CN-122023704-A - Roadbed high slope hierarchical excavation and support construction method

CN122023704ACN 122023704 ACN122023704 ACN 122023704ACN-122023704-A

Abstract

The invention discloses a method for constructing a roadbed high slope by step excavation and support, and relates to the technical field of roadbed engineering construction. The method comprises four core steps of intelligent investigation and hierarchical planning, dynamic excavation and slope finishing, hierarchical cooperative support construction and intelligent monitoring and early warning. The method comprises the steps of constructing a three-dimensional geological model of a side slope through an intelligent investigation technology, dynamically adjusting the excavation order and the slope rate, customizing special supporting structures for different types of side slopes by adopting a three-level cooperative supporting system of a main supporting system, an auxiliary supporting system and an emergency standby supporting system, and realizing real-time monitoring and grading early warning by utilizing a monitoring device and an intelligent monitoring platform. The invention solves the problems of low investigation precision, lag in slope rate adjustment, insufficient support pertinence, untimely monitoring and early warning and the like in the traditional construction method, remarkably improves the safety, stability and efficiency of the high slope construction of the roadbed, and has good engineering application prospect.

Inventors

WANG FAAN
LONG BING
WANG XIN
LI JINYOU
DENG HAO
CHEN JUNLIN
SONG XINYU
TENG HONGJUN
ZHANG DALIANG
JIN WENTAO

Assignees

中铁贵州工程有限公司
中国铁建昆仑投资集团有限公司
贵州黔中高速公路开发有限公司

Dates

Publication Date: 20260512
Application Date: 20260415

Claims (10)

