CN111893827A

CN111893827A - Construction process of urban trunk road

Info

Publication number: CN111893827A
Application number: CN202010777649.XA
Authority: CN
Inventors: 曹凯飞; 许海波; 胡德智; 陈鹏; 王杰; 蒋永辉; 张亮
Original assignee: CCCC Shanghai Dredging Co Ltd.
Current assignee: CCCC Shanghai Dredging Co Ltd.
Priority date: 2020-08-05
Filing date: 2020-08-05
Publication date: 2020-11-06

Abstract

The invention discloses a construction process of an urban trunk road, which comprises the following steps: construction preparation, roadbed excavation, roadbed filling, embankment side slope protection and pavement construction; the construction preparation flow comprises the following steps: determining a field working boundary line, measuring and lofting and cleaning a field; the roadbed excavation process comprises the following steps: excavating a substrate, trimming a foundation bed slope and compacting a roadbed; the roadbed filling process comprises the following steps: measuring and lofting, treating a substrate, filling and rolling, filling and digging a joint construction and draining a filling section; performing a embankment side slope protection process, and adopting grass planting protection when the height H of the embankment side slope is less than or equal to 3 m; when the height H of the embankment side slope is more than 3m, adopting a mortar rubble framework for protection; solid slope protection is adopted for the filling pond section; the pavement construction process comprises the following steps: paving a graded broken stone cushion layer, constructing a cement stabilized broken stone base layer and constructing an asphalt concrete surface layer. The construction process can improve the overall stability of the pavement and avoid uneven settlement.

Description

Construction process of urban trunk road

Technical Field

The invention relates to a construction process of an urban trunk road.

Background

The city main road construction is a civil actual project, can comprehensively improve the city quality, further perfects the city infrastructure construction, improves the city appearance, and has important significance for building beautiful, neat, civilized, beautiful and normative and ordered city environment and continuously enhancing the acquaintance and the happiness of citizens. However, with the increasing mileage of highway construction, the quality problem of road construction is becoming a focus. For example, the road surface is difficult to pave and compact due to the overlarge internal porosity and the overlarge water permeability coefficient of the material; once the highway is put into use, the quality problems of cracks, potholes and the like are easy to occur on the road surface in high-temperature rainy seasons after traffic is on.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a construction process of an urban trunk road, which can improve the overall stability and smoothness of the road surface, avoid uneven settlement and improve the driving comfort of road vehicles.

One technical scheme for achieving the purpose of the invention is as follows: a construction process of an urban trunk road comprises the following steps: construction preparation, roadbed excavation, roadbed filling, embankment side slope protection and pavement construction;

the construction preparation process comprises the following steps: determining a field working boundary line, measuring and lofting and cleaning a field;

the roadbed excavation process comprises the following steps: excavating a substrate, trimming a foundation bed slope and compacting a roadbed;

when the step of excavating the substrate is carried out, excavating on the gentle cross slope section of the soil cutting by adopting a transverse step; adopting layered excavation in a deep cutting section; assisting in artificial excavation close to the surface of the bottom layer of the foundation bed and the side slope; excavating from top to bottom, and transporting soil and stones by adopting an excavator in cooperation with a dump truck and a scraper;

when a foundation bed side slope trimming step is carried out, according to the measured position of the side pile, the soil cutting machine is excavated to a position which is 0.1-0.2 m close to the foundation bed side slope surface, manual slope trimming is carried out, and the slope is manually brushed by inserting rods and hanging wires every time one layer is excavated;

when the road bed compaction step is carried out, a heavy vibratory roller is adopted to longitudinally carry out along the road, static pressure is firstly carried out and then vibration pressure is carried out during rolling, the speed is slow firstly and then fast, the vibration is from weak vibration to strong vibration, and the maximum speed of the roller is not more than 4 km/h; the straight line section is longitudinally advanced and retreated from two sides to the middle, the curve section is longitudinally advanced and retreated from the inner side to the outer side, and the edge part is rolled for 2-3 times; the overlap of the transverse wheel tracks of the road roller is not less than 40cm, the overlap of the longitudinal wheel tracks of two sections adjacent to each other in front and back is not less than 2.0m, and the filling joints of the upper layer and the lower layer are staggered by 3 m;

when the roadbed filling process is carried out, the method comprises the following steps: measuring and lofting, treating a substrate, filling and rolling, filling and digging a joint construction and draining a filling section;

when the step of substrate treatment is carried out, vegetation, garbage, surface soil and impurity soil on the ground surface are removed, accumulated water is removed, and sludge is dug out; the steep slope section excavates the surface into steps, and the width meets the operation requirement of paving and compacting machinery; firstly loosening and then compacting within 0-0.3 m below the top surface of the roadbed of the zero-fill road section, and ensuring that the compactness is not less than 95%; filling the bottom filling and the zero filling excavation road bed surface on the special roadbed soil layer according to the requirement, and then normally filling the roadbed;

when the filling step is carried out, parallel operation is carried out by adopting a method of filling soil filler horizontally and hierarchically, longitudinally segmenting, paving by using a bulldozer, leveling by using a leveler and rolling by using a heavy vibrating road roller; the loose paving thickness of each layer of filling is not more than 30cm, and when the filling thickness of the top layer is less than 10cm, the lower layer of filling is turned loose to a certain depth and is rolled together with new filling; filling earth with different soil qualities in a layered manner, wherein the filling thickness of each filling earth is not less than 0.5 m;

