CN216193712U - Lateral displacement structure for limiting freeze thawing roadbed - Google Patents
Lateral displacement structure for limiting freeze thawing roadbed Download PDFInfo
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- CN216193712U CN216193712U CN202122490616.XU CN202122490616U CN216193712U CN 216193712 U CN216193712 U CN 216193712U CN 202122490616 U CN202122490616 U CN 202122490616U CN 216193712 U CN216193712 U CN 216193712U
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Abstract
The utility model discloses a lateral displacement structure for limiting a freeze-thaw roadbed, which comprises filling piles, broken stone soil layers, fine soil layers, geogrids and prefabricated reinforced concrete pipes which are arranged in a staggered mode. The technology is suitable for treating the freezing and thawing alternation problem of the roadbed in the alpine region, the lateral deformation problem caused by the self weight of the roadbed can be effectively reduced under the freezing and thawing cycle of the roadbed, the vertical settlement and the lateral deformation control are divided into two main parts, the outside is in the exploration range of the roadbed, two rows of cement fly ash cast-in-place piles are arranged on two sides of the roadbed in a staggered mode, the inside is formed by alternately laying geogrids on a roadbed base body, prefabricated reinforced concrete pipes, gravel cushion layers, coarse grain cushion layers, fine grain soil cushion layers and a pavement, the roadbed body adopts an interaction mode of rigid-flexible combination, the two sides of the roadbed adopt active limiting lateral movement, and the inside and the outside are combined, so that the vertical settlement and the lateral deformation control of the freezing and thawing roadbed are realized.
Description
Technical Field
The utility model relates to the technical field of freeze-thaw roadbed processing, in particular to a lateral displacement structure for limiting a freeze-thaw roadbed.
Background
In recent years, with the construction of "one-by-one" in our country, the construction work of various important infrastructures in western regions has been vigorously developed. The average altitude of the Qinghai lake basin is 3000 meters, and belongs to the subadromic climate in plateau. The annual average temperature is about 1.5 ℃, the annual sunshine hours are about 2980 hours, the annual precipitation is about 400mm, the annual evaporation capacity is about 1581.75mm, and the seasonal climate condition of dry-wet cycle is formed. The water plant land is characterized in that a large continuously growing water plant land is arranged in the West sea area of the Qinghai lake basin, the material components of the water plant land mainly comprise silt and powder sticky particles, the water plant land comprises a gravel component, is loose and slightly dense and contains humus, and the water plant land belongs to typical poor soft soil in the area. The formation of the water grassland is caused by the fact that spring water grows on hillside near the Qinghai lake, partial ground surface is not smooth in drainage, and long-term water accumulation is caused. The complicated environmental conditions of abundant underground water, local water accumulation and dry-wet circulating climate can cause different degrees of influence on the rock-soil characteristics of the waterweed fields.
The main surface water system along the reinforced area is a khan naught river which develops in a corner mountain and belongs to a plateau river, the river generally flows in the north and south directions, the main flood season is 6 months to 9 months in the middle of each year, the main flood season is storm and snow mountain melt water, and the reinforced area has the characteristic of typical sudden rising and sudden falling of the river in the mountainous area. The project reinforcing area is positioned in a triangular zone, the topography is low, the gathering of surface water is facilitated, water is accumulated in local part all the year round, and a large area of marsh land is formed and is expressed as a 'water grassland'. The foundation rock-soil body of the 'water grassland' in the project reinforcement area is mainly silt, pebble soil and weathered granite amphibole, and because the water accumulation time is long and underground water is abundant, the soft soil layer of the surface layer turf reveals 1-3 m in thickness, brown gray is soft and plastic, and the thickness of the silt layer is 3-8 m.
The existing treatment method mainly aims to slow down the settlement and deformation of the roadbed, prevent the damage problems of pit slots on the road surface or the broken zone of an inwards concave pile caused by settlement, the cracking of the road surface and the like, and is not obvious in the aspects of improving the bearing capacity of the foundation, improving the load distribution of the road surface, preventing the lateral cracking and deformation of the roadbed and the like.
An effective solution to the problems in the related art has not been proposed yet.
SUMMERY OF THE UTILITY MODEL
The utility model aims to provide a structure for limiting the lateral displacement of a freeze-thaw roadbed, which limits the lateral deformation of the roadbed by combining an internal geogrid and external row piles, reduces the generation of a heat bridge effect by laying a prefabricated reinforced concrete pipe, and improves the transmission path of upper load so as to fulfill the aims of reinforcing the roadbed and limiting the deformation of the roadbed.
