CN-122013621-A - Roadbed layered filling construction method under condition of secondary road maintenance, reconstruction and extension

CN122013621ACN 122013621 ACN122013621 ACN 122013621ACN-122013621-A

Abstract

A construction method for layered filling of roadbed under the condition of two-stage highway protection, reconstruction and expansion includes such steps as S1, measuring the deflection value of existing old roadbed, dividing construction area and passing area, setting traffic guiding facilities, S2, treating the substrate, determining the step digging parameters according to the slope of original ground, digging steps when the slope is steeper than 1:5, setting internal slope, S3, treating poor geology, soft soil roadbed by filling method, dredging the road section, polishing by piece of stone, S4, measuring the layer filling and settlement, determining the thickness of first layer filling, layering by water-penetrable filler, observing settlement, dynamically regulating filling progress, S5, quality detection and traffic recovery. The invention effectively solves the technical problems of difficult control of roadbed filling quality, large differential settlement of new and old roadbeds, difficult coordination of traffic organization and construction safety and the like under the condition of guarantor traffic construction.

Inventors

WEI QUAN
LIANG LUJIA
HE YULING
LIU KUIYANG
LAN YI
YANG LINHU
LI NIANRONG
LIAO RUNFA
NING GUOLIANG
HUANG CHAOJUN
PAN FUYUAN

Assignees

广西航务建设工程有限公司

Dates

Publication Date: 20260512
Application Date: 20260331

Claims (10)