when the step of filling and rolling is carried out, the filling is roughly leveled by a bulldozer, then the leveling is finely leveled by a leveler, and rolling is carried out after the leveling degree after the fine leveling is controlled to be less than 3 cm; rolling for 2 times by using a vibratory roller with 15t, and then rolling by using a vibratory roller with the vibration force of more than 30t until the specified compaction degree is reached, and controlling the rolling width of the roadbed to be more than 50cm larger than the designed width;

when the construction step of filling and digging the joint part is carried out, the filling and digging joint part or the ground natural transverse slope is more than 1: 5, digging the original ground into steps, wherein the width of each step is not less than 1.0 m, and the top surfaces of the steps are made into inward-inclined slopes with the gradient of 2% -4%; when filling, leveling each step and then filling the previous layer; a transition section with the length not less than 10 meters is arranged at the excavation square section at the longitudinal filling and excavating junction; when the roadbed is constructed in a segmented mode, at joints, layered filling needs to be lapped, and the step of paving the roadbed is as follows: 1, steps are left on the slope layer by layer; two sections are constructed simultaneously, and are overlapped and connected in a layered mode, and lap joints are staggered by more than 2 meters at least;

when the drainage construction step of the filling section is carried out, drainage is carried out to the outer side of the side slope according to the transverse gradient of 2 percent, in the roadbed filling process, road grooves are built immediately after each layer of filling operation surface is rolled and formed, and temporary drainage grooves are arranged on the side slope according to the distance of 20 m;

performing a embankment side slope protection process, and adopting grass planting protection when the height H of the embankment side slope is less than or equal to 3 m; when the height H of the embankment side slope is more than 3m, adopting a mortar rubble framework for protection; the filling pond section adopts solid revetments, and the slope of the solid revetments is 1: 1.5;

when the pavement construction process is carried out, the method comprises the following steps: paving a graded broken stone cushion layer, constructing a cement stabilized broken stone base layer and constructing an asphalt concrete surface layer;

when the step of paving the graded broken stone cushion layer is carried out, the method comprises the following working procedures: measuring and paying off, preparing a lower bearing layer, mixing materials, transporting, paving, rolling, detecting and maintaining;

when the material mixing process is carried out, the proportion of the sand to the stone is 38:62, the maximum particle size of the crushed stone is not more than 31.5mm, and the crushing value of the crushed stone is not more than 26%;

when the transportation and paving processes are carried out, quincunx stacking is adopted, and a paver is adopted for paving, wherein the loose paving coefficient is 1.2;

when the rolling process is carried out, static pressing is carried out once, vibration rolling is carried out for three times, and finally, smooth surface pressing is carried out once until the compactness of the broken stone cushion layer meets the standard requirement, the rolling sequence is low firstly and high secondly, light firstly and heavy secondly, static firstly and dynamic secondly, slow firstly and fast secondly, and meanwhile, the tracks of each time are overlapped 1/3;

when the construction step of the cement stabilized macadam foundation is carried out, the method comprises the following working procedures: construction preparation, lower bearing layer detection and cleaning, measurement lofting, mixing and transportation of a crushed stone mixture, paving and rolling of the crushed stone mixture, seam treatment and health maintenance;

when the measurement lofting process is carried out, the road control line at least has two sidelines and a central line; setting an elevation control section every 10m on the straight line section, and setting an elevation control section every 5m on the curve or the bent section; measuring a paving reference elevation on each elevation control section by using a level gauge, pulling out two paving reference lines, drilling a thickness control line steel pile between the two paving reference lines, calculating the loose paving thickness according to the loose paving coefficient, determining the height of a control line, and hanging a steel wire rope on the control line steel pile at the height of the control line;

when the working procedures of mixing and transporting the crushed stone mixture are carried out, the maximum particle size of stone is not more than 31.5mm, the crushing value of the crushed stone is not more than 30%, the content of organic matters is not more than 2%, and the content of sulfate is not more than 0.25%; the adopted cement is 42.5-grade ordinary portland cement or slag portland cement with initial setting time of more than 3h and final setting time of not less than 6 h; the dosage of the cement is 3 to 5.5 percent;

when the broken stone mixture is paved and rolled, a paver is adopted during paving, and the paving speed is 1.5-2 m/m in; when the working section with the paving interruption of more than 2h is finished, a seam is required to be arranged, a transverse seam is arranged perpendicular to the center line of the road, and a longitudinal seam is arranged along the direction of the center line of the road; the driving wheel faces the direction of the paver during rolling, and the road side drives the road to roll at low speed according to the principle that the road is light firstly and then heavy, static firstly and then vibrated, slow firstly and then fast, wheel tracks are overlapped, the lower part is dense firstly and then the upper part is dense; during rolling, the roller is pressed until no wheel mark exists by following the procedures of 3-4 times of initial pressing of the double steel wheels → 1-2 times of light vibration rolling → 3 times of heavy vibration rolling → 2 times of rolling of the steel wheel rolling; the wheel tracks are overlapped 1/2 wheel widths when the road roller rolls; the speed during rolling is 1.5-1.7 km/h for the first time to the second time, and the speed of each later time is 1.8-2.2 km/h;