In order to achieve the purpose, the utility model provides the following technical scheme: a lateral displacement structure for limiting a freeze-thawing roadbed comprises staggered cast-in-place piles, broken stone soil layers, fine grain soil layers, geogrids and prefabricated reinforced concrete pipes, wherein the two sides of the freeze-thawing roadbed are respectively provided with a row pile, the row piles comprise two groups of staggered cast-in-place piles which are distributed in parallel and buried in the ground, the broken stone soil layers, the fine grain soil layers, the geogrids, the fine grain soil layers and the broken stone soil layers are arranged above the ground of the freeze-thawing roadbed in a staggered mode, the prefabricated reinforced concrete pipes are laid in the broken stone soil layers of a first layer and a second layer above the ground, the broken stone soil layers, the geogrids, the fine grain soil layers, the broken stone soil layers, the fine grain soil layers, the geogrids, the fine grain soil layers and the broken stone soil layers are sequentially distributed from top to bottom, prefabricated reinforced concrete pipes are laid in the gravel soil layers of the first layer and the second layer which are positioned below the ground, and the parts above the ground of the freeze-thaw roadbed and the parts below the ground of the freeze-thaw roadbed are pressed together through a rolling machine.
Compared with the prior art, the utility model has the following beneficial effects:
the freeze-thaw foundation is processed by combining rigid and flexible precast reinforced concrete pipes and geogrids, so that the freeze-thaw foundation forms a raft-like foundation, the transfer path of upper load can be improved, active soil pressure applied in advance is formed in a frozen soil excavation area by arranging double rows of piles on two sides of the foundation, the self-weight stress action of a filling body can be reduced after the filling of a roadbed body is finished, the extrusion effect on soil bodies on two sides is generated, after the precast reinforced concrete pipes, the geogrids and various cushion layers are processed in an interactive mode on the roadbed, the inner pores are reduced through repeated processing, the frost heaving damage caused by excessive water immersion can be prevented, and under the freeze-thaw cycle, the deformation of the roadbed and the foundation soil can be better limited due to the fact that the multilayer geogrids are arranged in the roadbed, and the geogrids are combined with external row piles to limit the lateral deformation of the roadbed, the hollow prefabricated reinforced concrete pipe is arranged below a freezing line, can reduce the temperature difference between the inside and the outside of the roadbed, reduces the freezing and thawing cycle damage to a certain extent due to the thermal bridge effect caused by temperature stress, is arranged above the freezing line, improves the internal structure of the roadbed, increases the transmission path of upper load, simultaneously reduces the generation of the thermal bridge effect, and relatively reduces the use of filling materials.
The structure for limiting the lateral displacement of the freeze-thaw roadbed provided by the utility model is suitable for construction and use on special roads in high sea and low temperature, has strong regionality, takes the damage of freeze-thaw cycles to the roadbed as a starting point, comprehensively utilizes the characteristics of pile arrangement, soil geogrids and prefabricated reinforced concrete pipe piles, and can effectively reduce the lateral deformation of the roadbed during the thawing period and improve the transmission path of road surface load through the composite roadbed formed by internal and external combination, so that the overall stability of the roadbed is improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.
Fig. 1 is a schematic diagram of a roadbed cross-sectional structure of a lateral displacement structure for limiting a freeze-thaw roadbed according to an embodiment of the utility model.
Fig. 2 is a schematic diagram of a double-row pile hole arrangement structure of a lateral displacement structure for limiting a freeze-thaw roadbed according to an embodiment of the utility model.
Fig. 3 is a schematic diagram of a roadbed longitudinal section structure of a lateral displacement structure for limiting a freeze-thaw roadbed according to an embodiment of the utility model.
Fig. 4 is a schematic representation of an above-ground cross-sectional configuration of a lateral displacement structure limiting a freeze-thaw subgrade, in accordance with an embodiment of the utility model.
Fig. 5 is a schematic view of a subsurface cross-sectional structure of a lateral displacement structure for limiting freeze-thaw subgrade according to an embodiment of the utility model.
Reference numerals:
1. arranging filling piles in a staggered manner; 2. a gravel soil layer; 3. a fine soil layer; 4. a geogrid; 5. a reinforced concrete pipe is prefabricated.
