CN113638443A

CN113638443A - Construction process of underground comprehensive pipe gallery

Info

Publication number: CN113638443A
Application number: CN202111039826.5A
Authority: CN
Inventors: 曹凯飞; 张亮; 黄罗成; 丘旭源; 陈鹏; 曹斌; 温良杰; 李晓龙; 蒋永辉
Original assignee: CCCC Shanghai Dredging Co Ltd.
Current assignee: CCCC Shanghai Dredging Co Ltd.
Priority date: 2021-09-06
Filing date: 2021-09-06
Publication date: 2021-11-12

Abstract

The invention discloses a construction process of an underground comprehensive pipe gallery, which comprises the following procedures: excavating a foundation pit, constructing a pipe gallery main body and constructing a road surface; the foundation pit excavation process comprises the following steps: strengthening the pit bottom, supporting the foundation pit, dewatering the foundation pit and excavating the foundation pit; when the pit bottom reinforcing step is carried out, reinforcing the pit bottom by adopting a cement mixing pile and a PHC tubular pile; and when the step of supporting the foundation pit is carried out, steel sheet piles, steel enclosing purlins and horizontal supporting supports are adopted for supporting. The construction process of the pipe gallery main body comprises the following steps: the construction method comprises the following steps of cushion layer construction, bottom plate steel bar binding, bottom plate template erecting, bottom plate concrete pouring, side wall and top plate steel bar binding, side wall and top plate template erecting, side wall and top plate concrete pouring, formwork stripping concrete maintenance, waterproof engineering and foundation pit backfilling. The pavement construction process comprises the following steps: broken stone cushion layer construction, water stabilization layer construction and asphalt surface layer construction. The construction process of the underground comprehensive pipe gallery has the characteristics of good construction quality, time and labor conservation, construction cost reduction and good waterproof effect.

Description

Construction process of underground comprehensive pipe gallery

Technical Field

The invention relates to a construction process of an underground comprehensive pipe gallery.

Background

The city utility tunnel project is taken as a municipal infrastructure project in the initial development stage in China, and after a plurality of development bottlenecks, the city utility tunnel project has become a necessary trend of city development under the background of the national vigorous development of infrastructure construction. The utility tunnel is an underground space structure which is built underground in the city and used for accommodating public facility pipelines including electric power, communication, water supply, gas, drainage, heat supply and the like and has the facility functions of complete drainage, illumination, communication, monitoring and the like. The general cross-sectional dimensions of the utility tunnel remain relatively fixed over a range of lengths.

The comprehensive pipe gallery construction comprises an open cut cast-in-place method, an open cut prefabrication method, a shallow buried underground cutting method, a shield method and the like, is suitable for corresponding construction environments, and has the advantages and the disadvantages. And among the above-mentioned technical scheme, wherein, the foundation ditch is the position that the piping lane was put and is fixed, and especially the piping lane degree of depth exceeds 4m, belongs to the danger engineering, and there are safety risks such as foundation ditch collapse, eminence fall, object strike, mechanical injury in the excavation supporting process, therefore excavation and supporting of foundation ditch handle in the work progress especially important. In addition, the construction of the cast-in-place comprehensive pipe gallery structure adopts wood formworks and full supports to carry out sectional erection and dismantling, the circular construction is propelled section by section or is propelled in a jumping section, a formwork system is repeatedly erected and dismantled, the construction period of each section is long, and the consumption of manpower and turnover materials is large.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a construction process of an underground comprehensive pipe gallery, which has the characteristics of good construction quality, time and labor saving, construction cost reduction and good waterproof effect.

The purpose of the invention is realized as follows: a construction process of an underground comprehensive pipe gallery comprises the following procedures: excavating a foundation pit, constructing a main structure of a pipe gallery and constructing a road surface;

when the foundation pit excavation process is carried out, the method comprises the following steps: strengthening the pit bottom, supporting the foundation pit, dewatering the foundation pit and excavating the foundation pit;

when the pit bottom reinforcing step is carried out, reinforcing the pit bottom by adopting a cement mixing pile and a PHC tubular pile;

when the foundation pit supporting step is carried out, steel sheet piles, steel enclosing purlins and horizontal supporting supports are adopted; when the excavation depth of the foundation pit is 5.5-6.7 m, two steel purlins and horizontal supports are adopted for reinforcement; when the excavation depth of the foundation pit is 4.7-5.3 m, reinforcing by adopting a steel purlin and a horizontal support;

the step of supporting the foundation pit comprises the following procedures:

(1) measuring and paying off, utilizing a site control point to pay out the position of the steel sheet pile according to the requirement of a drawing, and longitudinally utilizing a gray line to mark as a piling direction line;

(2) digging a guide groove, digging a groove with the width of 0.5m and the depth of 0.3m outside the line of the piling direction, and leading out positioning lines at two ends of the groove by using wooden piles;