1. The method for the hierarchical excavation and support construction of the high side slope of the roadbed is characterized by comprising the following steps of: Step 1, intelligent investigation and hierarchical planning, namely constructing a three-dimensional geological model of a side slope by adopting an intelligent investigation technology, identifying the spatial distribution of poor geological bodies, carrying out stability numerical simulation based on the model, and dividing a dynamic excavation order and each level height, wherein the dynamic excavation order is adaptively adjusted according to the height of the side slope and the geological complexity; Step 2, a dynamic mapping model of the rock-soil property and the slope rate is established, a top-down layered and segmented excavation mode is adopted, the rock-soil modulus and the water content are detected in real time in the excavation process, and the slope rate is dynamically adjusted according to the detection result; step 3, carrying out hierarchical collaborative support construction, namely carrying out the hierarchical support construction by adopting a three-level collaborative support system of a main support, an auxiliary support and an emergency standby support based on a real-time stability dynamic analysis result of a three-dimensional geological model of the side slope after the side slope is excavated and trimmed in a first-order manner, and starting the next-order excavation and support operation after experience collection is qualified after the support is completed and the monitoring data of the side slope is stabilized within a preset threshold value range; And 4, intelligent monitoring and early warning, namely arranging a monitoring device at the excavation part of the side slope, monitoring the side slope supporting stress, the side slope displacement and the pore water pressure in real time, and transmitting monitoring data to a monitoring platform, wherein the monitoring platform realizes graded early warning based on a preset early warning model and dynamically adjusts excavation operation parameters.
2. The method for the hierarchical excavation and support construction of the high roadbed slope according to claim 1, wherein in the construction process of the three-dimensional geological model in the step 1, drilling rock core data and geological radar detection data are fused, a stratum parameter distribution cloud chart is generated by adopting an inversion algorithm, karst development areas are automatically identified, karst cave positions and scales are automatically identified, a detour or filling treatment path is planned, and a composite system of foam concrete and steel fibers is adopted as a filling material.
3. The method for constructing the roadbed high slope hierarchical excavation and support according to claim 1, wherein in the step 2, the dynamic mapping model of the rock-soil property and the slope rate is established based on a hybrid optimization algorithm fused by an improved BP neural network and a genetic algorithm, and a multi-factor coupling correction formula is combined, the rock-soil modulus and the water content are taken as input parameters, the slope rate is taken as an output parameter, and the dynamic mapping model calculation formula is as follows: ; wherein: , , , , The model weight coefficient is the value range of 0.1-0.8, m is the slope rate, and the output parameter is the rock-soil modulus, E is the input parameter; E 0 is the standard rock-soil modulus, and the value is 100MPa; The optimal water content of the rock-soil body is as follows:% and dimensionless; 、 the maximum and minimum water contents of the rock-soil body are shown in the units of percent and dimensionless; The internal friction angle of the rock-soil body is expressed in terms of degree, and c is the cohesive force of the rock-soil body and expressed in terms of kPa; is the natural density of the rock-soil mass, and the unit is kg/m3; the method is characterized in that the density is a reference density, the value of the density is 1800kg/m < 3 >, the value of g is a gravitational acceleration, the value of g is 9.81m/s < 2>, H is the current excavation step height, and the unit is m; For the non-linear correction coefficient(s), The method is used for correcting nonlinear influence of the rock-soil modulus on the slope rate; is an environmental influence coefficient, combines the rainfall and the air temperature change in the construction period to dynamically adjust, R is the rainfall of the month, The reference rainfall is 50mm, T is the average air temperature in month, Is the reference air temperature of 20 ℃.
4. The method for constructing the roadbed high slope hierarchical excavation and supporting construction according to claim 1 is characterized by further comprising the steps of reserving a protective layer at the slope after the first-order excavation reaches the preset broken-down platform elevation, evaluating the damage depth of the slope through a nondestructive detection technology, determining the stripping mode of the protective layer according to the damage condition to enable the slope to reach the designed slope rate, constructing the broken-down platform at the corresponding slope toe, connecting the broken-down platform with the slope, analyzing the stress relaxation area range of the rock-soil body through the wave velocity change of transmitting sound waves and receiving echoes by adopting an ultrasonic detector, and defining a critical cutting line of mechanical excavation and manual slope repairing by the end boundary of the stress relaxation area.
5. The method for hierarchical excavation and support construction of a high slope of a roadbed according to claim 4, wherein the step 2 further comprises the steps of firstly utilizing an excavator to strip soil outside a critical cutting line of mechanical excavation and manual slope repair, and then utilizing a manual hand-held machine to finish repair and strip the protective layer along a manual slope repair cutting surface.
6. The method for hierarchical excavation and supporting construction of a high slope of a roadbed according to claim 4, wherein the step 2 further comprises constructing a reverse slope drainage groove on the surface of the breaking table, wherein the reverse slope drainage groove is inclined from the outer edge of the breaking table to the inner side of the slope surface, so as to form a reverse slope structure for guiding runoffs to collect water to the inner side of the slope foot.
7. The method for constructing the roadbed high slope hierarchical excavation and support according to claim 1, wherein the step 3 is further characterized in that a composite structure of a telescopic anchor rod and a fiber concrete frame beam is selected as the main support of the rock slope, holes are formed through a directional drilling technology, a drilling track and a rock stratum structure form an included angle of 30-60 degrees, grouting is carried out by adopting a dual-stage process of low-pressure penetration grouting and high-pressure fracturing grouting, a flexible active net and a microbial mineralization grouting protective layer are arranged for auxiliary support, and anchor rod interfaces are reserved for frame beam nodes to preset emergency hollow grouting anchor rods.
8. The method for the hierarchical excavation and supporting construction of the high side slope of the roadbed according to claim 1 is characterized in that the step 3 further comprises the step that a self-adhesive biaxially-oriented geogrid, gradient density foam lightweight soil and ecological bag stacking combined structure is adopted for the main support of the soil side slope, a composite matrix containing a nano-scale silicate modifier is sprayed and sown on the outer side of the ecological bag by the auxiliary support, a permeable concrete cut-off wall with a drainage blind pipe is arranged at the toe of the slope, and a high-pressure grouting pipe with an internal pre-buried interval of 3-5 m and a depth of 1/2 of the height of the slope of the roadbed is used as an emergency standby support.
9. The method for the hierarchical excavation and support construction of the high side slope of the roadbed according to claim 1, wherein the step 3 is further characterized in that the main support of the bedding side slope adopts a large-diameter anti-slide pile with a built-in fiber bragg grating stress sensor, a carbon fiber board soil retaining plate and a pre-stress anchor cable combined system, the anchor cable is constructed according to a hierarchical loading and pressure stabilizing load holding and compensation tensioning process, and the locking load is 0.95 times of a design value.
10. The method for the hierarchical excavation and support construction of the high roadbed slope according to claim 1, wherein in the step 4, the monitoring device is fiber bragg grating sensors, the distribution density of the fiber bragg grating sensors is at least 3 per 100m < 2 >, the sensor packaging adopts a polytetrafluoroethylene shell, the monitoring frequency is 1 time/15 min, and the early warning accuracy rate is more than or equal to 95% through historical monitoring data and slope instability case training by an early warning model of an intelligent monitoring platform.

