A foundation treatment structure for the new and old filling transition area of an airport pavement influence area

Abstract

A kind of ground treatment structure for the new and old filling interface area of airport pavement influence area belongs to ground structure technical field.The structure includes geogrid, over-excavation replacement layer, slope step, reinforcing step and filling layer, 2-4m over-excavation replacement layer is set on the top surface of original filling body, slope step is set on the slope of original filling body, the width of slope step is not less than 2m, one layer of reinforcing step is filled on the outside of every two slope steps, filling layer is filled outside reinforcing step again, the top of filling layer is filled to the same elevation as the top of over-excavation replacement layer, geogrid is laid on the interface of original filling body and filling layer top surface, the laying width of geogrid on filling layer and original filling body is 10-15m, and new pavement is built on the top surface of over-excavation replacement layer and filling layer.The structure improves the overall stability and reliability of new pavement foundation, reduces post-construction settlement and uneven settlement, and ensures the safety of upper pavement structure.

Description

Technical Field

[0001] This utility model belongs to the field of foundation structure technology, specifically relating to a foundation treatment structure for the junction area of ​​new and old fill in the impact zone of airport pavement. Background Technology

[0002] Airport expansion and renovation projects involving high fills face unique engineering challenges: constrained by airside planning, safety clearances, and land boundaries, flight zone expansion often requires overlapping fill construction on existing fill slopes. However, existing fill layers commonly suffer from insufficient compaction and weak bonding between new and old fill layers, leading to differential settlement in the pavement structure. This structural defect not only directly affects pavement smoothness and load transfer performance but also poses a potential threat to aircraft takeoff and landing safety, becoming a bottleneck restricting the quality of high fill airport expansion and renovation projects. Utility Model Content

[0003] This utility model proposes a foundation treatment structure for the junction area between new and old fill in the impact zone of airport pavement, which improves the overall stability and reliability of the pavement foundation, reduces post-construction settlement and uneven settlement, and ensures the safety of the upper pavement structure.

[0004] A foundation treatment structure for the junction area between old and new fill in the impact zone of airport pavement is characterized by comprising: geogrid, over-excavated replacement layer, slope steps, reinforcing steps, and fill layer. A 2-4m over-excavated replacement layer is set on the top surface of the original fill. Slope steps are excavated on the slope of the original fill, with a width of not less than 2m. A reinforcing step is filled on the outside of every two slope steps, and a fill layer is then filled on the outside of the reinforcing steps. The top of the fill layer is filled to the same elevation as the top of the over-excavated replacement layer. Geogrid is laid at the junction of the top surface of the original fill and the fill layer. The laying width of the geogrid in both the fill layer and the original fill is 10-15m. The new pavement is constructed on the top surface of the over-excavated replacement layer and the fill layer.

[0005] Furthermore, the geogrid is laid in two layers, with the bottom layer of geogrid compacted before the second layer of geogrid is laid.

[0006] The beneficial effects of this utility model are as follows: By setting up high slope steps and reinforcing steps, not only can the original fill be deeply reinforced, but the compaction quality of the original fill is also improved without extensive excavation and replacement work. This saves construction time, accelerates the construction progress of the fill layer, reduces post-construction settlement, and alleviates uneven settlement of the foundation. For the original fill located in the area affected by the new pavement, an over-excavation replacement layer is set up to ensure the foundation quality of the core area below the roadbed of the new pavement. Unlike the conventional practice of laying geogrid on the excavated step surface, this utility model lays multiple layers of geogrid at the junction of the old and new fill, ensuring a laying width of at least 10m on each side of the junction surface. This allows sufficient frictional force between the geogrid and the soil, fully utilizing the deformation coordination capacity of the geogrid reinforcement.

[0007] Through the combined effect of the above structures, the overall stability and reliability of the foundation of the newly built pavement are improved, post-construction settlement and uneven settlement are reduced, and the safety of the upper pavement structure is ensured. Attached Figure Description

[0008] Figure 1 This is a schematic diagram of a foundation treatment structure for the junction area between new and old fill in the airport pavement impact zone.