when the joint processing procedure is carried out, marking a joint processing line at the joint position by using a gray line, chiseling the tail end of the mixture after rolling along the full width of the spreading layer before next spreading until the top surface of the lower bearing layer is chiseled, and enabling the chiseling section to be a vertical surface and to be vertical to the top surface of the lower bearing layer and the central line of the road; before spreading, spraying water on the chiseled section and manually brushing cement paste to ensure that the spreading layer of the new and old mixture at the joint is bonded; transverse pressing is adopted by the spread transverse hard joint to ensure the flatness, the transverse pressing of the joint is carried out according to the procedures of pressure stabilization and micro-vibration rolling, the coarse aggregate at the joint is removed in time after the pressure stabilization, and the joint is repaired by fine aggregate and then is vibrated and rolled; the road roller rolls transversely along the joint, gradually pushes a new mixture spreading layer from the compaction layer of the previous day, and rolls normally longitudinally after finishing rolling;

when the construction step of the asphalt concrete surface course is carried out, the method comprises the following working procedures: measuring and lofting, checking and cleaning a lower bearing layer, spraying permeable asphalt and a lower sealing layer, mixing asphalt concrete, transporting, paving asphalt concrete, rolling, processing seams, maintaining and checking.

When the measurement lofting process is carried out, firstly, the center line measurement is carried out, and then the edge position is measured according to the center line and the design width; carrying out leveling elevation measurement lofting on every 10m section of a straight line section and every 5m section of a curve or a bent section, rechecking the elevation of the cement stabilized macadam base layer, and hanging a steel wire on a steel wire support according to the elevation to be used as a datum line for paving construction;

when the prime coat asphalt and the lower seal coat are sprayed, the prime coat asphalt is sprayed on the surface of the cement stabilized macadam base layer and permeatesThe depth is not less than 5 mm; the permeable layer asphalt adopts slow-cracking sprinkling type cation emulsified asphalt, and the dosage is 0.7-1.5L/m²(ii) a When a lower seal coat is laid on the permeable asphalt, firstly, an asphalt spreading vehicle is used for spraying emulsified asphalt, the whole spreading width is kept to be uniformly sprayed in the spraying process, and the using amount is 0.9-1.3 Kg/m²(ii) a Paving the joints sprayed by the front vehicle and the rear vehicle with iron plates or building paper for 1-1.5 m; when spraying in several steps, the longitudinal lap joint width is 100-150 mm; after the emulsified asphalt is sprayed, the aggregate spreader is used for spreading the stone chips immediately, and the using amount is 5-8 m³/1000m²(ii) a At the lap joint of the two frames, the first frame is kept for a time when the emulsified asphalt is sprayed, the width of 100-150 mm is not spread with stone chips, and the second frame is spread with the stone chips; after the stone chips are spread, immediately rolling 3-4 times from the roadside to the center of the road by using a 6-8 t steel wheel road roller, wherein each layer of wheel tracks are overlapped by 300 mm; the rolling speed does not exceed 2km/h at the beginning;

when the asphalt concrete mixing process is carried out, stirring the asphalt mixture by using an intermittent stirrer for 30-50 s;

when the asphalt concrete paving procedure is carried out, two pavers are adopted to carry out step operation, and the front-rear distance between the two pavers is kept to be more than 20 m; reserving a width of 10-20 cm at the front part of the spread layer for temporary rolling to serve as a height reference surface of a new spread layer, overlapping the spread layers of 5-10 cm, and finally performing bridging seam rolling in a hot seam mode; the longitudinal seams of the upper layer and the lower layer are staggered by more than 15 cm; paving a reference surface with the length of 1m at the starting point of the connecting layer and the surface layer manually according to the paving width, multiplying the elevation of the reference surface by a loose paving coefficient according to the designed elevation, and adjusting a scale according to the paving thickness; the spreading machine retreats to the position of the reference surface, and the leveling plate is lowered to the reference surface; the paving is carried out according to a longitudinal straight line; the spreading speed is 1-2.9 m/min.

When the rolling process is carried out, immediately using a road roller to roll from the seam by static force at the rear of the paver; reserving 30cm of non-pressure when rolling the first paving belt, and rolling the adjacent belts together when rolling; rolling and segmenting, wherein the length of each segment is 30-50 m, namely, primary compression, secondary compression and final compression; when more than two road rollers work simultaneously, the front-back distance is not less than 3 m; when the vehicle runs on the ramp in a longitudinal queue, the distance between the two wheels is not less than 20 m; the width of each overlapped rolling wheel is 30cm when the double-wheel road roller rolls; 1/2 of the width of the rear wheel is overlapped each time when the three-wheel roller rolls; the rolling comprises primary rolling, secondary rolling and final rolling;

during primary rolling, lightly pressing for 2 times by using a 6-8 t steel wheel static road roller, wherein the rolling speed is 1.5-2 km/h; the rolling sequence is started from the roadside, and the road is gradually pressed into the road by low-speed slow walking; the primary grinding temperature is not lower than 130-145 ℃, and the modified asphalt is not lower than 150 ℃.

