CN115976899A - Geogrid capable of actively regulating humidity and accurately judging catastrophe and application thereof - Google Patents
Geogrid capable of actively regulating humidity and accurately judging catastrophe and application thereof Download PDFInfo
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Abstract
The invention discloses a geogrid capable of actively regulating humidity and accurately judging catastrophe and application thereof. The geogrid is composed of a plurality of grid unit bodies; each of the grid unit bodies includes a first main rib, a second main rib, a connection rib, a high-suction-force wicking fiber bundle, and a distributed sensing optical fiber. The geogrid disclosed by the invention is applied to roadbed engineering, can actively discharge redundant water in a soil body, keeps the interface shear strength of the original reinforced soil, captures the deformation and deformation position of the roadbed in an operation period in an all-around real-time manner, realizes the full-life health monitoring and the real-time disaster early warning of the roadbed, reduces the maintenance and repair cost of the roadbed in the operation period, and ensures the driving and life safety. The active drainage mechanism of the geogrid is determined by means of the unsaturated soil seepage theory, the strengthening effect of redundant water drainage on the shear characteristic of the rib soil interface is disclosed, the catastrophe early warning mechanism of the geogrid is clarified, and finally a systematic and comprehensive geogrid design method is established.
Description
Technical Field
The invention belongs to the field of low fill roadbed engineering, and particularly relates to a geogrid capable of actively regulating humidity and accurately judging catastrophe and application thereof.
Background
The geogrid can effectively reduce differential settlement of a filling subgrade and improve the subgrade strength and stability when being used as a reinforcement material, so that the geogrid is widely applied to highway and railway subgrade engineering. In practical engineering, geogrids are usually used in combination with coarse-grained soil with good permeability to achieve the best engineering effect. However, in plain areas (e.g. yellow river alluvial plains), soil with higher fine particle content is the road base filler that has to be used. Due to the obvious capillary phenomenon of fine soil and poor water stability, under the alternate action of natural activities such as rainfall, groundwater rise and the like, a serving roadbed (particularly a low fill roadbed) is in an overhumidity state all the year round, so that the rigidity and the strength of a soil body are obviously reduced, the interface frictional resistance of reinforced soil is reduced, the structural stability of reinforced soil is reduced, the problem of deformation and instability damage of the roadbed in a large range is caused, and further a series of pavement diseases such as pavement cracking, local collapse and the like are caused, and the economic loss is serious. Therefore, active regulation and control of the internal humidity state of the roadbed in service and accurate judgment of deformation and catastrophe characteristics are two problems to be solved urgently in construction, maintenance and curing of roadbed engineering.
First, in order to solve the problem of wet softening of the roadbed, researchers have studied physical drainage reinforcement (gravel layer, drainage fabric, etc.) and modified material curing (cement, lime, etc.). Among them, the drainage geogrid has become a research focus and focus in this direction as a geotechnical material with both functions of transverse drainage and reinforcement. In the current research results, the traditional drainage geogrid materials including drainage grooves, drainage pipes, drainage net mats and the like can only perform passive drainage under the action of gravity on soil bodies in a saturated or nearly saturated state, but the drained soil bodies are still in a saturated state, so that active drainage of roadbed soil bodies and active control of the water content of roadbed fillers cannot be realized, and the roadbed fillers are in a healthy humidity state for a long time. Therefore, the research results do not obtain good application effect in roadbed engineering, and the fundamental cure is difficult.
Secondly, the change of the humidity state is considered as a direct influence factor of potential deformation instability of various roadbeds, and in order to obtain the deformation characteristics of the serving roadbeds under the coupling action of full-section humidity redistribution and circulating traffic load, students mostly use a paving single-point displacement sensor and a settlement testing device to carry out indoor scale model tests and field full-scale test researches. However, the results of the study show that: the existing various high-precision displacement meters and testing devices can only realize the monitoring and evaluation of scattered points inside the roadbed, the obtained deformation characteristics are difficult to establish a comprehensive and reliable relationship with the humidity state inside the roadbed, the cost is high, the damage is easy, the theoretical guidance significance is insufficient, and the engineering application significance is not large. Therefore, a reliable material and a method for monitoring the deformation of the full section of the roadbed in real time by taking the humidity state of the roadbed into consideration are still lacked at present.
The research results do not relate to the novel composite geotechnical material concept and research which can actively discharge the excessive moisture in the unsaturated roadbed and realize real-time monitoring of roadbed full-section deformation, and the important theory and technology which need to be broken through urgently in the research direction of roadbed engineering and even geotechnical engineering are also provided. In addition, the research results do not relate to research on the moisture migration mechanism of the reinforced soil interface and the influence of the moisture migration on the strength characteristic of the reinforced soil interface, and a scientific theoretical basis cannot be provided for engineering design units; scientific and reasonable geogrid design application and evaluation methods are not established, engineering construction is mainly based on experience, construction is easily over-conservative, and construction cost is greatly increased.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide the geogrid capable of actively regulating and controlling humidity and accurately judging catastrophe and the application thereof.