[0009] Among them: 1-Original fill, 2-Slope steps, 3-Reinforcing steps, 4-Fill layer, 5-Geogrid, 6-Over-excavated replacement layer, 7-New pavement. Detailed Implementation

[0010] Example 1: A foundation treatment structure for the transition area between old and new fill layers in the airport pavement impact zone. A new fill layer 4 is constructed on the basis of the original fill body 1, and a new pavement 7 is built. This structure includes a geogrid 5, an over-excavated replacement layer 6, slope steps 2, reinforcing steps 3, and the fill layer 4. The construction process of this structure is as follows:

[0011] S1. Demolish the original slope protection structure of the fill body 1, and excavate the slope steps 2 step by step from bottom to top. The width of the slope steps 2 is not less than 2m. During the excavation of the slope steps 2, reinforced steps 3 and fill layers 4 are constructed simultaneously on the outside of the slope steps 2. One layer of reinforced steps 3 is filled on the outside of every two slope steps 2. The reinforced steps 3 and fill layers 4 are compacted in layers. After the slope steps 2 are excavated, reinforced steps 3 and fill layers 4 are filled in a timely manner. Every 4m of fill layer 4 is filled upwards, the reinforced steps 3 and fill layers 4 at the same elevation are subjected to overall dynamic compaction reinforcement construction. The dynamic compaction energy level is 3000-4000kN·m, and the depth of influence of the reinforcement effect is 4-5m, which reinforces the original fill body 1 and reduces the post-construction settlement of fill layer 4.

[0012] S2, on the top of the original fill 1, based on the top elevation of the new pavement 7, excavate a 2-4m over-excavated replacement layer 6 downwards to replace the original fill with insufficient compaction in the core area below the top surface of the new pavement 7, thereby improving the quality of the foundation structure of the new pavement 7.

[0013] After the top of the fill layer 4 and the bottom of the over-excavated replacement layer 6 are constructed to the same elevation, the original fill body 1 and fill layer 4 are reinforced by overall dynamic compaction with a dynamic compaction energy of 3000-4000 kN·m to improve the overall stability of the combined foundation of the new original fill body 1 and fill layer 4.

[0014] S4. At the junction of the original fill body 1 and the top surface of the filling layer 4, geogrid 5 is laid. The laying width of geogrid 5 in both the filling layer 4 and the original fill body 1 is 10-15m. After compacting the bottom layer of geogrid 5, the second layer of geogrid 5 is laid to give full play to the deformation coordination function of the geogrid and improve the overall stability of the foundation.

[0015] S5, continue filling the fill layer 4 to the base elevation of the new pavement 7, and fill the over-excavated replacement layer 6 to the base elevation of the new pavement 7, and finally construct the new pavement 7 on top of the two.

Claims

1. A foundation treatment structure for the transition area between old and new fill in the airport pavement impact zone, characterized in that: The project includes geogrid, over-excavated replacement layer, slope steps, reinforcing steps, and fill layer. A 2-4m over-excavated replacement layer is set on the top surface of the original fill body. Slope steps are excavated on the slope of the original fill body, with a slope step width of not less than 2m. A reinforcing step is filled on the outside of every two slope steps. A fill layer is then filled on the outside of the reinforcing steps. The top of the fill layer is filled to the same elevation as the top of the over-excavated replacement layer. Geogrid is laid at the junction of the top surface of the original fill body and the fill layer. The laying width of the geogrid in both the fill layer and the original fill body is 10-15m. The new pavement is constructed on the top surface of the over-excavated replacement layer and the fill layer.

2. The foundation treatment structure for the transition area between old and new fill in the airport pavement impact zone as described in claim 1, characterized in that... The geogrid is laid in two layers, with the bottom layer compacted before the second layer is laid.

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