1. The roadbed layered filling construction method under the condition of secondary road maintenance, reconstruction and extension is characterized by comprising the following steps: S1, construction preparation and detection evaluation, namely performing deflection value detection and bearing capacity evaluation on an existing old roadbed, determining a reconstruction and expansion range, dividing a construction area and a traffic area according to a detection result, and setting traffic guiding facilities; s2, base treatment, namely cleaning and compacting the original ground of the filled road section, determining step excavation parameters according to the gradient of a transverse slope of the original ground, excavating steps when the transverse slope is steeper than 1:5, and setting an internal inclined slope; S3, poor geological treatment, namely adopting a filling method to treat the soft soil roadbed according to geological investigation results, and adopting dredging back rubble to throw and fill the fish pond road section; S4, roadbed layered filling and settlement monitoring, namely determining the first layer filling thickness according to the deflection value of the old roadbed, adopting water-permeable filler to spread and roll from a lower position to a higher position in layers, performing settlement observation after 3 layers of filling are completed, and dynamically adjusting the upper layer filling progress according to the settlement rate; And S5, quality detection and traffic recovery, namely detecting the road foundation compactness and differential settlement, and removing temporary traffic facilities after the road foundation compactness and differential settlement are detected to be qualified, so that normal traffic is recovered.
2. The method for layered filling construction of roadbed under the condition of two-stage highway traffic-guiding and reconstruction and extension according to claim 1, wherein in the step S1, the setting of traffic-guiding facilities specifically comprises: adopting a half-width closed construction and half-width bidirectional passing mode, and adopting a conical barrel or a water horse to isolate the construction area from the passing area, wherein the distance between isolation facilities is not more than 5m; setting a speed limit sign in front of a construction area, wherein the speed limit is not more than 30km/h; an anti-collision guardrail is arranged between the construction area and the traffic lane, and the height of the guardrail is not less than 120cm; when the traffic flow of the passing area is more than 500 vehicles/hour, the construction area pauses the large-scale mechanical operation, and when the construction is performed at night, the operation area is provided with a flashing lamp and an LED guide mark.
3. The method for layered filling construction of roadbed under the condition of two-stage highway maintenance, reconstruction and extension according to claim 1, wherein in the step S2, the step excavation parameters are determined according to the original ground cross slope gradient: when the original ground transverse slope is between 1:5 and 1:3, the step width is 2m, and the inner slope gradient is 2%; When the original ground transverse slope is steeper than 1:3, the step width is increased to 2.5m, and the inner slope gradient is 3%; The steps are arranged step by step along the longitudinal direction of the road base, adjacent steps are smoothly connected, and the non-applicable materials in the excavation are abandoned and transported outwards.
4. The method for layered filling construction of roadbed under the condition of two-stage highway maintenance, reconstruction and extension according to claim 1, wherein in the step S3, the soft soil roadbed changing and filling method is processed according to the specific scheme determined by the soft soil layer thickness: When the thickness of the soft soil layer is not more than 2m, adopting mechanical and manual cooperation to dig out soft soil in a layered manner, adopting a dynamic feeler gauge to detect the bearing capacity of the substrate, and requiring the bearing capacity not to be lower than 120kPa; adopting graded broken stone with the mud content not exceeding 5% as a filling material, backfilling in layers, wherein the thickness of each layer is not more than 30cm, and adopting a vibratory roller to roll until the compaction degree is not less than 94%; and after the replacement is finished, a natural gravel transition layer with the thickness of 30cm is paved, and drainage blind ditches are arranged on two sides of the roadbed.
5. The method for layered filling construction of roadbed under the condition of two-stage highway construction according to claim 1, wherein in the step S3, the processing of the fish pond section comprises the following steps: Adopting a centrifugal pump to dry ponding, dredging to an undisturbed soil layer, and adopting a staged dredging mode when the sludge depth exceeds 1 m; the substrate is provided with a drainage slope with the gradient of 2% after dredging, and a step-shaped slope is excavated along the longitudinal direction; The method comprises the steps of adopting lamellar stones with the grain diameter not smaller than 30cm to carry out layered casting and filling, placing large lamellar stones on a bottom layer, adopting a bulldozer to match with a vibratory roller to carry out rolling for 4-5 times, and adopting stone scraps to fill gaps of the lamellar stones; Detecting by adopting a sedimentation observation method after rolling, wherein the continuous 3-day sedimentation amount is less than 2mm, and is regarded as qualified.
6. The method for layered filling construction of roadbed under the condition of two-stage highway maintenance and reconstruction as set forth in claim 1, wherein in the step S4, the first layer filling thickness is determined according to the old roadbed deflection value: When the deflection value of the old roadbed is not more than 2.0mm, the filling thickness of the first layer is 25-30cm; When the deflection value of the old roadbed is larger than 2.0mm, the filling thickness of the first layer is 15-20cm; the filling thickness of each subsequent layer is 25-30cm, the rolling is carried out by adopting a vibratory roller, the longitudinal lap joint is not less than 30cm, and the transverse lap joint is not less than 50cm.
7. The method for layered roadbed filling construction under the condition of two-stage highway maintenance, reconstruction and extension according to claim 1, wherein in the step S4, the water seepage filler is selected from the following standard: the maximum particle size of the filler is not more than 10cm, the mud content is not more than 3%, and the permeability coefficient is not less than 1X 10 -3 cm/s; Controlling the water content of the filler within a range of +/-2% of the designed water content, and adjusting the filler by tedding or sprinkling when the water content exceeds the designed water content; and 5-8% of cement is mixed in the filler in the range of the junction of the new roadbed and the old roadbed for stabilizing treatment.
8. The method for layered roadbed filling construction under the condition of two-stage highway maintenance and reconstruction and extension according to claim 1, wherein in the step S4, the settlement monitoring and dynamic adjustment comprises: Setting a settlement observation point at every 50m at the joint of the new roadbed and the old roadbed, and observing once after 3 layers of filling are completed; When the single settlement amount is larger than 15mm or the settlement rate is larger than 10 mm/day, suspending the upper layer filling, and continuing the construction after the pre-pressing time is prolonged until the settlement rate is smaller than 5 mm/day; and (3) pushing the filling boundary from the lower part to the higher part layer by layer, wherein the filling range of each layer exceeds the boundary line by not less than 1m, filling the longitudinal boundary and the transverse boundary uniformly, and rolling to achieve compactness and no splice mark.
9. The method for layered filling construction of roadbed under the condition of two-stage highway maintenance, reconstruction and extension according to claim 1, wherein when the original road width cannot meet the traffic demand, setting temporary sidewalk, and setting temporary sidewalk standard as follows: The width of the channel is not less than 3.5m, the longitudinal slope is not more than 3%, and the radius of the curve is not less than 15m; the compactness of the road bed is not less than 90%, and the flatness is not more than 30mm; Isolation facilities and warning marks are arranged between the sidewalk and the construction area.
10. The method for layered filling construction of roadbed under the condition of two-stage highway maintenance and reconstruction and extension according to claim 1, wherein in the step S5, the quality detection standard is as follows: The compactness of the range of 0-0.8m below the top surface of the roadbed is not less than 96%, and the compactness of the range of 0.8-1.5m below the top surface of the roadbed is not less than 94%; The differential settlement of the combination part of the new roadbed and the old roadbed is not more than 15mm; and after the construction is finished, removing temporary facilities, recovering original pavement markings and signs, and checking and accepting passing conditions by a joint traffic management department.