The technical scheme for solving the technical problem is to provide the geogrid for actively regulating and controlling humidity and accurately judging catastrophe, and the geogrid is characterized by comprising a plurality of grid unit bodies; each grid unit body comprises a first main rib, a second main rib, a connecting rib, a high-suction wicking fiber bundle and a distributed sensing optical fiber;
the first main ribs, the second main ribs and the connecting ribs are arranged in rows and columns, the first main ribs and the second main ribs are arranged along the width direction of the roadbed, and the connecting ribs are arranged along the length direction of the roadbed; one end of each of the first main rib and the second main rib is connected with one connecting rib, and the other end of each of the first main rib and the second main rib is connected with the other connecting rib; a plurality of second main ribs are uniformly arranged between every two adjacent first main ribs; through grooves extending along the width direction of the roadbed are formed in the upper surfaces of the first main rib and the second main rib, and two ends of each through groove penetrate through the connecting rib and are communicated with the through grooves of the adjacent grid unit bodies; high-suction wicking fiber bundles are placed in the through grooves; the top surface of the high-suction wicking fiber bundle is used for absorbing redundant moisture in the soil body, and two ends of the high-suction wicking fiber bundle are exposed in the external natural environment; circular through holes are formed in the first main rib and the connecting rib along the respective axial directions; distributed sensing optical fibers are placed in the circular through holes; the distributed sensing optical fiber is arranged in the circular through hole in a sealing mode and used for accurately judging and identifying deformation and catastrophe of the roadbed.
Compared with the prior art, the invention has the beneficial effects that:
(1) The soil engineering grating is internally embedded with the wicking fiber, when external moisture invades, such as natural rainfall, underground water level rising and the like, the soil engineering grating can actively discharge redundant moisture in the roadbed through a suction gradient embedded between the inner part and the outer part of the roadbed, realize active drainage of roadbed soil in an unsaturated state, keep the interface shear strength of the original reinforced soil, simultaneously prevent a pot cover effect caused by internal moisture migration of the roadbed at the junction of the roadbed and a road surface and a water sac effect caused at the junction of the roadbed and the roadbed to a certain extent in an operation period, ensure that the internal moisture content of the roadbed is always in a healthy humidity state, effectively solve the difficult problem of humidifying and softening of the reinforced roadbed in the operation period and avoid the phenomenon of water damage of the reinforced roadbed.
(2) The geogrid can capture deformation and deformation positions of the roadbed in the operation period under the combined action of complex environmental conditions and traffic loads in an all-round and real-time manner, realize the full-life health monitoring and the real-time disaster early warning of the roadbed, reduce the maintenance and repair cost of the roadbed in the operation period, and ensure the driving and life safety.
(3) The invention combines the local annual average rainfall capacity and the underground water level fluctuation condition of the engineering, reasonably designs the layer number, the interval and the layout position of the geogrid aiming at different roadbed soil types, establishes a geogrid design application method through the indoor roadbed full-section scale model test contrast analysis, and scientifically guides the engineering application.
(4) The active drainage mechanism of the geogrid is determined by means of the unsaturated soil seepage theory, the strengthening effect of redundant moisture drainage on the shearing characteristic of the reinforced soil interface is disclosed, the catastrophe early warning mechanism of the geogrid is clarified, and finally a systematic and comprehensive geogrid design method is established.
Drawings
Fig. 1 is a front view of a geogrid according to embodiment 1 of the present invention;
fig. 2 is a left side view of the geogrid of embodiment 1 of the present invention;
fig. 3 is a top view of the geogrid of embodiment 1 of the present invention;
fig. 4 is a bottom view of the geogrid according to embodiment 1 of the present invention;
FIG. 5 is a cross-sectional view of a wicking fiber of example 1 of the invention;
fig. 6 is a structural view of a distributed sensing optical fiber of embodiment 1 of the present invention;
fig. 7 is an active drainage diagram of a two-layer geogrid of the present invention;
FIG. 8 is a force diagram of a single first or second main rib of the present invention;
fig. 9 is a schematic structural view of a complex environment simulation box having two layers of geogrids according to the present invention.
In the figure, a first main rib 1, a second main rib 2, a connecting rib 3, a through groove 4, a high-suction wicking fiber bundle 5, a circular through hole 6, a distributed sensing optical fiber 7, a wicking fiber 8, a drainage channel 9, a glass fiber 10, a silica cladding 11, an acrylic resin coating layer 12, a polyester sheath 13, a natural foundation 14, a compacted roadbed 15, a base layer and a subbase layer 16, an asphalt pavement 17, a geogrid 18, a rainfall infiltration 19, a groundwater level 20, a groundwater level rise 21, moisture evaporation 22, moisture migration 23, a complex environment simulation box 24, a gravel layer 25, compacted roadbed soil 26, a moisture sensor 27, a laser displacement meter 28, a sprinkler 29, an inlet water tank 30, a valve 31, a flow meter 32, an inlet pipe 33, and a traffic load simulation device 34.
Detailed Description
Specific examples of the present invention are given below. The specific examples are only for illustrating the present invention in further detail and do not limit the scope of the claims of the present invention.
