Backfilling of culvert abutment: a key link to ensure road stability and safety

Backfilling of culvert abutment is a key link to ensure road stability and safety. Let's take a look at this process and how to ensure the construction quality.

Digging and cleaning

First of all, the foundation pit behind the abutment must be completely excavated to the design requirements, and the sundries in the foundation pit must be thoroughly cleaned. According to the design requirements, it is also necessary to dig steps to ensure that the width of the steps is not less than 2 meters, and set an inward slope of 2%.

Backfill earthwork

With the cooperation of excavator and dump truck, the earthwork will be transported back to backfill. In order to ensure the degree of compaction, the backfill of abutment back should be carried out in layers, and the compaction thickness of each layer should not exceed 20 cm. For the convenience of control, we will draw 20 cm lines on the back of the platforms on both sides. Don't forget to coat the waterproof layer on the back of the table before drawing lines!

♂? Compaction and leveling

Each layer of backfill soil should be compacted, and 2%~4% cross slope should be set to facilitate drainage. The design width of each layer is 30 cm, which can ensure the compaction of the final embankment edge. Roughing by bulldozer first, and then finishing by hand to achieve the specified flatness.

submerge

Use vibratory roller for rolling. The first time is static pressure without vibration, and then gradually strengthen. Roller should overlap 0.4~0.5 meters for rolling, from both sides to the middle. For places that cannot be crushed by machinery (within the range of 0 ~ 2m at the back of abutment), we use flat vibrating rammer to tamp manually to ensure no pressure leakage and no dead angle.

quality assurance

In order to ensure the construction quality, we have taken the following measures: strictly implement the "three inspections" system; The construction of each layer of gravel must be approved by the supervisor; Backfill materials at abutment back must be sampled and tested to meet technical requirements; Soil containing humus, tree roots, etc. Should be removed from the backfill scope; The paving width of each layer of gravel soil should exceed 30 cm.