When in secondary rolling, a 10-15 t tire vibratory roller is used for heavy pressing for 4-6 times until the road surface is stable and compact, so that the road surface is formed, the rolling speed is 4-5 km/h, the overlapping width of adjacent rolling belts is 10-20 cm during rolling, the vibratory roller stops vibrating when reversing and starts vibrating after starting in the other direction; the temperature of the double grinding is not lower than 90 ℃;

during final rolling, rolling for 2-6 times by using a 6-8 t steel wheel static road roller, mainly rolling the road surface, eliminating wheel tracks generated in rolling, wherein the rolling speed is 2-3 cm; the final grinding temperature is not lower than 70 ℃;

when the seam processing procedure is carried out, the method comprises longitudinal seam processing and transverse seam processing;

when longitudinal joint processing is carried out, a thermal joint is needed when the joint of the main line and the intersection needs to be made; paving the crossroads, coating asphalt at the joint cutting positions, overlapping the main lines for 5-10 cm in width during paving, and shoveling after paving; during rolling, the road roller is positioned on the compacted road surface, the width of the road roller extending across the new paving layer is 15cm, then the new paving layer is rolled, the width of the road roller extending across the compacted road surface is 10-15 cm, and the longitudinal seams of the upper layer surface and the lower layer surface are staggered by more than 200 mm;

when longitudinal seam processing is carried out, an oblique seam is adopted, namely the seams of the upper layer and the lower layer are staggered by more than 1 m; measuring the position of the uneven cross section by using a ruler, wherein each section is not less than 4, cleaning the section during lapping, coating adhesive oil, and preheating; transversely rolling the joint, wherein a road roller is positioned on the compacted pavement and extends into the newly laid layer by 15cm during rolling, and then moving the newly laid layer by 15-20 cm after each time of rolling until all the newly laid layers are rolled, and then longitudinally rolling; when the adjacent spreading layers are formed and have longitudinal seams, a steel wheel road roller is firstly used for rolling once along the longitudinal seams, the width of the steel wheel road roller is 15-20 cm, then transverse rolling is carried out along the transverse seams, and finally normal longitudinal rolling is carried out.

In the construction process of the urban trunk road, when the step of protecting the bed side slope in the roadbed excavation process is carried out, the pit and the groove on the bed side slope are filled by adopting step excavation masonry.

The construction process of the urban trunk road further comprises a special roadbed filling step, a structure rear roadbed filling step, a filling and digging junction and a steep slope roadbed filling step when a roadbed filling process is carried out;

when the special roadbed filling step is carried out, the method comprises a pond section filling procedure, a soft soil section filling procedure and a low filling shallow digging section filling procedure;

when a pond section filling process is carried out, water is pumped, desilting, airing and leveling are carried out within the range of a roadbed, then a layer of bottom geogrid is laid on a base, broken stones are filled on the bottom geogrid in a layered mode to the original ground, the backfill thickness of each layer is 0.5m, the bottom geogrid is wrapped in a reverse mode for 2m on the top surface of the broken stones, then soil is filled continuously until the soil is 30cm below the top surface of the roadbed, then a layer of upper geogrid is laid, graded broken stones with the thickness of 30cm are filled on the upper geogrid, the geogrid is wrapped in a reverse mode for 2m on the top surface of the graded broken stones, and finally a pavement structure is constructed;

when the soft soil section filling process is carried out, firstly removing silt to original state soil or excavating a soft soil layer, then replacing and filling 2m thick stone slag, then filling soil to be 30cm below the top surface of the roadbed in a layering manner, then laying a layer of geogrid, filling 30cm thick graded broken stone on the upper geogrid, reversely wrapping 2m of geogrid on the top surface of the graded broken stone, and finally constructing a pavement structure;

when the low-fill shallow-excavation section filling process is carried out, firstly removing road bed fillers or surface soil from the top surface of a road bed of a motor vehicle lane to a zero-fill road bed or a shallow-excavation road bed with the height of less than 80cm from the ground, judging whether the soil quality meets the filler requirement, if so, turning over and drying and compacting, and if not, carrying out over excavation to the depth of 80cm and then carrying out filling treatment; whether the underground water level is higher or not is also observed, if the underground water level is higher, graded broken stones with the thickness of 30cm are filled in the roadbed, and if the underground water level is normal, soil filling is filled in the roadbed;

when the step of filling the roadbed at the rear part of the structure is carried out, transition sections are arranged on the roadbed at the two sides of the bridge and the pipe culvert, excavated earth materials are symmetrically and hierarchically backfilled and rolled in the transition sections, namely the abutment areas of the bridge and the pipe culvert, and the compaction degree is not less than 96%;

when filling and digging junctions and filling steep slope roadbed, arranging a transition section at the longitudinal filling and digging junctions, wherein the length of a filling area of the transition section is not less than 10m, filling by adopting graded excavation stone slag, and arranging a transverse drainage infiltration ditch at the longitudinal filling and digging junctions; when the longitudinal or transverse gradient of the ground is more than 1: 5, in situ, the surface is excavated into an inwardly sloping reverse step.

In the construction process of the urban trunk road, when a pond section filling procedure and a soft soil section filling procedure of a special roadbed filling step are carried out, the longitudinal and transverse tensile stress of the geogrid is more than 30kN/m, and the superposition length is not less than 15 cm; the maximum grain size of the graded broken stone is not more than 15 cm.

In the construction process of the urban trunk road, when filling and digging boundaries and filling steep slope roadbed, the cross section of the drainage seepage ditch is in an isosceles inverted trapezoid shape, the length of the bottom plate is 40cm, the height of the bottom plate is 50cm, and the slope degree is 1: 0.5.