The invention provides a geogrid (geogrid for short) capable of actively regulating humidity and accurately judging catastrophe, which is characterized in that the geogrid 18 is composed of a plurality of grid unit bodies; each grid unit body comprises a first main rib 1, a second main rib 2, a connecting rib 3, a high-suction wicking fiber bundle 5 and a distributed sensing optical fiber 7;
the first main ribs 1, the second main ribs 2 and the connecting ribs 3 are arranged in rows and columns, the first main ribs 1 and the second main ribs 2 are arranged along the width direction of the roadbed, and the connecting ribs 3 are arranged along the length direction of the roadbed (namely the driving direction); one end of each of the first main rib 1 and the second main rib 2 is connected with one connecting rib 3, and the other end is connected with the other connecting rib 3; a plurality of second main ribs 2 (3 in the embodiment) are uniformly arranged between every two adjacent first main ribs 1; the upper surfaces of the first main rib 1 and the second main rib 2 are respectively provided with a through groove 4 extending along the width direction of the roadbed, and two ends of each through groove 4 penetrate through the connecting rib 3, penetrate through the connecting rib 3 and are communicated with the through grooves 4 of the adjacent grid unit bodies; high-suction wicking fiber bundles 5 are placed in the through grooves 4; the top surface of the high-suction wicking fiber bundle 5 is used for absorbing redundant moisture in the soil body, and two ends of the high-suction wicking fiber bundle are exposed in the external natural environment; the inner parts of the first main rib 1 and the connecting rib 3 are respectively provided with a circular through hole 6 along the respective axial direction; a distributed sensing optical fiber 7 is arranged in the circular through hole 6; the distributed sensing optical fiber 7 is hermetically arranged in the circular through hole 6, is not exposed in the external natural environment, and is used for accurately judging and identifying deformation and catastrophe of the roadbed.
Preferably, the raw materials of the first main rib 1, the second main rib 2 and the connecting rib 3 are made of High Density Polyethylene (HDPE) materials through high temperature extrusion and net punching and stretching.
Preferably, in each grid unit body, the distance between two adjacent first main ribs 1 is 12-16 cm, and the distance between two adjacent second main ribs 2 is 3-4 cm; the width of each of the first and second main ribs 1 and 2 is 10 to 12mm (preferably 10 mm), and the width of the connecting rib 3 is 15 to 18mm (preferably 15 mm); the thicknesses of the first main rib 1, the second main rib 2 and the connecting rib 3 are all 5 to 7mm (preferably 5 mm); the width of the through groove 4 is 5 to 6mm, and the depth is 1.5 to 2mm (preferably 1.5 mm).
Preferably, the high suction wicking fiber bundle 5 is woven from a number of wicking fibers 8; the cross section of each wicking fiber 8 is formed by connecting N cross-shaped fibers in the same direction, and the length of the cross section in the connecting direction is 30-50 mu m; the cross section of the shape is such that the wicking fiber 8 has a larger specific surface area and capillary force, and thus is more hygroscopic; the wicking fibres 8 have drainage channels 9; the water absorbed by the wicking fiber 8 is gathered at the drainage channel 9, and the water is subjected to water migration 23 through the drainage channel 9 under the traction action of the suction gradient, so that the redundant water in the soil body is discharged; the axial distance between adjacent drainage channels 9 is 5-12 μm; the tensile strength of the high suction wicking fiber bundle 5 at a strain of 2% is 7 to 15.8kN/m.
Preferably, the circular through hole 6 is located on the central axis of the first main rib 1 and the connecting rib 3. The diameter of the circular through hole 6 is 1-2 mm, and is consistent with the outer diameter of the distributed sensing optical fiber 7.
Preferably, the distributed sensing optical fiber 7 is composed of a glass fiber 10, a silica cladding 11, an acrylic resin coating layer 12 and a polyester sheath 13 from inside to outside; the optical signal is adopted for information transmission, and the optical fiber has the advantages of strong spatial resolution, strong anti-interference capability, small volume, simple wiring, stable remote data transmission and the like; an external Brillouin Optical Time Domain Reflectometer (BOTDR) can perform distributed monitoring on axial strain along the optical fiber, and then uneven deformation caused by wetting and softening in the roadbed is obtained.
Preferably, the mechanism for active drainage of the geogrid 18 reinforced subgrade is:
the road structure comprises a natural foundation 14, a compacted roadbed 15, a base layer and subbase layer 16 and an asphalt pavement 17 from bottom to top in sequence; the geogrid 18 is formed by a plurality of grid unit bodies; according to engineering requirements, a plurality of layers of geogrids 18 are uniformly laid in the compacted roadbed 15 at intervals, and two ends of the first main rib 1 and the second main rib 2 are directly exposed to the external natural environment;
when rainfall infiltrates 19 or the groundwater level rises 21, the geogrid 18 can absorb the excess moisture in the soil body; the moisture content of the geogrid 18 inside the roadbed increases to cause the suction force of the geogrid 18 to gradually decrease, and the suction force of the geogrid 18 exposed in the external natural environment is gradually increased due to moisture evaporation 22, so that a suction force gradient (the suction force gradient is the suction force difference) is formed between the inner geogrid 18 and the outer geogrid 18; moisture migration 23 towards the two ends occurs under the traction action of the suction gradient, so that the lateral active discharge of the excess moisture inside the roadbed is realized.