(3) the steel sheet piles are arranged in a driving mode, a single driving method is adopted when the steel sheet piles are arranged in a driving mode, namely a single steel sheet pile is clamped and lifted to the position above the driving direction line by a crawler crane, two auxiliary tools assist a pile driver to determine the position and the direction, the steel sheet piles are sunk by the self weight of the steel sheet piles when pile sinking is started, the steel sheet piles are sunk by vibration after pile bodies are stable, and the height of the steel sheet piles is 0.5m higher than the ground; controlling the verticality of the steel sheet pile by using a plumb bob when the steel sheet pile is inserted into a soil body for 4-5 m; controlling the pile top elevation of the first steel sheet pile by using a level gauge, and rechecking the pile top elevation by using the level gauge every 10m according to the top elevation of the preceding steel sheet pile by using the top elevation of the subsequent steel sheet pile; temporarily welding the previous steel sheet pile and the previous steel sheet pile by using a steel bar before the subsequent steel sheet pile is driven; when a second steel sheet pile is driven, the seam allowance is clamped with the first steel sheet pile, and then sinking is started;

(4) excavating a surface soil body, and excavating the surface soil of the foundation pit by using an excavator after the construction of the steel sheet pile is finished, wherein the excavation depth is 80 cm;

(5) constructing a steel enclosing purlin and a horizontal support by adopting an open-cut down-to-down method, wherein the central elevations of the steel enclosing purlin and the horizontal support are 80cm below the ground surface, the steel enclosing purlin is made of double-spliced H-shaped steel, and the steel enclosing purlin and a steel sheet pile are installed and fixed by welding; the horizontal supports are made of steel pipes, the longitudinal distance is 3.5m, hoisting and positioning are carried out by using a crane, the horizontal supports and the steel purlins are fixed by welding, and reinforcing plates are welded on the steel purlins at the acting positions of the horizontal supports locally;

when the foundation pit dewatering step is carried out, dewatering is carried out in the foundation pit by adopting a dewatering well, and the underground water is kept 0.5m below the excavation surface; a pit top drainage ditch with the diameter of 300mm multiplied by 300mm is dug at the top of the foundation pit, the distance from the pit top drainage ditch to the edge of the foundation pit is not less than 1m, and a water collecting well with the diameter of 800mm and the depth of 800mm is arranged in the pit top drainage ditch at the interval of 400 mm;

when the step of excavating the foundation pit is carried out, then a long-arm excavator is combined with a small excavator to carry out earthwork excavation, local manual cooperation is carried out, and the excavating and outward transportation are carried out by utilizing a slag car; the earthwork of the foundation pit needs to be excavated in a segmented and layered balanced manner, the excavation height of each layer is not more than 2m, and the excavation height of each layer of the sludge layer is not more than 1 m; a soil layer with the thickness of 200 mm-300 mm is left from the bottom of the pit and is manually dug and leveled;

excavating the foundation pit according to construction sections, wherein the length of each construction section is based on the distance between deformation joints of the main structure of the pipe gallery, namely the length of one deformation section, and the length of each construction section is 3 times or 5 times that of the deformation section; temporarily blocking adjacent construction sections in the foundation pit by adopting steel sheet piles; reserving a certain safety distance between the two ends of each construction section and the two ends of the main structure of the pipe gallery located in the construction section in a one-to-one correspondence manner; after the foundation pit of each construction section is excavated and formed, detecting a cement mixing pile and a PHC (prestressed high-strength concrete) tubular pile which are positioned in the construction section, and then constructing a cushion layer in the construction section; when the cushion layer is constructed, channel steel is used as a side template, concrete is vibrated by an inserted vibrator, the surface is leveled by a scraping bar, and the surface is polished;

when the construction process of the main structure of the pipe gallery is carried out, a skip method is adopted, namely the main structure of the pipe gallery in each construction section is numbered according to the front and back sequence of the deformation sections, then the construction of the main structure of the deformation section pipe gallery with the odd number is carried out, and the construction of the main structure of the deformation section pipe gallery with the even number is synchronously pushed after a certain time lag;

when carrying out every deformation section piping lane major structure construction, including following step: binding bottom plate reinforcing steel bars, erecting a bottom plate template, pouring bottom plate concrete, binding side walls and top plate reinforcing steel bars, erecting side walls and top plate templates, pouring side walls and top plate concrete, demolded concrete maintenance, waterproof engineering and backfilling foundation pits;

adopting a layered construction process when the steps of binding the reinforcing steel bars of the bottom plate and binding the reinforcing steel bars of the side wall and the top plate are carried out; the vertical reinforcing steel bars of the partition wall are bound at one time, the vertical reinforcing steel bars on the inner side of the side wall are also bound at one time, and the vertical reinforcing steel bars on the outer side of the side wall are welded and connected and formed twice; the binding of the length direction of the steel bars adopts lap joints, the lap joint length is 30 times of the diameter of the steel bars, the joints are staggered, the center distance of the joints is 1.3 times of the diameter of the steel bars, and the number of the joints of the steel bars on each section is not more than 25% of the total weight of the steel bars;