The construction process of the urban trunk road has the following characteristics:

1) when the roadbed at the rear of the structure is filled, transition sections are arranged on the roadbed at the two sides of the bridge and the pipe culvert, excavated earth materials are symmetrically and hierarchically backfilled in the transition sections, namely the platform back areas of the bridge and the pipe culvert and are rolled, and the compaction degree is not less than 96%; the uneven settlement of the roadbed on the two sides of the bridge and the pipe culvert is reduced, the phenomenon of bumping at the bridge head is reduced, and the driving comfort of road vehicles is improved;

2) when filling and digging junctions and steep slope roadbed filling are carried out, transition sections are arranged at longitudinal filling and digging junctions, and graded excavation stone ballast is adopted for filling, wherein the longitudinal or transverse slope of the ground surface is steeper than 1: 5, excavating the original surface into a reverse step which is inclined inwards by 2-4%, wherein the step width is not less than 2.0 m; the overall stability and the smooth pavement of the roadbed at the filling and digging transition section are ensured, and the generation of uneven settlement is avoided; and arranging a transverse drainage seepage ditch at the longitudinal filling and digging junction to prevent pore water or bedrock fracture water from permeating into the filling area to soften the embankment;

3) the invention adopts solid slope protection aiming at the filling pond section in the embankment side slope protection process so as to protect the roadbed from being eroded and washed by surface water;

4) when the asphalt concrete surface layer is constructed, the asphalt mixture is laid, and primary grinding, secondary grinding and final grinding are carried out, so that the viscosity, the wear resistance and the water resistance of the road are improved, the phenomenon that the aggregate is lost or the whole body falls off on the upper surface of the road can be effectively avoided, meanwhile, a large amount of water can be prevented from permeating the bottom of the road, and the phenomena of collapse, cracks and the like of the road caused by water seepage are avoided.

Drawings

Fig. 1 is a schematic view illustrating a roadbed excavation process in the construction process according to the present invention;

FIG. 2 is a schematic view illustrating a roadbed filling process according to the construction process of the present invention;

FIG. 3 is a schematic view of the construction process of the present invention for treating the roadbed at the pond section;

FIG. 4a is a schematic view of the construction process of the present invention for excavation of a soft soil section foundation;

FIG. 4b is a schematic view of the construction process of the present invention for filling a soft soil section foundation;

FIG. 5 is a schematic view of the construction process of the urban trunk road of the present invention for low fill subgrade treatment;

FIG. 6 is a schematic view of the construction process of the urban trunk road of the present invention for performing platform back treatment;

FIG. 7 is a schematic illustration of the filling of the longitudinal filling and excavating junction according to the construction process of the present invention;

fig. 8 is a schematic view of the construction process of the present invention for filling a steep and sloping embankment.

Detailed Description

The invention will be further explained with reference to the drawings.

Referring to fig. 1 to 8, the construction process of the urban trunk road of the present invention includes the following steps: construction preparation, roadbed excavation, roadbed filling, embankment side slope protection and pavement construction;

the construction preparation process comprises the following steps:

(1) determining a field working boundary line, investigating the current situation of the existing aboveground and underground public facilities, and measuring;

(2) measuring and lofting, namely performing full-line red line lofting by adopting a total station, and verifying the original design red line range;

(3) cleaning a field;

when the step of excavating the substrate is carried out, an excavation mode is determined according to terrain conditions, soil layer occurrence, cutting sections, the lengths of the cutting sections and the like; adopting a transverse step to excavate in a gentle cross slope section of the soil cutting; adopting layered excavation in a deep cutting section; assisting in artificial excavation close to the surface of the bottom layer of the foundation bed and the side slope; when the excavation is carried out from top to bottom, an excavator is adopted to be matched with a dump truck and a scraper to transport soil and stones (see figure 1);

when a foundation bed side slope trimming step is carried out, according to the measured position of the side pile, the soil cutting machine is excavated to a position which is 0.1-0.2 m close to the foundation bed side slope surface, the slope is manually trimmed, and the inserted link hanging line is manually brushed every time one layer is excavated, so that the slope surface is smooth and has no obvious local height difference; the pit and the groove on the side slope of the foundation bed are embedded and repaired by digging steps and masonry;

when the road bed compaction step is carried out, a heavy vibratory roller is adopted to longitudinally carry out along the road, static pressure is firstly carried out and then vibration pressure is carried out during rolling, the speed is slow firstly and then fast, the vibration is from weak vibration to strong vibration, and the maximum speed of the roller is not more than 4 km/h; the straight line section is longitudinally advanced and retreated from two sides to the middle, the curve section is longitudinally advanced and retreated from the inner side to the outer side, and the edge part is rolled for 2-3 times; the overlap of the transverse wheel tracks of the road roller is not less than 40cm, the overlap of the longitudinal wheel tracks of two sections adjacent to each other is not less than 2.0m, and the filling joints of the upper layer and the lower layer are staggered by 3m, so that no pressure leakage and no dead angle are realized; after finishing rolling of each layer, carrying out compaction test, compaction test and deflection value detection;

when the roadbed filling process is carried out, the roadbed filling process comprises general roadbed filling, special roadbed filling, roadbed filling and digging junction after a structure and abrupt slope roadbed filling;

the method for filling the roadbed generally comprises the following steps: measuring and lofting, treating a substrate, filling and rolling, filling and digging a joint construction and draining a filling section;