The invention also provides an application of the geogrid 18 in actively regulating and controlling the humidity of the roadbed, which comprises the following specific steps:
a1, determining the optimal water content of a soil sample used for a proposed roadbed project under the condition of maximum dry density and the corresponding substrate suction, and determining the water content of an geogrid 18 under the condition of the substrate suction through an indoor pressure plate instrument test, namely the water-containing state when the geogrid is laid;
step A2, developing an indoor water migration test: preparing a plurality of cubic samples (with side length of 200-300 mm) under the conditions of optimal water content and maximum dry density, and then humidifying to different water contents as initial water contents of the samples, wherein the initial water contents of every two samples are the same; stacking the samples with the same initial water content, and sandwiching the geogrid 18 in the step A1, and ensuring good contact of the three; measuring the average drainage rate and the total drainage amount of the geogrid 18 to different initial water content samples, establishing the relationship among the area of the geogrid 18, the initial water content of the sample, the average drainage rate and the total drainage amount, and establishing the relationship between the initial water content of the cubic sample and the final water content after drainage is finished;
step A3, determining the arrangement position of the geogrid 18 according to the position of the compacted roadbed 15 which is easily damaged by external moisture; determining the size, the layer number and the spacing of the geogrids 18 according to the annual water content state of the constructed local roadbed soil and the relationship established in the step A2;
a4, obtaining a shear displacement curve of the reinforced soil interface under the condition of different water contents through an indoor interface shear test, and judging the interface shear type according to the evolution trend of the shear displacement curve of the reinforced soil interface, wherein the interface shear type is an interface shear hardening model or an interface shear softening model; and fitting test data by using a formula (1) to obtain the parameters a and b or p, q and r of the reinforced soil interface:
in the formula (1), tau is the shear stress of the reinforced soil interface; u is the shearing displacement of the reinforced soil interface;
and A5, fitting according to the reinforced soil interface parameters under different water contents to obtain an empirical relationship between the water content of the interface soil body and each reinforced soil interface parameter, and obtaining the contribution of the active drainage function of the geogrid 18 to the shear characteristic of the reinforced soil interface for the engineering design of the reinforced roadbed.
The invention also provides an application of the geogrid 18 in the aspect of monitoring the catastrophe of the roadbed in real time, which comprises the following specific steps:
step B1, injecting pulsed light into one end of the distributed sensing optical fiber 7, when the distributed sensing optical fiber 7 is axially strained, receiving a back natural Brillouin scattering signal by the BOTDR at the same end to obtain Brillouin frequency drift (namely Brillouin frequency shift) of scattered light, and calculating the distance Z from the deformation occurrence position (namely roadbed deformation occurrence position) of the distributed sensing optical fiber 7 to the BOTDR by the formula (2):
in the formula (2), c is the speed of light in vacuum, T is the time interval from the emission of pulsed light to the reception of scattered light, and n is the refractive index of the distributed sensing fiber 7;
and B2, calculating the strain epsilon of the distributed sensing optical fiber 7 according to the Brillouin frequency shift obtained in the step B1 by using a formula (3):
in the formula (3), epsilon 0 And ε is the axial strain before and after measurement, v B (ε 0 ) And v B (epsilon) is Brillouin frequency shift before and after measurement, and C is a strain proportionality constant (0.05 MHz/. Mu.. Epsilon.);
and step B3, according to the deformation epsilon and the deformation occurrence position of the distributed sensing optical fiber 7, judging the damage mode of the wetted and softened roadbed, namely local damage or overall collapse.
Preferably, the application of the geogrid 18 in the aspect of disaster real-time monitoring of the roadbed further comprises the following steps:
in step B4, when the wetted compacted roadbed 15 is greatly deformed under the action of traffic load, the geogrid 18 may be pulled out or broken, so as to enter a failure mode:
in the first failure mode, for the same stress state, when the pulling failure mode is in a critical state, the geogrid 18 needs to satisfy the mechanical balance of the formula (4):
in the formula (4), σ f Tensile Strength, t and l, of geogrid 18 cr The thickness of the geogrid 18 and the effective length in a critical state are respectively, x is the distance between a certain point and the end part of the geogrid 18, and tau is a ribThe shear stress at the earth interface, τ (x), is a function of the distribution of shear stress at the earth-reinforced interface along the length of the geogrid, the integral of the function along the length of the geogrid
Namely the acting force of the reinforced soil interface with unit width;
and for the same stress state, when the pull-out failure mode is in a critical state, according to the Mokolun criterion, the shear failure strength of the reinforced soil interface meets the mechanical balance of the formula (5):
in the formula (5), τ f Shear failure strength of the soil interface, c gs Is the friction angle of the soil interface of the reinforcement v In order to provide the normal stress, the stress,
the apparent cohesive force of the reinforced soil boundary surface;
the invention also provides a method for judging the failure mode of the geogrid 18, which comprises the following specific steps:
step C1, effective length l under critical state of geogrid 18 cr When the shear failure strength is achieved within the range, the maximum acting force generated by the reinforced soil interface in unit width is as shown in formula (6):
step C2, under the conditions of the same compactness, water content and stress state, a certain critical effective length exists to judge the pulling-out and pulling-out failure modes of the geogrid 18, and the critical effective length l cr Calculated by equation (7):
step C3, according to the main ribs l (the main ribs comprise a first main rib 1 and a second main rib 2) and l cr Determine the failure mode of geogrid 18: when l is more than l cr When the circuit is in a pulling failure mode; when l is less than or equal to l cr When it is in the pull-out failure mode.