when the bottom plate formwork erection and the side wall and top plate formwork erection steps are carried out, the panel of the formwork adopts a bamboo plywood with the thickness of 15 mm; the vertical small longitudinal ribs adopt 50mm multiplied by 50mm wood purlin with the spacing of 200 mm; two steel pipes with the diameter of 48 mm multiplied by 3.6mm are used as upright columns in the horizontal direction, the distance is 500mm, two M14 counter-pull screw rods are used, the vertical distance is 450mm, and the upright columns are connected through bowknots; the inner core adopts a full framing scaffold and a combined wooden template, the distance between steel pipe vertical rods of the full framing scaffold is 900mm multiplied by 900mm, the top of the full framing scaffold adopts jackscrews and No. 12 channel steel to be contacted with the wooden template, the transverse distance is 900mm, and meanwhile, steel pipe cross braces are arranged;

when bottom plate concrete pouring and side wall and top plate concrete pouring steps are carried out, a cement discharging method is pushed along an axis during concrete pouring, a horizontal layering method is adopted for the side wall and the partition wall, and the layering thickness is not more than 30 cm; when the concrete is poured from a high place, the free pouring height is not higher than 2 m; adopting an insertion vibrator to vibrate, adopting a vibrating rod with the diameter of phi 50mm, wherein the vibrating distance is 300mm, the continuous vibrating time is 15-20 s, and the degree that cement paste and concrete are not settled on the surface of the concrete is taken as the standard; the plug-in vibrator is vertically inserted into concrete, the lower layer of concrete is inserted into the concrete for not less than 5cm during layered vibration, the plug-in vibrator is quickly inserted and slowly pulled out, and bubbles are gradually taken out by pumping up and down; the distance between the vibrator and the template is 8-10 cm, but is not more than 1/2 of the effective radius of the vibrator; after concrete is poured to the top surface, surface floating slurry is scraped, and a construction process of secondary vibration and secondary plastering is adopted;

the concrete layered joint part treatment measures are as follows: chiseling to expose stones without loosening, cleaning the stones, longitudinally arranging a steel plate waterstop and a concrete interface agent in the middle of a concrete layered joint, washing the concrete with high-pressure water before pouring, watering the concrete for 24 hours in advance to moisten the concrete, and spraying high-grade cement mortar on the surface layer of the old concrete, wherein the thickness of the cement mortar is 10-30 mm;

repairing concrete surface bubbles and honeycomb pitted surface: mixing cement slurry with 108 glue, filling and smearing air bubbles on the surface of the concrete after uniformly stirring, then brushing with dry cement, finally grinding with sand paper until the color of the air bubbles is consistent with that of the surrounding concrete, and finally pasting adhesive tapes on repaired parts for sealing and maintaining for 14 days and then dismantling;

when the step of formwork removal and concrete curing is carried out, the concrete joint construction joints are covered by the top surfaces of the pipe galleries through watering for moisture preservation and curing, and the curing period is not less than 14 days; maintaining the interior of the pipe gallery by adopting spraying maintenance liquid and performing watering and humidity maintenance; in summer construction, the concrete is covered with geotextile in time for moist maintenance; in high-temperature weather, a low-temperature flowing water moist curing method is adopted;

when the waterproof engineering step is carried out, the main structure is waterproof, the construction joint is waterproof, and the deformation joint is waterproof;

the main structure waterproof structure comprises a bottom plate waterproof structure, a side wall waterproof structure and a top plate waterproof structure; a waterproof layer of a bottom plate: the waterproof concrete floor is sequentially provided with a C40 waterproof concrete bottom plate, a macromolecular self-adhesive film waterproof coiled material with the thickness of 1.2mm and a C20 plain concrete cushion layer with the thickness of 200mm from inside to outside; the side wall waterproof layer is: the waterproof concrete wall of C40, the waterproof roll of the macromolecule self-adhesive film with the thickness of 1.5mm, the polystyrene foam board with the thickness of 20mm and the backfill soil are arranged from inside to outside in sequence; the waterproof layer of the top plate is as follows: sequentially arranging a C40 waterproof concrete top plate, a macromolecular self-adhesive film waterproof coiled material with the thickness of 1.5mm, a root-puncture-resistant macromolecular composite waterproof coiled material with the thickness of 1.2mm, a linoleum isolating layer and a C20 fine stone concrete protective layer with the thickness of 70mm from inside to outside;

the laying method of the waterproof roll comprises the following steps: the waterproof coiled materials at the positions 30cm above the bottom plate and the chamfer angle are constructed by a pre-paving and anti-sticking method, and the waterproof coiled materials at the side wall and the waterproof coiled materials at the top plate are constructed by a wet-paving method;