when the filling step is carried out, parallel operation is carried out by adopting a method of filling soil filler horizontally and hierarchically, longitudinally segmenting, paving by using a bulldozer, leveling by using a leveler and rolling by using a heavy vibrating road roller; the loose paving thickness of each layer of filling is not more than 30cm (see figure 2), when the top layer filling thickness is less than 10cm, the lower layer filling is turned loose to a certain depth and is rolled together with new filling; filling earth with different soil qualities in a layered manner, wherein the filling thickness of each filling earth is not less than 0.5 m;

when the step of filling and rolling is carried out, the filling is roughly leveled by a bulldozer, then the leveling is finely leveled by a leveler, and rolling is carried out after the leveling degree after the fine leveling is controlled to be less than 3 cm; firstly rolling for 2 times by adopting a vibratory roller with 15t, and then rolling by adopting a vibratory roller with the vibration force of more than 30t until the specified compaction degree is reached, and controlling the rolling width of the roadbed to be more than 50cm larger than the designed width so as to ensure the dense and stable slope;

when the filling section drainage construction step is carried out, drainage is carried out to the outer side of a side slope according to the transverse gradient of 2%, in the roadbed filling process, a road groove is built immediately after each layer of filling operation surface is rolled and formed, namely two road shoulders are formed on two sides of the roadbed by soil heaps to form the road groove, temporary drainage grooves are arranged on the side slope according to the interval of 20m, the temporary drainage grooves are built by woven bagged gravel or red bricks, and the bottom width of each temporary drainage groove is not less than 0.5 m;

when the special roadbed is filled, the filling comprises pond section filling, soft soil section filling and low filling shallow excavation section filling;

when filling the pond section, pumping water, dredging, airing and leveling in the range of a roadbed, then paving a layer of bottom geogrid on a substrate, filling broken stones on the bottom geogrid in layers to the original ground, wherein the backfill thickness of each layer is 0.5m, wrapping 2m on the top surfaces of the broken stones by using the bottom geogrid in a reverse mode, then continuously filling soil to be 30cm below the top surface of the roadbed, then paving a layer of upper geogrid, filling 30 cm-thick graded broken stones on the upper geogrid, wrapping 2m on the top surfaces of the graded broken stones by using the geogrid in a reverse mode, and finally constructing a pavement structure (see figure 3); the longitudinal and transverse tensile stress of the geogrid is more than 30kN/m, and the superposition length is not less than 15 cm; the maximum grain size of the graded broken stone is not more than 15 cm;

when filling a soft soil section, firstly removing silt to original state soil or excavating a soft soil layer, then replacing and filling 2m thick stone slag, then filling soil to be 30cm below the top surface of a roadbed in a layering manner, then laying a layer of geogrid, filling 30cm thick graded broken stone on the upper geogrid, reversely wrapping 2m of the geogrid on the top surface of the graded broken stone, and finally constructing a pavement structure; the longitudinal and transverse tensile stress of the geogrid is more than 30kN/m, and the superposition length is not less than 15 cm; the maximum particle size of the graded crushed stones is not more than 15cm (see fig. 4a and 4 b);

when the low-fill shallow-excavation section is filled, firstly removing road bed fillers or surface soil from the top surface of a road bed of the motor vehicle lane to a zero-fill road bed or a shallow-excavation road bed with the height of less than 80cm from the ground, judging whether the soil quality meets the filler requirement, if so, turning over and drying the soil to compact the soil, and if not, performing over excavation to the depth of 80cm and then replacing the filling soil; whether the underground water level is higher or not is also observed, if the underground water level is higher, graded broken stones with the thickness of 30cm are filled in the roadbed, and if the underground water level is normal, soil filling materials are filled in the roadbed (see figure 5);

when the roadbed at the rear of the structure is filled, transition sections are arranged on the roadbed at the two sides of the bridge and the pipe culvert, excavated earth materials are symmetrically backfilled in layers at the transition sections, namely the platform back areas of the bridge and the pipe culvert, and are rolled, and the compaction degree is not less than 96% (see figure 6); the uneven settlement of the roadbed on the two sides of the bridge and the pipe culvert is reduced, the phenomenon of bumping at the bridge head is reduced, and the driving comfort of road vehicles is improved;

when filling and digging junctions and filling steep slope roadbed, arranging a transition section at the longitudinal filling and digging junctions, wherein the length of a filling area of the transition section is not less than 10m, and filling is performed by adopting graded excavation stone slag, the particle size of the stone slag is less than 10cm, and arranging a transverse drainage infiltration ditch at the longitudinal filling and digging junctions; the cross section of the drainage seepage ditch is in an isosceles inverted trapezoid shape, the length of a bottom plate is 40cm, the height of the bottom plate is 50cm, and the slope degree is 1:0.5 (see figure 7) so as to prevent pore water or bedrock fracture water from permeating into a filling area to soften the embankment; when the longitudinal or transverse gradient of the ground is more than 1: 5, excavating an inward inclined reverse step on the surface in situ, wherein the step width is not less than 2.0 meters (see figure 8); the overall stability and the smooth pavement of the roadbed at the filling and digging transition section are ensured, and the generation of uneven settlement is avoided;

