Summary of the invention
The present invention makes to solve the above-mentioned technical problem that exists in prior art, its object is to provide a kind of and effectively prevents the double-vane outrigger preliminary bracing structure and method for tunnel construction thereof of facing upward the large deformation such as liner craks, surrouding rock deformation, ground settlement in slope, cover arch, hole.
According to an aspect of the present invention, a kind of double-vane outrigger preliminary bracing structure is provided, described supporting and protection structure comprises the bow member arranged along tunnel inner wall, wherein, described bow member is fixed with along tunnel depth direction the multiple seamless steel pipe and multiple steel floral tube that are crisscross arranged with a determining deviation, described seamless steel pipe or steel floral tube are arranged on haunch place, tunnel, one end to be fixed on bow member and to reserve grouting port, the other end injects in country rock, be inserted with reinforcing bar in described seamless steel pipe and be filled with cement mortar between steel pipe and reinforcing bar, described steel floral tube tube wall has grout outlet, cement paste is injected in described steel floral tube, slip casting is carried out to tunnel surrounding, the diameter of described seamless steel pipe and steel floral tube and spacing are determined according to the country rock situation of tunnel portal, and for the country rock of rich water, shallow embedding or weakness, the spacing of employing is within the scope of 0.8m-1.5m, described supporting and protection structure also comprises the grouting tube being arranged on tunnel bottom or the local Grouting Pipe be arranged near tunnel vault, the diameter of the steel floral tube at described haunch place is greater than the diameter of tunnel bottom grouting tube or vault local Grouting Pipe.
Described supporting and protection structure, wherein, the angle of described seamless steel pipe or steel floral tube and horizontal plane is within the scope of 0 °-30 °.
Described supporting and protection structure, wherein, the diameter of described seamless steel pipe and steel floral tube and spacing are determined according to the country rock situation of tunnel portal, the country rock of Fu Shui, shallow embedding or weakness, adopt larger diameter and less spacing.
Described supporting and protection structure, wherein, described seamless steel pipe and steel floral tube are welded on described bow member.
According to another aspect of the present invention, provide a kind of double-vane outrigger preliminary bracing structure of aforementioned any one technical scheme that adopts to carry out the method for tunnel construction of constructing, described construction method comprises:
One end of seamless steel pipe and steel floral tube is laterally interlocked in the country rock at insertion haunch place, tunnel;
Erection bow member, is fixed on bow member by the other end of seamless steel pipe and steel floral tube;
Reinforcing bar will be inserted in described seamless steel pipe and fill closely knit by cement mortar, injecting cement paste by described steel floral tube, slip casting is carried out to tunnel surrounding;
Slip casting steel floral tube is set at tunnel bottom, utilizes cement paste to tunnel bottom slip casting or local Grouting Pipe is set near tunnel vault, utilizing cement paste to carry out slip casting to the country rock of tunnel vault;
Along tunnel inner wall sprayed mortar, form the first lining in tunnel;
Erection Temporary invert, accelerates the velocity of approach of secondary lining chassis, carries out the excavation got out of a predicament or an embarrassing situation in tunnel, after excavation of getting out of a predicament or an embarrassing situation completes, and the permanent inverted arch of construction in time, build secondary and just build, ring is closed in tunnel;
The number that described seamless steel pipe and steel floral tube are arranged on tunnel biased side is larger than its number in non-biased side, and it is little in the spacing of non-biased side for gap ratio.
Described construction method, wherein, described seamless steel pipe and steel floral tube insert the degree of depth of country rock in the scope of 8m-15m, or embedding stabilizing surrounding rock segment length meets anchoring requirement.
Double-vane outrigger preliminary bracing structure of the present invention is staggeredly equipped with the seamless steel pipe and steel floral tube that embed country rock at the haunch place in tunnel, both steel floral tube cement injection shutoff crevice water can have been utilized, the country rock and just block distortion and tunnel integral sinking that cause is oozed under preventing underground water, the nail fourth of the twelve Earthly Branches of seamless steel pipe can be utilized again to act on the frictional resistance increased between rock stratum, strengthen and just builds supporting intensity.Utilize grouting tube to improve bearing capacity of foundation soil in tunnel bottom slip casting, prevent tunnel integral sinking.Utilize local Grouting Pipe in tunnel top slip casting, the different rock-layers shutoff rock seepage of consolidation tunnel top country rock.
Detailed description of the invention
Come below with reference to accompanying drawings to be described in detail each embodiment of the present invention.