the pre-laying reverse adhesion method comprises the following steps: firstly, paving and sticking the bonding surface of the waterproof coiled material upwards, then directly pouring structural concrete on the bonding surface of the waterproof coiled material, and after the concrete is solidified, generating adhesion between the waterproof coiled material and the structural concrete;

the wet paving method comprises the following steps: c40 waterproof concrete of side wall and roof is poured and is accomplished and reach 28 days intensity after, at first scribble the grout mixture on roof and side wall, lay waterproofing membrane again, waterproofing membrane's the laying sequence is: firstly, top plate and then side wall; the formula of the cement slurry mixture is as follows: gelatin powder: cement: water: 1: 16.7: 8.35; the coating thickness of the cement slurry mixture is 2-4 mm; the smearing width of the cement paste mixture is 100-300 mmm wider than the length and the width of the waterproof coiled material respectively;

the waterproof method of the construction joint comprises the following steps: fully chiseling a joint of new and old concrete by using an electric drill or an air pick, brushing off fine stone sand by using a steel brush and cleaning a structure, then spraying water on the cleaned section to wet, coating a cement-based permeable crystalline coating, controlling the coating or coating twice according to 1.5kg per square meter, arranging a water stop steel plate in the middle of the horizontal construction joint, and coating a single-component polyurethane slow-expansion type sealant close to the water stop steel plate;

the deformation joint waterproof method comprises the following steps: embedding a steel-edged rubber water stop in the middle of the deformation joint, arranging butyronitrile cork rubber plates on two sides of the steel-edged rubber water stop in the deformation joint respectively, and installing the middle-embedded steel-edged rubber water stop at the top plate and the bottom plate of the deformation joint in a basin-type manner; caulking grooves are reserved on the upstream surface of the deformation joint top plate, the upstream surface of the deformation joint side wall and the upstream surface of the deformation joint bottom plate, and low-modulus polyurethane sealant is filled in the caulking grooves; the water receiving boxes are arranged on the back water surface at the deformation joint top plate and the back water surface at the deformation joint side wall; the upstream surface at the deformation joint bottom plate and the upstream surface at the deformation joint side wall are both provided with an externally attached rubber waterstop;

when the step of backfilling the foundation pit is carried out, backfilling soil is sand or clay, the backfilling soil is compacted in a layered mode, the backfilling is carried out uniformly and symmetrically, the thickness of each layer of backfilling layers on two sides of the pipe gallery is not larger than 250mm, and a small-sized hand-operated road roller is used for compacting; manually matching machines to tamp the top of the pipe gallery top plate in a layering mode within the range of 1000mm, wherein the backfilling thickness of each layer is not more than 250mm, a 15t non-vibration press machine is used for compacting, and the compacting coefficient is larger than 0.94; timely pulling out the steel sheet pile after the foundation pit is backfilled;

when the pavement construction process is carried out, the method comprises the following steps: constructing a gravel cushion layer, a water stabilization layer and an asphalt surface layer;

the construction step of the gravel cushion comprises the following procedures: wetting the lower bearing layer by sprinkling water, filling, paving, leveling, rolling and maintaining;

the water stabilization layer construction step comprises the following procedures: sprinkling water to wet the lower bearing layer, filling, spreading and rolling;

the asphalt surface layer construction step comprises the following procedures: spraying adhesive layer oil and asphalt mixture, spreading and rolling.

The construction process of the underground comprehensive pipe gallery comprises the following steps of carrying out the foundation pit backfilling step of the pipe gallery main body construction process:

the mechanical flow operation of digging, loading, transporting, spreading, leveling and pressing is adopted for filling soil and filling earthwork. Converting the spreading area of each earthwork according to the average volume of the soil on the self-discharging automobile, scattering a network line by lime, arranging a specially-assigned person on site to command the earthwork allocation, and discharging 1 earthwork per grid;

spreading, firstly, carrying out primary leveling by using a bulldozer, carrying out static pressure twice by using a road roller so as to expose potential unevenness and manually filling a local uneven place, after finishing spreading, extracting a cross section, measuring by using a level gauge to calculate the thickness of the spread soil, checking the error between the spreading and the planned spreading thickness, and providing a basis for calculating a compaction coefficient;

and thirdly, rolling by using a road roller, and adopting a longitudinal advancing and retreating type rolling mode, wherein the driving speed of the road roller is firstly slow and then fast and does not exceed 2km/h, the vibration is firstly light and then heavy during rolling and is changed from weak vibration to strong vibration, transverse joints are overlapped by 0.4-0.5 m during rolling, the longitudinal overlapping of two adjacent sections in the front and the back is not less than 2.0m, the stagger of filling joints in the upper and the lower layers is not less than 2m, longitudinal wheel tracks are overlapped by 1/3-1/2 wheel widths and are not less than 30cm, and corners are compacted by small-sized compacting equipment.