The invention also provides an application of the geogrid 18 in the aspect of design parameter selection in roadbed engineering practice, which is characterized in that the design parameter selection is performed by means of an indoor model test, and the method comprises the following steps:
step D1, building a complex environment simulation box 24:
(D1.1) building a geogrid reinforced roadbed model, and performing an expanded roadbed full-section reduced scale model test (building the geogrid reinforced roadbed model according to the reduced scale proportion of 1: the filling materials used for constructing the roadbed model are as follows from bottom to top in sequence: a gravel layer 25 of 0.2-0.3 m (preferably 0.3 m), compacted roadbed soil 26 of 0.6-0.8 m (preferably 0.8 m) and a gravel layer 25 of 0.2-0.3 m (preferably 0.3 m), wherein the upper and lower gravel layers are arranged to prevent direct erosion damage to the roadbed soil caused by rainfall infiltration 19 and groundwater level rise 21 respectively, and the final control target compaction degree is 96%; in the construction process, a plurality of moisture sensors 27 are uniformly arranged in the compacted roadbed soil 26 to measure the change of the moisture state of the roadbed soil; a plurality of laser displacement meters 28 are arranged at the top of the complex environment simulation box 24 to capture the deformation of the roadbed under the action of the cyclic dynamic load; the size of the built geogrid reinforced roadbed model is as follows: an upper bottom 1.2-1.4 m, a lower bottom 5.4-6.0 m, a height 1.4-1.5 m, a slope gradient 1.5-1.6 (preferably, the upper bottom 1.2m, the lower bottom 5.4m, the height 1.4m, the slope gradient 1.5;
(D1.2) building an external device for simulating the environmental load:
in order to simulate rainfall, a proper amount of sprinkling nozzles 29 are arranged at the top of the complex environment simulation box 24, and the complex environment simulation box can cover the whole roadbed structure;
in order to simulate the change of the underground water level, an underground water simulation device is arranged at the bottom of the complex environment simulation box 24; the groundwater simulation device comprises a water inlet tank 30, a valve 31, a flow meter 32 and a water inlet pipe 33; the water inlet tank 30 is filled with water, one end of the water inlet pipe 33 is communicated with the water outlet of the water inlet tank 30, the other end of the water inlet pipe extends into the gravel layer 25 at the bottom layer and is used for simulating the lifting change of the underground water level, and the valve 31 and the flowmeter 32 are sequentially arranged on the water inlet pipe 33 according to the water flow direction;
in order to simulate traffic load, a traffic load simulation device 34 is arranged at the top of the complex environment simulation box 24;
setting specific parameters of the complex environment simulation box 24 by combining the local annual average rainfall and the underground water level fluctuation condition of the project;
d2, setting a circulating dynamic load amplitude according to the road subgrade design specification (JTG D30-2015) and the reduced scale of the subgrade model in China; after the drainage of the geogrid 18 is finished, applying dynamic load to the roadbed to obtain the elasticity and accumulated plasticity behaviors of the soil body, and checking the elastoplasticity deformation of the roadbed soil in the loading process by using the distributed sensing optical fiber 7;
preferably, in step D2, the cyclic dynamic load amplitude is set to 60kPa.
D3, designing different working conditions, namely designing the layer number, the interval and the arrangement position of the geogrid 18 aiming at different roadbed soil types, and repeating the steps D1 and D2;
preferably, in the step D3, the roadbed soil is sand, silt or clay; the number of layers of geogrid 18 can be 1, 2 or 3; the spacing may be 0.3, 0.6, 0.9m; the layout position can be in three ways: the method comprises the following steps of (1) top and bottom of a roadbed, (2) top and bottom of the roadbed, and (3) top and bottom of the roadbed and positions close to side slopes.
And D4, summarizing and summarizing all working condition results obtained in the step D3, and optimizing the original design scheme on the basis of the spatial distribution characteristics of the humidity of the full section of the roadbed, the rigidity of the top of the roadbed and the deformation evolution law to obtain the design method of the geogrid 18.
Example 1
In each grid unit body, three second main ribs 2 are uniformly arranged between every two adjacent first main ribs 1; the distance between two adjacent first main ribs 1 is 12-16 cm, and the distance between two adjacent second main ribs 2 is 3-4 cm; the widths of the first main rib 1 and the second main rib 2 are both 10mm, and the width of the connecting rib 3 is 15mm; the thicknesses of the first main rib 1, the second main rib 2 and the connecting rib 3 are all 5mm; the width of the through groove 4 is 5-6 mm, and the depth is 1.5mm. The mesh size was 220mm by 30mm.