Description

Roadbed high slope hierarchical excavation and support construction method Technical Field The invention belongs to the technical field of traffic infrastructure construction, and particularly relates to a roadbed high slope hierarchical excavation and support construction technology. Background The high side slope of the roadbed is used as a key engineering structure in the construction of traffic infrastructures such as highways, railways and the like, and the construction quality of the high side slope of the roadbed is directly related to the operation safety and the service life of the whole traffic line. Along with the extension of traffic construction to mountain areas and hilly areas, the height and geological complexity of high roadbed slopes are continuously increased, and the traditional construction method gradually exposes a plurality of defects. In the investigation stage, the traditional investigation means rely on drilling sampling and geological mapping, and the problems of limited investigation range, low data precision, incomplete identification of bad geological bodies and the like exist, so that the three-dimensional geological characteristics of the side slope are difficult to accurately reflect, and the follow-up excavation and support design lacks scientific basis. In the excavation process, the slope rate is usually preset according to experience, cannot be dynamically adjusted according to the change of the actual rock-soil property, and the situation that the slope is too steep to cause instability or too slow to cause resource waste is easy to occur. Meanwhile, the slope is mostly trimmed by pure mechanical excavation or manual slope trimming, so that the slope flatness and damage degree are difficult to accurately control, and the stress effect of the follow-up supporting structure is affected. In the aspect of supporting construction, the traditional method mostly adopts a single supporting form, lacks pertinence and synergism, and cannot adapt to the stability requirements of slopes under different geological conditions. For example, the mechanical properties of the rock slope and the soil slope are obviously different, the ideal supporting effect is difficult to achieve by adopting the same supporting structure, the special instability risk exists on the bedding slope, and the sliding trend is difficult to effectively control by the traditional supporting method. In addition, the connection between the support construction and the excavation operation is not tight enough, the support is often carried out after the excavation is completed and is laid for a long time, and the risk of slope instability is increased. In the aspect of monitoring and early warning, the traditional monitoring means mostly adopt manual inspection and discrete sensor monitoring, and monitoring frequency is low, data transmission is lagged, early warning accuracy is not high, and the dynamic change of the side slope is difficult to master in real time, and the best emergency treatment opportunity is missed only when obvious instability signs appear on the side slope. Therefore, research and development of the roadbed high slope construction method capable of realizing intelligent investigation, dynamic excavation, collaborative support and real-time monitoring have important practical significance for improving construction safety, stability and efficiency. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a roadbed high slope grading excavation and support construction method which has the advantages of accurate investigation, controllable excavation, high support efficiency, timely monitoring and the like, and can effectively solve a plurality of problems existing in the traditional construction method. The technical scheme adopted by the invention is that the method for constructing the roadbed high slope hierarchical excavation and support comprises the following steps: Step 1, intelligent investigation and hierarchical planning An intelligent investigation technology is adopted to construct a three-dimensional geological model of the side slope, the spatial distribution of bad geological bodies is identified, stability numerical simulation is carried out based on the model, dynamic excavation orders and each level of height are divided, and the dynamic excavation orders are adaptively adjusted according to the height of the side slope and the geological complexity. Preferably, in the construction process of the three-dimensional geological model in the step 1, drilling rock core data and geological radar detection data are fused, a stratum parameter distribution cloud picture is generated by adopting an inversion algorithm, karst development areas are automatically identified, karst cave positions and scales are automatically identified, a detour or filling processing path is planned, and a composite system of foam concrete and steel fibers is adopted