The construction process of the underground comprehensive pipe gallery is characterized in that when the waterproof engineering step of the pipe gallery main body construction process is carried out, the grooving mode of the caulking groove is as follows: pre-burying a metal or hardwood strip which is in a withdrawing shape and coated with a release agent on the surface at a design position before pouring concrete, and pulling out the metal or hardwood strip to form a groove when the concrete is initially set;

the method for externally attaching the water stop at the deformation joint bottom plate comprises the following steps: arranging a wood template at the deformation joint, wherein the width of the wood template is 60cm, fixing the wood template on a steel plate, ensuring that the surface of the wood template is flush with the upstream surface of the deformation joint bottom plate, and then attaching an externally attached rubber water stop belt on the wood template;

the method for manufacturing the externally-attached water stop at the deformation joint side wall comprises the following steps: and after the steel mould is installed, attaching the externally-attached rubber waterstop to the steel mould plate corresponding to the deformation joint, and then pouring the side wall concrete.

In the construction process of the underground comprehensive pipe gallery, when the rolling process of the broken stone cushion layer construction step of the pavement construction process is carried out, a vibratory roller with the length of more than 12t is adopted, and the straight line and the flat curve section without the super high are rolled from the road shoulders on the two sides to the road center; rolling the section with the ultrahigh flat curve from the inner side road shoulder to the outer side road shoulder; when rolling, overlapping 1/2 wheel widths on the rear wheel of the road roller, and rolling for 6-8 times for each section;

when the rolling process of the water stabilization layer construction step is carried out, a three-wheel roller, a vibratory roller or a tire roller with the thickness of more than 15t is adopted, static pressure is adopted for 1-2 times during rolling, manual leveling is adopted if a certain uneven place exists on the surface of the stabilization layer after static pressure, and then vibration rolling is carried out; the rolling route is that the straight line section is rolled from the two sides to the middle of the road surface, and the ultra-high section is rolled from the inner side to the outer side of the road surface;

when the rolling process of the asphalt surface layer construction step is carried out, primary pressing, secondary pressing and final pressing are adopted;

A. initial pressing: rolling for two times by using a self-weight light steel wheel road roller; the sequence of initial pressure: the road roller is pressed to the road center from one side of the road shoulder or rolled from a low side to a high side; the rear wheels are overlapped for 1/3-1/2 wheel widths, 20-30 cm is reserved near the kerbstone and compacted by a small vibration roller or a vibration tamping plate; static pressure during forward movement and vibration pressure during backward movement are adopted as initial pressure, and low-amplitude high-frequency is adopted by the road roller;

B. repressing: rolling by adopting two tire rollers, wherein the tire pressure is not less than 0.7Mpa, the rear wheels of the road roller are overlapped for 1/3-1/2 wheel widths, the temperature of the asphalt mixture is not lower than 120-135 ℃, the re-pressing sequence is the same as the initial pressing, the re-pressing times are 6-8 times, and the re-pressing speed is 4 km/h;

C. final pressure: the wide-width double-steel-wheel vibratory roller is adopted, the temperature of the asphalt mixture is above 90 ℃, the number of times of final pressing is 2, the final pressing speed is 2.5-3.54 km/h, the sequence of the final pressing is the same as that of the initial pressing, and the temperature of the asphalt mixture after the rolling is finished is not lower than 65-80 ℃.

The construction process of the underground comprehensive pipe gallery has the following characteristics: when carrying out piping lane major structure construction, adopt the method of jumping the storehouse to be under construction, can not only solve the fracture problem of bulky concrete, can also the continuity of full play construction and the configuration quantity that reduces the workman. The construction process has the characteristics of good construction quality, high construction efficiency, high safety, time and labor saving, construction cost reduction and good waterproof effect.

Detailed Description

The present invention is further described below.

The invention relates to a construction process of an underground comprehensive pipe gallery, which comprises the following procedures: excavating a foundation pit, constructing a main structure of a pipe gallery and constructing a road surface;

the construction of the cement mixing pile comprises the following procedures:

(1) before construction, the ground is leveled, and the above-ground and underground obstacles are removed completely, so that the pile machine foundation is level, solid, stable and applicable;

(2) positioning and centering: moving the deep layer stirrer to reach the designated pile position and centering, wherein the centering error is not more than 2cm, and adjusting the verticality and the levelness of the deep layer stirrer by using a plumb bob and a horizontal ruler arranged on the stirrer to ensure that a drill rod of the stirrer keeps vertical; the perpendicularity error should not exceed 0.3% L;

(3) pre-stirring and sinking: after the cooling water circulation of the deep layer stirring machine is normal, starting the deep layer stirring machine to enable the deep layer stirring machine to stir and sink along the guide frame, controlling the sinking speed of the deep layer stirring machine, and if the sinking speed is too slow, supplying clear water from the slurry conveying system to facilitate drilling;