A circular through hole 6 is located on the central axis of the first main rib 1 and the connecting rib 3. The diameter of the circular through hole 6 is 2mm and is consistent with the outer diameter of the distributed sensing optical fiber 7.
The maximum measuring range of the distributed sensing optical fiber 7 is 5000 mu epsilon, and the distributed sensing optical fiber consists of a glass fiber 10 with the diameter of 10 mu m, a silica cladding 11 with the diameter of 300 mu m, an acrylic resin coating layer 12 with the diameter of 800 mu m and a polyester sheath 13 with the diameter of 1mm from inside to outside.
Nothing in this specification is said to apply to the prior art.
Claims (10)
1. A geogrid capable of actively regulating humidity and accurately judging catastrophe is characterized in that the geogrid is composed of a plurality of grid unit bodies; each grid unit body comprises a first main rib, a second main rib, a connecting rib, a high-suction-force wicking fiber bundle and a distributed sensing optical fiber;
the first main ribs, the second main ribs and the connecting ribs are arranged in rows and columns, the first main ribs and the second main ribs are arranged along the width direction of the roadbed, and the connecting ribs are arranged along the length direction of the roadbed; one end of each of the first main rib and the second main rib is connected with one connecting rib, and the other end of each of the first main rib and the second main rib is connected with the other connecting rib; a plurality of second main ribs are uniformly arranged between every two adjacent first main ribs; through grooves extending along the width direction of the roadbed are formed in the upper surfaces of the first main rib and the second main rib, and two ends of each through groove penetrate through the connecting rib and are communicated with the through grooves of the adjacent grid unit bodies; high-suction wicking fiber bundles are placed in the through grooves; the top surface of the high-suction wicking fiber bundle is used for absorbing redundant moisture in the soil body, and two ends of the high-suction wicking fiber bundle are exposed in the external natural environment; circular through holes are formed in the first main rib and the connecting rib along the respective axial directions; distributed sensing optical fibers are placed in the circular through holes; the distributed sensing optical fiber is arranged in the circular through hole in a sealing mode and used for accurately judging and identifying deformation and catastrophe of the roadbed.
2. The geogrid capable of actively regulating humidity and accurately judging catastrophe according to claim 1, wherein in each grid unit body, the distance between every two adjacent first main ribs is 12-16 cm, and the distance between every two adjacent second main ribs is 3-4 cm; the width of the first main rib and the width of the second main rib are both 10-12 mm, and the width of the connecting rib is 15-18 mm; the thicknesses of the first main rib, the second main rib and the connecting rib are all 5-7 mm; the width of the through groove is 5-6 mm, and the depth is 1.5-2 mm.
3. The geogrid capable of actively regulating humidity and accurately judging catastrophe according to claim 1, wherein the high-suction wicking fiber bundle is woven from a plurality of wicking fibers; the cross section of each wicking fiber is formed by connecting N cross-shaped fibers with the same direction, and the length of the connecting direction of the cross section is 30-50 mu m; the wicking fibers have drainage channels; the axial distance between adjacent drainage channels is 5-12 μm.
4. The geogrid capable of actively regulating humidity and accurately judging catastrophe according to claim 1, wherein the circular through holes are located on the central axis of the first main rib and the connecting rib.
5. The geogrid capable of actively regulating humidity and accurately judging catastrophe according to claim 1, wherein the distributed sensing optical fiber is composed of glass fiber, a silica cladding, an acrylic resin coating layer and a polyester sheath from inside to outside.
6. The application of the geogrid disclosed by any one of claims 1-5 in the aspect of actively regulating and controlling the humidity of a roadbed comprises the following specific steps:
a1, determining the optimal water content of a soil sample used for a proposed roadbed project under the condition of maximum dry density and the corresponding substrate suction, and determining the water content of an geogrid 18 under the condition of the substrate suction through an indoor pressure plate instrument test;
step A2, developing an indoor water migration test: preparing a plurality of cubic samples under the conditions of optimal moisture content and maximum dry density, and then humidifying the samples to different moisture contents to be used as initial moisture contents of the samples, wherein the initial moisture contents of every two samples are the same; stacking the samples with the same initial water content, and sandwiching the geogrid 18 in the step A1, and ensuring good contact of the three; measuring the average drainage rate and the total drainage amount of the geogrid 18 to different initial water content samples, establishing the relationship among the area of the geogrid 18, the initial water content of the sample, the average drainage rate and the total drainage amount, and establishing the relationship between the initial water content of the cubic sample and the final water content after drainage is finished;
step A3, determining the arrangement position of the geogrid 18 according to the position of the compacted roadbed 15, which is easy to be damaged by external moisture; determining the size, the layer number and the interval of the geogrids 18 according to the perennial water-containing state of the local roadbed soil for construction and the relationship established in the step A2;
step A4, obtaining a shear displacement curve of the reinforced soil interface under different water content conditions through an indoor interface shear test, judging the interface shear type according to the evolution trend of the shear displacement curve of the reinforced soil interface, and obtaining reinforced soil interface parameters a and b or p, q and r by utilizing fitting test data of formula (1):
in the formula (1), tau is the shear stress of the reinforced soil interface; u is the shearing displacement of the reinforced soil interface;
and A5, fitting according to the reinforced soil interface parameters under different water contents to obtain an empirical relationship between the interface soil body water content and each reinforced soil interface parameter, and obtaining the contribution of the active drainage function of the geogrid to the reinforced soil interface shearing property for the engineering design of the reinforced roadbed.