Detailed Description
The utility model is further described with reference to the following drawings and detailed description:
referring to fig. 1-5, the lateral displacement structure for limiting a freeze-thaw roadbed according to the embodiment of the utility model comprises staggered cast-in-place piles 1, gravel soil layers 2, fine soil layers 3, geogrids 4 and prefabricated reinforced concrete pipes 5, wherein the two sides of the freeze-thaw roadbed are respectively provided with row piles, the row piles comprise two groups of staggered cast-in-place piles 1 which are distributed in parallel and buried in the ground, the part above the ground of the freeze-thaw roadbed is provided with the gravel soil layers 2, the fine soil layers 3, the geogrids 4, the fine soil layers 3, the gravel soil layers 2, the fine soil layers 3, the geogrids 4, the fine soil layers 3 and the gravel soil layers 2 which are distributed in sequence from top to bottom, the prefabricated reinforced concrete pipes 5 are respectively laid in the first layer gravel soil layers 2 and the second layer gravel soil layers above the ground, and the part below the ground of the freeze-thaw roadbed is provided with the gravel soil layers 2, the prefabricated reinforced concrete pipes which are distributed in sequence from top to bottom, The soil engineering grating comprises a geogrid 4, a fine particle soil layer 3, a broken stone soil layer 2, a fine particle soil layer 3, the geogrid 4, the fine particle soil layer 3 and the broken stone soil layer 2, and prefabricated reinforced concrete pipes 5 are paved in the broken stone soil layers 2 of the first layer and the second layer below the ground.
The treatment of the high-cold frozen-melted roadbed is divided into two parts, namely a part below the ground and a part above the ground, and comprises the following steps:
the method comprises the following steps: geological exploration: and carrying out geological survey on the freeze-thaw roadbed to be filled, wherein a soft soil layer of the freeze-thaw roadbed is subjected to a conventional geotechnical test, the natural gravity, the natural water content, the specific gravity, the saturation, the cohesive force and the internal friction angle of the soil layer are measured, and the bearing capacity, the compression modulus and the like of the roadbed are determined by utilizing a standard penetration test, a load test and the like so as to obtain related basic physical and mechanical index parameters.
Step two: positioning and drilling: according to the detection and measurement results, the width ranges of two sides of the roadbed are determined, two rows of staggered pile holes are formed in the edge of the roadbed as shown in figure 2, the drilling depth of the rows of piles is determined, the two rows of staggered piles on the two sides are numbered, in order to prevent the hole wall from collapsing, a pile casing can be arranged on the hole position, then the hole is formed, the bottom is cleared, a reinforcement cage is arranged, concrete is poured, and the construction of the poured pile is completed.
Step three: the cement fly ash mixed slurry is prepared, and cement, sand, broken stone, fly ash and water in a certain proportion are stirred by a stirrer until a certain gelled state is formed.
Step four: and (3) pouring to form a pile, pumping the prepared cement fly ash slurry to the outer pipe of the pile pipe through a concrete pump, and pulling out the outer pipe after the cement fly ash slurry is poured, so as to pour the adjacent pile holes. And after pile forming, continuously utilizing the pile driver to pile the next row of staggered pile holes. The two sides of the roadbed can be processed simultaneously. In order to prevent collapse of the pile hole and reduce the influence on adjacent holes during the hole forming process, the hole forming sequence is as shown in fig. 3.
Step five: according to the geological survey report, determining a freezing size line of the freezing and thawing roadbed, excavating the freezing line to a soil layer in the earth surface area with an excavation slope ratio of 1:0.5, and conveying the excavated soil to a storage place.
Step six: and paving a broken stone soil layer 2 at the bottom of the excavated layer, paving a fine soil layer 3, paving a geogrid 4, covering the fine soil layer 3, paving the broken stone soil layer 2, and compacting by using a smooth-wheel road roller.
Step seven: after compaction, the coarse-grained soil surface is paved with prefabricated reinforced concrete pipes 5 according to a certain interval, the burying position is correspondingly marked, a gravel cushion layer is paved on the prefabricated reinforced concrete pipes, and repeated rolling is carried out.