Fig. 1 shows the schematic diagram that double-vane outrigger preliminary bracing structure of the present invention is arranged along tunnel inner wall, as shown in the figure, described supporting and protection structure comprises the bow member 110 arranged along tunnel 100 inwall, wherein, described bow member 110 is provided with the seamless steel pipe 130 and steel floral tube 120 that are crisscross arranged with a determining deviation along tunnel depth direction, described seamless steel pipe 130 and steel floral tube 120 are arranged on the haunch place in tunnel 100, one end to be welded on bow member 110 and to reserve grouting port 121, in the country rock in one end reeve tunnel 100 in addition, be inserted with reinforcing bar in described seamless steel pipe 130 and be filled with cement mortar between steel pipe and reinforcing bar, the angle of described seamless steel pipe 130 and steel floral tube 120 and horizontal plane is within the scope of 0 °-30 °.Be inserted with reinforcing bar in described seamless steel pipe 130 and fill closely knit by cement mortar, adding the shear strength of steel pipe, not only reinforce adjoining rock but also reduce bow member distortion and sedimentation.The tube wall of described steel floral tube 120 has grout outlet, in above-mentioned steel floral tube, injects cement paste, slip casting is carried out to tunnel surrounding, the rock stratum that not only consolidation is different but also shutoff rock crack water and seepage in underground.Steel floral tube 120 and seamless steel pipe 130 laterally run through tunnel inside and outside wall, be equivalent to the both wings in tunnel, so be called double-vane outrigger preliminary bracing structure, described supporting and protection structure to top bar 150 share load, controlling distortion has very large effect, define 150 horizontal, longitudinal beam bases of topping bar, solve arch springing ground weak, Lack of support, the shortcoming of sedimentation after soaking by underground water.
Preferably, described seamless steel pipe 130 and steel floral tube 120 insert the degree of depth of country rock within the scope of 8m-15m, or embedding stabilizing surrounding rock segment length meets anchoring requirement.
In addition, preferably, described double-vane outrigger preliminary bracing structure is also included in the grouting tube 140 at the bottom of insertion tunnel that tunnel bottom is arranged, and utilizes grouting tube 140 to improve bearing capacity of foundation soil in tunnel bottom slip casting, prevents tunnel integral sinking.
Fig. 2 is the schematic perspective view of double-vane outrigger preliminary bracing structure of the present invention, as shown in the figure, seamless steel pipe 130 and steel floral tube 120 are welded on bow member 110 so that certain spacing is laterally interlaced, namely, often be provided with a steel floral tube 120 in the middle of adjacent two seamless steel pipes 130, often arrange a seamless steel pipe 130 in the middle of adjacent two steel floral tubes 120, the arrangement of described seamless steel pipe 130 and steel floral tube 120 is symmetrical along tunnel haunch.Described seamless steel pipe 130 and steel floral tube 120 diameter and spacing are determined according to the country rock situation of tunnel portal, and the country rock of Fu Shui, shallow embedding or weakness, adopts larger diameter and less spacing.Preferably, described spacing is 0.8m-1.5m.When tunnel top country rock is by underground water mitigation detrition, local Grouting Pipe 170 can be set near tunnel vault, for the wall rock grouting near tunnel vault, consolidation different rock-layers shutoff rock seepage.
Preferably, as shown in Figure 2, when tunnel exists bias voltage, when namely the compressive stress of side, tunnel is greater than the compressive stress of opposite side, the seamless steel pipe 130 arranged than non-biased side 112 in biased side 111 and the spacing of steel floral tube 120 little, quantity is many.
The diameter of described steel floral tube 120 and seamless steel pipe 130 can be the same or different, the diameter of described steel floral tube 120 is preferably greater than the diameter of tunnel bottom grouting tube 140, the diameter of described local Grouting Pipe 170 is preferably not less than the diameter of grouting tube 140, this is because the grouting tube 140 of tunnel bottom is stressed minimum.
Fig. 3 is the flow chart of the construction method in the tunnel with double-vane outrigger supporting and protection structure of the present invention, and composition graphs 1 and Fig. 3 describe construction method of the present invention and comprise the steps:
First, in step S310, benching tunneling method excavation is adopted to tunnel, after 150 excavations of topping bar complete, laterally interlock at haunch place, tunnel and insert seamless steel pipe 130 and steel floral tube 120;
After seamless steel pipe 130 and steel floral tube 120 have been arranged, in step s 320, along tunnel inner wall erection bow member 110, and seamless steel pipe 130 and steel floral tube 120 to be fixed on bow member 110 and to reserve grouting port 121;
After preliminary bracing has been set up, in step S330, in described seamless steel pipe 130, insert reinforcing bar and fill closely knit by cement mortar, in steel floral tube 120, injecting cement paste, slip casting is carried out to tunnel surrounding.