7. The application of the geogrid disclosed by any one of claims 1-5 in real-time monitoring of subgrade catastrophe comprises the following specific steps:
and step B1, injecting pulse light into one end of the distributed sensing optical fiber, when the distributed sensing optical fiber is subjected to axial strain, receiving a back natural Brillouin scattering signal by the BOTDR at the same end to obtain Brillouin frequency shift of scattered light, and calculating the distance Z from the deformation occurrence position of the distributed sensing optical fiber to the BOTDR by the formula (2):
in the formula (2), c is the light speed in vacuum, T is the time interval from the pulse light emission to the scattered light reception, and n is the refractive index of the distributed sensing optical fiber;
and B2, calculating the strain quantity epsilon of the distributed sensing optical fiber according to the Brillouin frequency shift obtained in the step B1 by using a formula (3):
in the formula (3), epsilon 0 And ε is the axial strain before and after measurement, v B (ε 0 ) And v B (epsilon) is Brillouin frequency shift before and after measurement respectively, and C is a strain proportionality constant;
and step B3, judging the damage mode of the roadbed after humidification and softening according to the deformation epsilon and the deformation occurrence position of the distributed sensing optical fiber.
8. The use of a geogrid according to claim 7 for real-time monitoring of subgrade catastrophe, further comprising the steps of:
and step B4, when the wetted compacted roadbed deforms greatly under the action of traffic load, the geogrid can be pulled out or broken, so that the compacted roadbed enters a failure mode:
for the same stress state and the failure mode I, when the breaking failure mode is in a critical state, the geogrid needs to satisfy the mechanical balance of the formula (4):
in the formula (4), σ f Tensile Strength of geogrid, t and l cr Respectively the thickness of the geogrid and the effective length in a critical state, x is the distance between a certain point and the end part of the geogrid, tau is the shear stress of the reinforced soil interface, tau (x) is a function of the distribution of the shear stress of the reinforced soil interface along the length of the geogrid, and the integral of the function along the length of the geogrid
Namely the acting force of the reinforced soil interface with unit width;
and for the same stress state, when the pull-out failure mode is in a critical state, according to the Mokolun criterion, the shear failure strength of the reinforced soil interface meets the mechanical balance of the formula (5):
in the formula (5), τ f Shear failure strength of the soil interface, c gs Is the friction angle of the soil interface of the reinforcement v In order to be the normal stress,
the apparent cohesion of the surface of the reinforced soil interface.
9. The application of the geogrid according to claim 8 in real-time monitoring of subgrade catastrophe is characterized in that the method for judging the failure mode of the geogrid comprises the following specific steps:
step C1, when the effective length l of the geogrid is in a critical state cr When the shear failure strength is achieved within the range, the maximum acting force generated by the reinforced soil interface with unit width is shown as the formula (6):
step C2, under the condition of the same compactness, water content and stress state, a certain critical effective length exists to judge the pulling-out and pulling-out failure modes of the geogrid, and the critical effective length l cr Calculated by equation (7):
step C3, according to the main ribs l and l cr Determining the failure mode of the geogrid: when l is more than l cr When the failure mode is the pull-out failure mode; when l is less than or equal to l cr When it is in the pull-out failure mode.
10. Use of a geogrid according to any of claims 1-5 for design parameter selection in roadbed engineering practice, wherein the design parameter selection is performed by means of an indoor model test, comprising the steps of:
step D1, building a complex environment simulation box:
(D1.1) building a geogrid reinforced roadbed model: the filling materials for building the roadbed model are sequentially from bottom to top: a crushed stone layer, compacted roadbed soil and a crushed stone layer; in the construction process, a plurality of moisture sensors are uniformly distributed in the compacted roadbed soil so as to measure the change of the moisture state of the roadbed soil; mounting a laser displacement meter at the top of the complex environment simulation box to capture the deformation of the roadbed under the action of the circulating dynamic load;
(D1.2) building an external device for simulating the environmental load:
in order to simulate rainfall, a water spray nozzle is arranged at the top of the complex environment simulation box to cover the whole roadbed structure;
in order to simulate the change of the underground water level, an underground water simulation device is arranged at the bottom of the complex environment simulation box; the underground water simulation device comprises a water inlet tank, a valve, a flow meter and a water inlet pipe; the water inlet water tank is internally provided with water, one end of the water inlet pipe is communicated with the water outlet of the water inlet water tank, the other end of the water inlet pipe extends into the gravel layer at the bottom layer and is used for simulating the lifting change of the underground water level, and the water inlet pipe is provided with a valve and a flowmeter;
in order to simulate traffic load, a traffic load simulation device is arranged at the top of the complex environment simulation box;
setting specific parameters of the complex environment simulation box by combining the local annual average rainfall and the underground water level fluctuation condition of the project;
d2, setting a circulating dynamic load amplitude according to the JTG D30-2015 and the reduced scale proportion of the roadbed model; after the drainage of the geogrid is finished, applying dynamic load to the roadbed to obtain the elasticity and accumulated plasticity of the soil body, and checking the elastoplasticity deformation of the roadbed soil in the loading process by using the distributed sensing optical fiber;
d3, designing the layer number, the interval and the layout position of the geogrids according to different roadbed soil types, and repeating the steps D1 and D2;
and D4, summarizing and summarizing all working condition results obtained in the step D3, and optimizing the original design scheme on the basis of the spatial distribution characteristics of the humidity of the full section of the roadbed, the rigidity of the top of the roadbed and the deformation evolution law to obtain the design method of the geogrid.