And step eight, after repeating the step 6-7 for two times, laying the prefabricated reinforced concrete pipes 5 and the geogrids 4. When the prefabricated reinforced concrete pipes 5 of the upper layer are laid, the prefabricated reinforced concrete pipes of the upper layer and the prefabricated reinforced concrete pipes of the lower layer are arranged in a staggered mode according to the reserved laying positions of the prefabricated reinforced concrete pipes of the lower layer, and the prefabricated reinforced concrete pipes of the upper layer and the prefabricated reinforced concrete pipes of the lower layer are arranged in a triangular mode as shown in the figure 2. And after the second layer of prefabricated reinforced concrete pipes 5 are paved, continuously paving the gravel soil layer 2 in layers after the upper gravel cushion layer is paved, and compacting the gravel soil layer by layer until the ground height is reached.
Step nine: and (5) filling the roadbed above the ground. And (2) arranging the upper layer and the lower layer in a staggered manner according to the laying position of the reserved prefabricated reinforced concrete pipe 5 of the lower layer, then laying a gravel cushion layer, continuously laying gravel soil for compaction, then laying a fine-grained soil layer 3, laying a geogrid 4 on the fine-grained soil layer, laying a gravel soil layer 2 after covering the fine-grained soil layer, and compacting by using a smooth-wheel road roller.
Step ten: and continuously paving a broken stone soil layer 2, paving a fine soil layer 3 when the thickness reaches a certain design thickness, paving a geogrid 4 on the soil layer after compaction, paving coarse-grained soil after covering the geogrid with fine-grained soil, and compacting by using a smooth-wheel road roller.
Step eleven: and repeating the step ten, paving a layer of geogrid 4, and filling the geogrid to the designed height of the road surface by adopting a gravel soil layer 2.
Step twelve: and (6) treating the pavement.
Specifically, the external double-row piles actively press the roadbed to slow down lateral deformation of the foundation soil caused by pavement load and roadbed dead weight in the soil body thawing period of the roadbed.
Specifically, the overground part and the underground part inside the roadbed are alternately arranged by adopting reinforced concrete pipes and geogrids, so that the roadbed improves the transmission path of upper load while avoiding the generation of a heat bridge effect. In the soil body thawing period, the geogrids are alternately arranged, so that a filling body has certain pulling force, the overall stability of the roadbed is improved, the lateral deformation of the roadbed is limited from the inside, and the damage of freezing-thawing circulation in alpine regions to the roadbed is reduced.
Finally, it should be noted that: although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art will understand that various changes, modifications and substitutions can be made without departing from the spirit and scope of the utility model as defined by the appended claims. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (2)
1. A lateral displacement structure for limiting a freeze thawing roadbed is characterized by comprising staggered cast-in-place piles, broken stone soil layers, fine grain soil layers, geogrids and prefabricated reinforced concrete pipes, wherein the two sides of the freeze thawing roadbed are respectively provided with a row pile, the row piles comprise two groups of staggered cast-in-place piles which are distributed in parallel and buried in the ground, the broken stone soil layers, the fine grain soil layers, the geogrids, the fine grain soil layers and the broken stone soil layers are arranged above the ground of the freeze thawing roadbed in a distributed mode from top to bottom, the prefabricated reinforced concrete pipes are laid in the broken stone soil layers of a first layer and a second layer above the ground, the broken stone soil layers, the geogrids, the fine grain soil layers, the broken stone soil layers, the fine grain soil layers, the geogrids, the fine grain soil layers and the broken stone soil layers are arranged below the ground of the freeze thawing roadbed from top to bottom in a distributed mode, prefabricated reinforced concrete pipes are laid in the gravel soil layers of the first layer and the second layer below the ground.
2. The structure for limiting lateral displacement of a freeze-thaw roadbed according to claim 1, wherein the layers of the above-ground part of the freeze-thaw roadbed and the below-ground part of the freeze-thaw roadbed are pressed together by a roller compactor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122490616.XU CN216193712U (en) | 2021-10-14 | 2021-10-14 | Lateral displacement structure for limiting freeze thawing roadbed |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202122490616.XU CN216193712U (en) | 2021-10-14 | 2021-10-14 | Lateral displacement structure for limiting freeze thawing roadbed |
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| Publication Number | Publication Date |
|---|---|
| CN216193712U true CN216193712U (en) | 2022-04-05 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202122490616.XU Expired - Fee Related CN216193712U (en) | 2021-10-14 | 2021-10-14 | Lateral displacement structure for limiting freeze thawing roadbed |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216193712U (en) |
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2021
- 2021-10-14 CN CN202122490616.XU patent/CN216193712U/en not_active Expired - Fee Related
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