Preferably, also comprise in step S310 to S330, slip casting steel floral tube 140 is set at tunnel bottom, grouting tube 140 quincuncial arrangement, utilize cement paste in 1:0.5 to 1:1 scope to slip casting bottom tunnel, grouting pressure is determined according to field trial, such as, first to tunnel bottom with certain grouting pressure (such as, 2MPa) slip casting, observe the lower milliosmolarity of cement grout, if lower milliosmolarity reaches requirement, then adopt above-mentioned grouting pressure.If lower milliosmolarity is less than normal, then increase grouting pressure.If lower milliosmolarity is bigger than normal, then reduce grouting pressure.Utilize said method to satisfy rising pouring slurry, effectively can improve base bearing capacity.
In addition, preferably, also comprise in step S310 to S330, local Grouting Pipe 170 is set near tunnel vault, to tunnel top slip casting, unity different rock-layers shutoff seepage in underground.
After preliminary bracing slip casting completes, in step S340, along tunnel inner wall sprayed mortar, form the first lining 101 in tunnel.
After tunnel just serves as a contrast 101 formation, in step S350, timely erection Temporary invert, accelerate the velocity of approach of secondary lining chassis, carry out tunnel get out of a predicament or an embarrassing situation 160 excavation, after 160 excavations of getting out of a predicament or an embarrassing situation complete, in time the permanent inverted arch of construction, build secondary lining, ring is closed in tunnel, applies inverted arch and closes into two lining 102 (Fig. 1 illustrates) intensity that ring further enhancing the supporting of double-vane outrigger in time.
Preferably, after step S350, also comprise the step of the ponding getting rid of arch springing place, prevent the infiltration in tunnel from soaking arch springing.
According to another embodiment of the present invention, above-mentioned for the present invention construction method is applied to the tunnel of a certain rich water, shallow embedding, weak surrounding rock, particularly, first, analyze hole landform, geology, the hydrology in tunnel, the lithology of the Shallow Section in tunnel is intense weathering munstone burning into sand rock, shale, half rock half soil, and closely knit earthy or closely knit earthy are caught broken stone; Hole top surface is rice field; Entrance section of tunnel rock mass be in-thick-bedded sandstone, silty etc., occurrence is 243 ° of ∠ 73 °; From hole landform, on the left of left hole, covering layer is thicker, and on the right side of left hole and right hole covering layer is thinner, exists by left side bias voltage to the right.
Then, accordingly, determining that tunnel initial-stage supports may produced problem, such as, broken with the rock decay of inducer due to shallow-buried sector, when digging, top, hole easily loosens distortion; Hole top surface is rice field, has water soaking throughout the year, oozes and makes top, hole covering layer reach water saturation state, not only increase the seepage water pressure of underground water, and covering layer unit weight is increased, add the load of tunnel inside lining under surface water; Country rock before not excavating around tunnel is in stress stability state, after tunnel excavation there is face high up in the air in tunnel location, in addition the seepage flow of underground water had both softened rock stratum and had again reduced frictional resistance between rock stratum, caused the power that just a steelframe is subject to not only to have initial stress to also have the sliding force of rock stratum; After tunnel excavation, there is the bias voltage to the right from left side, then bias voltage is all born by preliminary bracing, and seepage action of ground water again reduces the bearing capacity of substrate, therefore when initial stage supporting parameter is not enough, easily causes flexural deformation and the tunnel bulk settling of preliminary bracing.
Subsequently, for the problems referred to above, tunnel initial-stage braced structures is set, namely, laterally being crisscross arranged at haunch place, tunnel is welded on for the seamless steel pipe 130 on frame and steel floral tube 120, owing to there is bias voltage from left to right, the described seamless steel pipe 130 arranged on the right side of tunnel and steel floral tube 120 number more, spacing is less; Because tunnel vault is rice field, local Grouting Pipe 170 is set near tunnel vault; Because seepage action of ground water reduces the bearing capacity of substrate, grouting tube 140 is set at tunnel bottom.
Finally, according to method for tunnel construction of the present invention, constructed in tunnel.Be provided with multiple settlement observation point to described Tunnels in Shallow Buried location before construction, observed result shows, and surface subsidence amount is within the scope of 2cm-16cm, and after construction, the earth's surface of observation is heavy will measure at below 6mm.So double-vane outrigger preliminary bracing structure of the present invention and method for tunnel construction thereof can reduce the settling amount on earth's surface, tunnel effectively.
Although disclosed content shows exemplary embodiment of the present invention above, it should be noted that under the prerequisite not deviating from the scope of the present invention that claim limits, can multiple change and amendment be carried out.Need not perform with any particular order according to the function of the claim to a method of inventive embodiments described herein, step and/or action.In addition, although element of the present invention can describe or requirement with individual form, also it is contemplated that multiple, is odd number unless explicitly limited.