(4) preparing cement paste: while the deep layer stirrer is used for pre-stirring and sinking, the background is used for stirring cement slurry according to the design determined mixing ratio, the stirring pile adopts 42.5R ordinary portland cement, the mixing amount is more than or equal to 13 percent, the water cement ratio is 0.5-0.6, the mixing time is not less than 3min after each feeding, and the slurry is poured into a collecting hopper before grouting;

(5) spraying, stirring and lifting: after the deep layer stirring machine sinks to the designed depth, starting an mortar pump, and lifting the deep layer stirring machine while spraying the mortar strictly according to the lifting speed determined by the design when the mortar reaches a mortar spraying opening;

(6) and (3) repeatedly stirring: when the deep layer stirring machine sprays slurry and is lifted to the designed top surface elevation, the mortar pump is closed, the slurry in the collecting hopper is just emptied, and in order to ensure that the soft soil and the slurry are uniformly stirred, the deep layer stirring machine is stirred and sunk again, and the stirring is lifted to the designed slurry stopping surface;

(7) cleaning machines and pipelines: injecting a proper amount of clear water into the collecting hopper, starting a mortar pump, cleaning residual cement paste in all pipelines until the cement paste is basically clean, and cleaning the soft soil adhered to the stirring head;

(8) and (3) shifting: and (5) repeating the steps (2) to (7) according to the designed reinforcement range and the pile position to construct the next pile.

When the step of supporting the foundation pit is carried out, steel sheet piles, steel enclosing purlins and horizontal supporting supports are adopted; the driving bottom elevation of the steel sheet pile is-9.5 m, and the driving width of the steel sheet pile is the width of the pipe gallery and the extension of each side of the pipe gallery is 1.5 m; when the excavation depth of the foundation pit is 5.5-6.7 m, two steel purlins and horizontal supports are adopted for reinforcement; when the excavation depth of the foundation pit is 4.7-5.3 m, reinforcing by adopting a steel purlin and a horizontal support;

the step of supporting the foundation pit comprises the following procedures:

(3) the steel sheet pile is driven, a screen type driving method is adopted when the steel sheet pile is driven, namely, a single steel sheet pile is clamped and lifted to the upper space of a pile driving direction line by using a crawler crane, two auxiliary tools use a tool to assist a pile driver to determine the position and the direction, the steel sheet pile is firstly sunk by using the self weight of the steel sheet pile when pile sinking is started, the steel sheet pile is vibrated and sunk after a pile body is stabilized, and the height of the steel sheet pile is 0.5m higher than the ground; controlling the verticality of the steel sheet pile by using a plumb bob when the steel sheet pile is inserted into a soil body for 4-5 m; controlling the pile top elevation of the first steel sheet pile by using a level gauge, and rechecking the pile top elevation by using the level gauge every 10m according to the top elevation of the preceding steel sheet pile by using the top elevation of the subsequent steel sheet pile; temporarily welding the previous steel sheet pile and the previous steel sheet pile by using a steel bar before the subsequent steel sheet pile is driven; when a second steel sheet pile is driven, the seam allowance is clamped with the first steel sheet pile, and then sinking is started;

(4) excavating a surface soil body, and excavating the surface soil of the foundation pit by using an excavator after the construction of the steel sheet pile is finished, wherein the excavation depth is 150 cm;

(5) constructing a steel enclosing purlin and a horizontal support by adopting an open-cut down-to-down method, wherein the central elevations of the steel enclosing purlin and the horizontal support are 80cm below the ground surface, the steel enclosing purlin is made of double-spliced H-shaped steel, and the steel enclosing purlin and a steel sheet pile are installed and fixed by welding; the horizontal supports are made of steel pipes, the longitudinal distance is 3.5m, hoisting and positioning are carried out by using a crane, the horizontal supports and the steel purlins are fixed by welding, and reinforcing plates are welded on the steel purlins at the acting positions of the horizontal supports locally.

When the foundation pit dewatering step is carried out, dewatering is carried out in the foundation pit by adopting a dewatering well, and the underground water is kept 0.5m below the excavation surface; a pit top drainage ditch with the size of 300mm multiplied by 300mm is dug at the top of the foundation pit, the distance from the pit top drainage ditch to the edge of the foundation pit is not less than 1m, and a water collecting well with the diameter of 800mm and the depth of 800mm is arranged in the pit top drainage ditch at the interval of 400 mm.