Description

Roadbed layered filling construction method under condition of secondary road maintenance, reconstruction and extension Technical Field The invention relates to the technical field of road engineering construction, in particular to a roadbed layered filling construction method under the condition of secondary road maintenance, reconstruction and extension. Background Along with the continuous increase of traffic demands in China, secondary highway reconstruction and expansion projects are increasingly increased. Unlike newly built roads, the reconstruction and expansion engineering needs to be constructed under the condition of maintaining the existing road traffic, namely' construction while traffic. Such engineering faces a number of technical challenges: firstly, a construction site is narrow, construction and traffic are parallel, so that the operation space is limited, space conflict exists between construction machinery and passing vehicles, and the problem of dynamically adjusting the construction operation according to traffic flow is solved; Secondly, the differential settlement control of the new roadbed and the old roadbed is difficult, a stable structure system is formed on the existing road through long-term operation, the original mechanical balance is broken through the widening construction, longitudinal cracks are easy to generate, the deflection value of the old roadbed directly influences the stability of the newly-filled roadbed, and filling parameters are required to be determined according to the state of the old roadbed; thirdly, the poor geological section is difficult to process, under complex geological conditions such as soft soil, high water level, fish pond passing and the like, the traditional filling process is easy to induce slope instability and roadbed subsidence, and targeted processing measures are needed to be adopted according to the geological conditions; Fourth, the construction process lacks dynamic monitoring mechanism, and traditional construction method is constructed according to fixed parameter, can't in time adjust the filling progress according to actual measurement sedimentation data, causes the road bed unstability easily. In the prior art, application number 202010338897.4 discloses a road base splicing construction method in expressway reconstruction and extension, but the method does not relate to linkage control of traffic organization and construction operation under the condition of secondary road traffic protection construction, and does not provide systematic control measures for the association of old roadbed deflection values and filling parameters. Application number 202211229699.X discloses a temporary construction method for highway reconstruction and expansion, but the method mainly aims at embankment widening, does not relate to determining step excavation parameters according to the gradient of an original ground cross slope, and also lacks a feedback mechanism for settlement monitoring and dynamic adjustment. Therefore, the prior art cannot systematically solve the technical problems that the roadbed filling quality is difficult to control, the difference between new and old roadbeds is large in settlement, the traffic organization and the construction safety are difficult to coordinate and the like under the condition of the secondary road maintenance, reconstruction and extension. Disclosure of Invention The invention aims to provide a roadbed layered filling construction method under the condition of two-stage road maintenance, reconstruction and extension, which solves the technical problems that the roadbed filling quality is difficult to control, the difference sedimentation of new and old roadbeds is large, the coordination of traffic organization and construction safety is difficult and the like under the condition of maintenance and extension. In order to achieve the above purpose, the invention adopts the following technical scheme: A roadbed layered filling construction method under the condition of secondary road maintenance, reconstruction and extension comprises the following steps: S1, construction preparation and detection evaluation, namely performing deflection value detection and bearing capacity evaluation on an existing old roadbed, determining a reconstruction and expansion range, dividing a construction area and a traffic area according to a detection result, and setting traffic guiding facilities; s2, base treatment, namely cleaning and compacting the original ground of the filled road section, determining step excavation parameters according to the gradient of a transverse slope of the original ground, excavating steps when the transverse slope is steeper than 1:5, and setting an internal inclined slope; S3, poor geological treatment, namely adopting a filling method to treat the soft soil roadbed according to geological investigation results, and adopting dredging back rubble to throw and fill the fish pond road sec