such as length, diameter, anchorage depth and prestressing force size.
Above-mentioned rocky stratum tunneling underground structure high side wall steel pipe anchor draws first branch structure, the structure drafted to can be used for tunnel
With the straight flange wall preliminary bracing of 8~30m of underground structure height, should ensure that vertical precision when steel pipe is set, bottom answer build-in in
On firm rock foundation, intensification and consolidation process otherwise should be carried out.
A kind of rocky stratum tunneling underground structure flash joist anchor draws the construction method of just branch structure, includes the following steps：
（1）Underground structure upper layer arch advance support and arch preliminary bracing 9 are performed, advance support can be according to strata condition
Using advance anchor bolt, superpower slip casting ductule or pipe shed support, arch preliminary bracing 9 is applied using grid steel frame and gunite concrete
Work, arch preliminary bracing 9 should close cyclization in time；
（2）It is excavated in abutment wall and sets steel-pipe pile 1 on the outside of position, putting distance outside should determine according to construction precision and error, beat
If the circular hole of diameter 250mm is first made when steel-pipe pile 1 with down-the-hole drill, underthrust diameter 219mm, thickness 8mm steel pipes, pipe shaft drill straight diameter
20mm apertures, quincuncial arrangement, then pressure injection 1:1 cement mortar fills the gap between steel duct and steel pipe and pore-forming, steel
Pile pile 1 longitudinal pitch 800mm, bottom building-in depth 2.5m, top are embedded in 3 1.2m of top ring beam, the drilling of steel-pipe pile 1 take every
Pile driving construction；
（3）Pour the top ring beam 3 of steel-pipe pile 1, every section of longitudinal length about 10m, 3 size 1.5m × 1.8m of top ring beam,
Steel pipe is welded with ring beam reinforcing steel bar, and collar tie beam mud jacking steel pipe 8 is buried in top ring beam 3, waits for that 3 concrete of top ring beam reaches
Supplement slip casting is carried out after design strength, fills longeron bottom gap, reinforces longeron bottom country rock, while being buried in top ring beam 3
4 condition of collar tie beam prestress anchorage cable is applied if casing is reserved, the also foundation longitudinal beam as arch secondary lining of top ring beam 3；
（4）First of anchor cable i.e. collar tie beam prestress anchorage cable 4 is applied, first of anchor cable is arranged in steel-pipe pile 1 and top longitudinal beam
It overlaps in range, using 3 φ s15.2 steel strand wires, pre-applied force 200KN transfers steel strand wires after pore-forming, and installation collar tie beam fixing piece 6 is pressed
Design requirement carries out tensioning and anchoring, and anchor cable longitudinal pitch combination steel-pipe pile 1 is arranged as 1.6m, and vertical 3~4m of spacing is together；
（5）The structure bottom step soil body is excavated apart from sidewall profile certain distance kerve, is not less than 1.5m models close to abutment wall
Interior Mining in Rock Mass photoface exploision or non-explosive excavation are enclosed, 2 supporting of layer of gunite concrete face are applied when excavating, are excavated to second
0.5m applies collar tie beam prestress anchorage cable 4 and concrete fixing piece 7 under anchor cable position, and tensioning and anchoring are carried out by design requirement；
（6）Continue to excavate rock mass downwards, when excavation answers longitudinal framing, vertical layered, symmetrical to excavate, while applying abutment wall spray
Concrete layer 2 and cable bolting are penetrated, until being excavated to underground structure substrate absolute altitude, appearance infiltration is larger between pile lining in digging process
When, timely ejection for water plugging is answered, high side wall steel pipe anchor structure is ultimately formed.
（7）It is excavated to timely flat bottom after substrate, bed course and waterproof layer is applied, then applies secondary lining from lower to upper
Reinforced concrete structure removes prestress anchorage cable according to each layer structure construction height and monitoring measurement result.
Structure of the invention and engineering method are suitable for the Gao Zhi of the underground spaces such as rocky stratum large span section subway station or tunnel
Abutment wall supporting and construction, should strictly control excavation height in construction, weak blast reinforces Vault settlement and abutment wall horizontal distortion prison
1 embodiment of the present invention is described in detail above, but the content is only the preferable implementation of the present invention
Example should not be construed as limiting the practical range of the present invention.It is all according to all the changes and improvements made by the present patent application range
Deng should all still fall within the scope of the patent of the present invention.