When the step of excavating the foundation pit is carried out, then a long-arm excavator is combined with a small excavator to carry out earthwork excavation, local manual cooperation is carried out, and the excavating and outward transportation are carried out by utilizing a slag car; the earthwork of the foundation pit needs to be excavated in a segmented and layered balanced manner, the length of each segment is 6m, the excavation height of each layer is not more than 2m, and the excavation height of each layer of the sludge layer is not more than 1 m; the slope of the temporary slope at two sides of the foundation pit is not less than 1:2, and the height difference is less than 1 m; a soil layer with the thickness of 200 mm-300 mm is left from the pit bottom and is manually dug and leveled, so that the disturbance of the pit bottom soil is prevented;

excavating the foundation pit according to construction sections, wherein the length of each construction section is based on the distance between deformation joints of the main structure of the pipe gallery, namely the length of one deformation section, and the length of each construction section is 3 times or 5 times of the length of the deformation section according to the length of a reinforcing section of the on-site cement mixing pile and the condition of personnel organization; temporarily blocking adjacent construction sections in the foundation pit by adopting steel sheet piles; a certain safety distance is reserved between the two ends of each construction section and the two ends of the main structure of the pipe gallery located in the construction section in a one-to-one correspondence manner, so that the construction of the main structure of the pipe gallery is facilitated; after the foundation pit of each construction section is excavated and formed, detecting a cement mixing pile and a PHC (prestressed high-strength concrete) tubular pile which are positioned in the construction section, and then constructing a cushion layer in the construction section; when the cushion layer is constructed, No. 10 channel steel is used as a side template, concrete is vibrated by an inserted vibrator, the surface is leveled by a scraping bar, and the surface is polished and polished;

during the construction process of the main structure of the pipe gallery, the construction is carried out by adopting a skip method, namely, the main structure of the pipe gallery in each construction section is numbered according to the front and back sequence of the deformation sections, then the construction of the main structure of the pipe gallery with the deformation sections numbered as 1, 3 or 1, 3 and 5 is carried out, and the construction of the main structure of the pipe gallery with the deformation sections numbered as 2 or 2 and 4 is synchronously pushed after a certain time lag;

repairing concrete surface bubbles and honeycomb pitted surface: mixing cement slurry with 108 kinds of glue, stirring, filling and smearing air bubbles on the surface of the concrete, painting with dry cement, finally grinding with sand paper until the color of the air bubbles is consistent with that of the surrounding concrete, and finally adhering adhesive tapes to the repaired parts for sealing and curing for 14 days and then dismantling.

When the step of formwork removal and concrete curing is carried out, the concrete joint construction joints are covered by the top surfaces of the pipe galleries through watering for moisture preservation and curing, and the curing period is not less than 14 days; maintaining the interior of the pipe gallery by adopting spraying maintenance liquid and performing watering and humidity maintenance; in summer construction, the concrete is covered with geotextile in time for moist maintenance; in high temperature weather, a low-temperature flowing water moist curing method is adopted.

the waterproof method of the construction joint comprises the following steps: fully chiseling a joint of new and old concrete by using an electric drill or an air pick, brushing off fine stone sand by using a steel brush and cleaning a structure, then spraying water on the cleaned section and wetting, coating a cement-based permeable crystalline coating, controlling the coating or coating twice according to 1.5kg per square meter, arranging a water stop steel plate in the middle of the construction joint, and coating a single-component polyurethane slow-expansion type sealant close to the water stop steel plate; the water stop steel plate is manufactured into a dovetail shape, namely, the two sides of the steel plate strip with the width of 50mm are bent for 45 degrees to form dovetails, and the lengths of the dovetails are respectively 50 mm; dovetail on two sides of the water-stopping steel plate at the bottom plate and the top plate face upwards, and dovetail on two sides of the water-stopping steel plate at the side wall faces outwards; the water stop steel plates at the corner positions of the horizontal and vertical construction joints of the bottom plate and the side walls are bent into arcs, and the radius of the water stop steel plates is larger than 200 mm;

the mounting mode of the water stop steel plates at the bottom plate, the top plate and the side wall is as follows: firstly, arranging two positioning ribs with the diameter of phi 12mm at 1/2 parts of the structure thickness at intervals of 30cm, wherein the length of each positioning rib is 50cm, welding dovetails on two sides of a water stop steel plate with the two positioning ribs in a one-to-one correspondence manner, and then pouring concrete;

the construction method of the cross position of the longitudinal and transverse water stop steel plates comprises the following steps: two side dovetails for stopping water of the steel plates are cancelled, two crossed water stopping steel plates are lapped, the lapping length is 5mm, and then the periphery of the steel plates is fully welded;

the deformation joint waterproof method comprises the following steps: steel-edged rubber water stops are embedded in the middle of the deformation joint, the two sides of the embedded steel-edged rubber water stops in the deformation joint are respectively provided with a butyronitrile cork rubber plate, and the embedded steel-edged rubber water stops at the deformation joint top plate and the deformation joint bottom plate are installed in a basin mode; caulking grooves are reserved on the upstream surface of the deformation joint top plate, the upstream surface of the deformation joint side wall and the upstream surface of the deformation joint bottom plate, and low-modulus polyurethane sealant is filled in the caulking grooves; the water receiving boxes are arranged on the back water surface at the deformation joint top plate and the back water surface at the deformation joint side wall; and the upstream surface at the deformation joint bottom plate and the upstream surface at the deformation joint side wall are both provided with an externally attached rubber waterstop.