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN117403495A (en) * | 2023-12-11 | 2024-01-16 | 中南大学 | Embankment drainage structures and reinforced composite embankment |
Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002122414A (en) * | 2000-10-13 | 2002-04-26 | Maeda Kosen Co Ltd | Sheet body for detecting strain and its manufacturing method |
| CN104631254A (en) * | 2014-12-26 | 2015-05-20 | 石家庄铁道大学 | Construction method of geogrid reinforced clay edge-covered tailing subgrade |
| CN204385575U (en) * | 2014-12-26 | 2015-06-10 | 石家庄铁道大学 | Fill Reinforced With Geogrids clay bound edge CHARACTERISTICS OF TAILINGS SAND roadbed |
| CN208266894U (en) * | 2018-04-24 | 2018-12-21 | 中国农业大学 | A kind of intelligent TGXG for soil-slope |
| KR101934513B1 (en) * | 2018-05-04 | 2019-01-02 | 주식회사 에코텍스 | A Geogrid layering apparatus for use in the installation of a geogrid for reinforcing the asphalt pavement road |
| CN109339023A (en) * | 2018-09-29 | 2019-02-15 | 湖南大学 | A kind of TGXG with drain function |
| CN109577122A (en) * | 2018-12-07 | 2019-04-05 | 哈尔滨工业大学 | A kind of vertical drainage road structure based on electro-osmosis method |
| CN110258226A (en) * | 2019-07-08 | 2019-09-20 | 深圳大学 | The intelligent TGXG captured for road reinforcement, pavement monitoring, traffic information |
| CN110984186A (en) * | 2019-11-25 | 2020-04-10 | 河海大学 | Self-water-absorption composite geogrid |
| CN113502836A (en) * | 2021-07-27 | 2021-10-15 | 中国长江三峡集团有限公司 | Drainage geogrid and supporting structure and method |
| CN215491563U (en) * | 2021-10-03 | 2022-01-11 | 牛立锴 | Geogrid of composite optical fiber |
-
2022
- 2022-12-28 CN CN202211692847.1A patent/CN115976899A/en active Pending
Patent Citations (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002122414A (en) * | 2000-10-13 | 2002-04-26 | Maeda Kosen Co Ltd | Sheet body for detecting strain and its manufacturing method |
| CN104631254A (en) * | 2014-12-26 | 2015-05-20 | 石家庄铁道大学 | Construction method of geogrid reinforced clay edge-covered tailing subgrade |
| CN204385575U (en) * | 2014-12-26 | 2015-06-10 | 石家庄铁道大学 | Fill Reinforced With Geogrids clay bound edge CHARACTERISTICS OF TAILINGS SAND roadbed |
| CN208266894U (en) * | 2018-04-24 | 2018-12-21 | 中国农业大学 | A kind of intelligent TGXG for soil-slope |
| KR101934513B1 (en) * | 2018-05-04 | 2019-01-02 | 주식회사 에코텍스 | A Geogrid layering apparatus for use in the installation of a geogrid for reinforcing the asphalt pavement road |
| CN109339023A (en) * | 2018-09-29 | 2019-02-15 | 湖南大学 | A kind of TGXG with drain function |
| CN109577122A (en) * | 2018-12-07 | 2019-04-05 | 哈尔滨工业大学 | A kind of vertical drainage road structure based on electro-osmosis method |
| CN110258226A (en) * | 2019-07-08 | 2019-09-20 | 深圳大学 | The intelligent TGXG captured for road reinforcement, pavement monitoring, traffic information |
| CN110984186A (en) * | 2019-11-25 | 2020-04-10 | 河海大学 | Self-water-absorption composite geogrid |
| CN113502836A (en) * | 2021-07-27 | 2021-10-15 | 中国长江三峡集团有限公司 | Drainage geogrid and supporting structure and method |
| CN215491563U (en) * | 2021-10-03 | 2022-01-11 | 牛立锴 | Geogrid of composite optical fiber |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117403495A (en) * | 2023-12-11 | 2024-01-16 | 中南大学 | Embankment drainage structures and reinforced composite embankment |
| CN117403495B (en) * | 2023-12-11 | 2024-03-08 | 中南大学 | Embankment drainage structures and reinforced composite embankment |
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