performing a embankment side slope protection process, and adopting grass planting protection when the height H of the embankment side slope is less than or equal to 3 m; when the height H of the embankment side slope is more than 3m, adopting a mortar rubble framework for protection; the filling pond section adopts solid revetments, the slope of which is 1:1.5, so as to protect the roadbed from being eroded and washed by surface water;

when the pavement construction process is carried out, the pavement structure sequentially comprises roadbed plain soil, a graded broken stone cushion layer, a cement stabilized broken stone base layer and an asphalt concrete surface layer from bottom to top;

the compaction degree of the roadbed plain soil of the motor vehicle lane road surface is not less than 95%, and the thickness of the graded broken stone cushion layer is 18 cm; the cement-stabilized macadam foundation layer comprises a 3.5mpa/7 d-grade cement-stabilized macadam subbase layer with the thickness of 20cm and a 4.0mpa/7 d-grade cement-stabilized macadam foundation layer with the thickness of 20 cm; the asphalt concrete surface layer comprises an emulsified asphalt lower sealing layer with the thickness of 1cm, an asphalt stabilized gravel layer with the thickness of 8cm, a medium particle type asphalt concrete lower surface layer with the thickness of 6cm and a fine particle type asphalt concrete upper surface layer with the thickness of 4 cm;

the compaction degree of the roadbed plain soil of the non-motor vehicle lane road surface is not less than 92%, and the thickness of the graded broken stone cushion layer is 20 cm; the cement-stabilized macadam foundation is 4.0mpa/7d grade and 20cm thick; the asphalt concrete surface layer comprises an emulsified asphalt lower sealing layer with the thickness of 0.6cm, a medium particle type asphalt concrete lower surface layer with the thickness of 6cm and a fine particle type asphalt concrete upper surface layer with the thickness of 4 cm;

the pavement construction process comprises the following steps: paving a graded broken stone cushion layer, constructing a cement stabilized broken stone base layer and constructing an asphalt concrete surface layer;

When the measurement lofting process is carried out, firstly, the center line measurement is carried out, and then the edge position is measured according to the center line and the design width; carrying out leveling elevation measurement lofting on every 10m of a straight line section and every 5m of a curve or a bent section, rechecking the elevation of the cement stabilized macadam base layer, if the elevation exceeds the designed elevation, chiseling to ensure the construction thickness of asphalt, and hanging a steel wire on a steel wire support according to the elevation to serve as a datum line of paving construction;

when the permeable asphalt and the lower seal coat are sprayed, the permeable asphalt is sprayed on the surface of the cement stabilized macadam base, and the penetration depth is not less than 5 mm; the permeable layer asphalt adopts slow-cracking sprinkling type cation emulsified asphalt, and the dosage is 0.7-1.5L/m²(ii) a When a lower seal coat is laid on the permeable asphalt, firstly, an asphalt spreading vehicle is used for spraying emulsified asphalt, the whole spreading width is kept to be uniformly sprayed in the spraying process, and the using amount is 0.9-1.3 Kg/m²(ii) a Paving the joints sprayed by the front vehicle and the rear vehicle by iron plates or building paper for 1-1.5 m to ensure good lap joint; when spraying in several steps, the longitudinal lap joint width is 100-150 mm; after the emulsified asphalt is sprayed, the aggregate spreader is used for spreading the stone chips immediately, and the using amount is 5-8 m³/1000m²(ii) a After the stone chips are spread, the stone chips are swept uniformly in time, so that the requirements of overall coverage, consistent thickness, no overlapping of the stone chips and no exposure of asphalt are met, when the local part is short of materials, the stone chips are properly found and supplemented, and excessive stone chips are swept out due to excessive accumulated materials; at the lap joint of the two frames, the first frame is kept for a time when the emulsified asphalt is sprayed, the width of 100-150 mm is not spread with stone chips, and the second frame is spread with the stone chips; after spreading the stone chips, do not need to waitAfter the whole section is completely spread, immediately rolling 3-4 times from the roadside to the center of the road by using a 6-8 t steel wheel road roller, and overlapping each layer of wheel tracks by 300 mm; the rolling speed does not exceed 2km/h at the beginning and can be increased properly later;

when the asphalt concrete mixing process is carried out, an intermittent mixer is adopted to mix the asphalt mixture for 30-50 s, the degree that the mixture is uniformly mixed and all mineral aggregate particles are completely coated with the asphalt mixture is determined by trial mixing;

when the asphalt concrete paving procedure is carried out, two pavers are adopted to carry out step operation, and the front-rear distance between the two pavers is kept to be more than 20 m; reserving a width of 10-20 cm at the front part of the spread layer for temporary rolling to serve as a height reference surface of a new spread layer, overlapping the spread layers of 5-10 cm, and finally performing bridging seam rolling in a hot seam mode to eliminate seams; the longitudinal seams of the upper layer and the lower layer are staggered by more than 15 cm; paving a reference surface with the length of 1m at the starting point of the connecting layer and the surface layer manually according to the paving width, multiplying the elevation of the reference surface by a loose paving coefficient according to the designed elevation, and adjusting a scale according to the paving thickness; the spreading machine retreats to the position of the reference surface, and the leveling plate is lowered to the reference surface; the paving is carried out according to a longitudinal straight line; the spreading speed is 1-2.9 m/min.