The grooving mode of the caulking groove is as follows: before concrete is poured, metal or hardwood strips which are in a withdrawing shape and coated with a release agent on the surface are pre-buried at a design position, and the metal or hardwood strips are pulled out to form grooves when the concrete is initially set.

The method for externally attaching the water stop at the deformation joint bottom plate comprises the following steps: the wood formwork is arranged at the deformation joint, the width of the wood formwork is 60cm, the wood formwork is fixed on the steel plate, the surface of the wood formwork is enabled to be flush with the upstream surface of the deformation joint bottom plate, and then the externally-attached rubber water stop band is attached to the wood formwork.

When the step of backfilling the foundation pit is carried out, backfilling soil is sand or clay, the backfilling soil is compacted in a layered mode, the backfilling is carried out uniformly and symmetrically, the thickness of each layer of backfilling layers on two sides of the pipe gallery is not larger than 250mm, and a small-sized hand-operated road roller is used for compacting; manually matching machines to tamp the top of the pipe gallery top plate in a layering mode within the range of 1000mm, wherein the backfilling thickness of each layer is not more than 250mm, a 15t non-vibration press machine is used for compacting, and the compacting coefficient is larger than 0.94; timely pulling out the steel sheet pile after the foundation pit is backfilled; the foundation pit backfilling is carried out according to the following requirements:

and thirdly, rolling by using a road roller, and adopting a longitudinal advancing and retreating type rolling mode, wherein the running speed of the road roller is slow firstly and then fast, and does not exceed 2km/h, the vibration is light firstly and then heavy during rolling, the vibration is changed from weak vibration to strong vibration, transverse joints are overlapped by 0.4-0.5 m during rolling, the longitudinal overlapping of two adjacent sections at the front and the back is not less than 2.0m, the staggering of filling joints at the upper layer and the lower layer is not less than 2m, longitudinal wheel tracks are overlapped by 1/3-1/2 wheel widths, and the wheel widths are not less than 30cm, the rolling is uniform, corners are compacted by using small-sized compacting equipment, and no pressure leakage and dead angle are realized.

the construction step of the gravel cushion comprises the following procedures: wetting the lower bearing layer by sprinkling water, filling, paving, leveling, rolling and maintaining; rolling with a vibratory roller with the weight of more than 12t, wherein straight line and non-super-high flat curve sections are rolled from the road shoulders on two sides to the center of the road, and the super-high flat curve sections are rolled from the road shoulder on the inner side to the road shoulder on the outer side; when rolling, overlapping 1/2 wheel widths on the rear wheel of the road roller, and rolling for 6-8 times for each section;

the water stabilization layer construction step comprises the following procedures: sprinkling water to wet the lower bearing layer, filling, spreading and rolling; rolling by using a three-wheel roller, a vibratory roller or a tire roller of more than 15t, starting 1-2 times of rolling by using static pressure, manually leveling if a certain uneven place exists on the surface of a stable layer after static pressure, and then performing vibratory rolling; the rolling route is that the straight line section is rolled from the two sides to the middle of the road surface, and the ultra-high section is rolled from the inner side to the outer side of the road surface;

the asphalt surface layer construction step comprises the following procedures: spraying adhesive layer oil, paving and rolling the asphalt mixture, and adopting initial pressing, re-pressing and final pressing;

The above embodiments are provided only for illustrating the present invention and not for limiting the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and therefore all equivalent technical solutions should also fall within the scope of the present invention, and should be defined by the claims.

Claims

1. The construction process of the underground comprehensive pipe gallery is characterized by comprising the following procedures: excavating a foundation pit, constructing a main structure of a pipe gallery and constructing a road surface;

the step of supporting the foundation pit comprises the following procedures:

2. The underground pipe gallery construction process according to claim 1, wherein the step of backfilling the foundation pit in the pipe gallery main body construction process is carried out according to the following requirements:

3. The underground pipe gallery construction process according to claim 1, wherein when the waterproof engineering step of the pipe gallery main body construction process is performed, the grooving mode of the caulking groove is as follows: pre-burying a metal or hardwood strip which is in a withdrawing shape and coated with a release agent on the surface at a design position before pouring concrete, and pulling out the metal or hardwood strip to form a groove when the concrete is initially set;

4. The construction process of the underground comprehensive pipe gallery according to claim 1, wherein when the rolling process of the broken stone cushion layer construction step of the pavement construction flow is carried out, a vibratory roller with the length of more than 12t is adopted, and straight lines and flat curve sections without superelevation are rolled from road shoulders on two sides to the center of the road; rolling the section with the ultrahigh flat curve from the inner side road shoulder to the outer side road shoulder; when rolling, overlapping 1/2 wheel widths on the rear wheel of the road roller, and rolling for 6-8 times for each section;