When in secondary rolling, a 10-15 t tire vibratory roller is used for heavy pressing for 4-6 times until the road surface is stable and compact, so that the road surface is formed, the rolling speed is 4-5 km/h, the overlapping width of adjacent rolling belts is 10-20 cm during rolling, the vibratory roller stops vibrating when reversing and starts vibrating after starting towards the other direction, and the mixture is prevented from forming a bulge; the temperature of the secondary rolling is not lower than 90 ℃;

when longitudinal joint processing is carried out, a thermal joint is needed when the joint of the main line and the intersection needs to be made; paving the crossroads, coating asphalt at the joint cutting positions, overlapping the main lines for 5-10 cm in width during paving, and shoveling after paving; during rolling, a road roller is positioned on a compacted road surface, the width of the road roller extending across a new paving layer is 15cm, then the new paving layer is rolled, the width of the road roller extending across the compacted road surface is 10-15 cm, so that seams are tight, the seams are kept at the positions of line drawing in a lane area as much as possible, and longitudinal seams of upper and lower layers are staggered by more than 200 mm;

when longitudinal seam processing is carried out, an oblique seam is adopted, namely the seams of the upper layer and the lower layer are staggered by more than 1 m; measuring the position of the uneven cross section by using a 3m ruler, wherein each section is not less than 4, cleaning the section during lapping, coating adhesive oil, and preheating; transversely rolling the joint, wherein a road roller is positioned on the compacted pavement and extends into the newly laid layer by 15cm during rolling, and then moving the newly laid layer by 15-20 cm after each time of rolling until all the newly laid layers are rolled, and then longitudinally rolling; when the adjacent spreading layers are formed and have longitudinal seams, a steel wheel road roller is firstly used for rolling once along the longitudinal seams, the width of the steel wheel road roller is 15-20 cm, then transverse rolling is carried out along the transverse seams, and finally normal longitudinal rolling is carried out.

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. A construction process of an urban trunk road comprises the following steps: construction preparation, roadbed excavation, roadbed filling, embankment side slope protection and pavement construction; it is characterized in that the preparation method is characterized in that,

when the broken stone mixture is paved and rolled, a paver is adopted during paving, and the paving speed is 1.5-2 m/min; when the working section with the paving interruption of more than 2h is finished, a seam is required to be arranged, a transverse seam is arranged perpendicular to the center line of the road, and a longitudinal seam is arranged along the direction of the center line of the road; the driving wheel faces the direction of the paver during rolling, and the road side drives the road to roll at low speed according to the principle that the road is light firstly and then heavy, static firstly and then vibrated, slow firstly and then fast, wheel tracks are overlapped, the lower part is dense firstly and then the upper part is dense; during rolling, the roller is pressed until no wheel mark exists by following the procedures of 3-4 times of initial pressing of the double steel wheels → 1-2 times of light vibration rolling → 3 times of heavy vibration rolling → 2 times of rolling of the steel wheel rolling; the wheel tracks are overlapped 1/2 wheel widths when the road roller rolls; the speed during rolling is 1.5-1.7 km/h for the first time to the second time, and the speed of each later time is 1.8-2.2 km/h;

when the permeable asphalt and the lower seal coat are sprayed, the permeable asphalt is sprayed on the surface of the cement stabilized macadam base, and the penetration depth is not less than 5 mm; the permeable layer asphalt adopts slow-cracking sprinkling type cation emulsified asphalt, and the dosage is 0.7-1.5L/m²(ii) a When a lower seal coat is laid on the permeable asphalt, firstly, an asphalt spreading vehicle is used for spraying emulsified asphalt, the whole spreading width is kept to be uniformly sprayed in the spraying process, and the using amount is 0.9-1.3 Kg/m²(ii) a Paving the joints sprayed by the front vehicle and the rear vehicle with iron plates or building paper for 1-1.5 m; when spraying in several steps, the longitudinal lap joint width is 100-150 mm; after the emulsified asphalt is sprayed, the aggregate spreader is used for spreading the stone chips immediately, and the using amount is 5-8 m³/1000m²(ii) a At the lap joint of the two frames, the first frame is kept for a time when the emulsified asphalt is sprayed, the width of 100-150 mm is not spread with stone chips, and the second frame is spread with the stone chips; after the stone chips are spread, immediately rolling 3-4 times from the roadside to the center of the road by using a 6-8 t steel wheel road roller, wherein each layer of wheel tracks are overlapped by 300 mm; the rolling speed does not exceed 2km/h at the beginning;

2. The process of claim 1, wherein the step of protecting the bed side slope of the roadbed excavation process is performed by using a step-excavation masonry for repairing the pits and grooves on the bed side slope.

3. The construction process of the urban trunk road according to claim 1, wherein when the roadbed filling process is performed, the construction process further comprises a special roadbed filling step, a structure back roadbed filling step, a filling and digging boundary and a steep slope roadbed filling step;

4. The construction process of an urban trunk road according to claim 3, wherein when a pond section filling process and a soft soil section filling process of a special roadbed filling step are performed, the longitudinal and transverse tensile stress of the geogrid is greater than 30kN/m, and the superposition length is not less than 15 cm; the maximum grain size of the graded broken stone is not more than 15 cm.

5. The construction process of the urban trunk road according to claim 3, wherein when the filling and digging junction and the steep slope roadbed filling steps are carried out, the cross section of the drainage infiltration ditch is an isosceles inverted trapezoid, the length of the bottom plate is 40cm, the height of the bottom plate is 50cm, and the slope degree is 1: 0.5.