Preliminary commissioning of rapid impact compactor

As a technical means of filling special subgrade such as abutment subgrade, combined with the actual situation of the construction site, the rapid impact compaction can be used to strengthen the compactness of the subgrade at the bridge head and link the subgrade settlement phenomenon in the project applicable to the compactor, so as to effectively deal with the problem of vehicle jumping at the bridge head and ensure the safety of traffic.

For the abutment back Subgrade of Expressway channel, the role and related problems in the compaction process of abutment back subgrade are analyzed by means of research on its construction data, filler test and field compaction test. Now the conclusions are described as follows.

(1) after the abutment back subgrade is reinforced by rapid impact compactor, the compaction degree of abutment back subgrade filling can be strengthened and the subgrade settlement can be alleviated. The tensile strain of abutment back concrete is much lower than its limit value, which belongs to the technical means of effective treatment of abutment back subgrade. The construction technology proposed in the test is feasible, and the selected filler is consistent with the construction project.

(2) The maximum dynamic stress caused by rapid impact compactor operation on the subgrade is related to factors such as tamping potential energy, tamping subgrade height and subgrade modulus, and tamping potential energy has the greatest effect on the maximum dynamic stress. The dynamic stress caused by the tamping machine on the subgrade is positively correlated with the tamping times of the rapid impact compactor, the height of the tamping subgrade and the tamping potential energy, that is, the value of the dynamic stress will increase with the increase of the other three factors.

(3) The vertical dynamic stress produced by the rapid impact compactor will rapidly decrease with the deepening of the depth of the subgrade filling soil. The influence depth of the dynamic stress on the subgrade filling soil is about 200m, and the horizontal force caused by the dynamic stress of the compactor at the depth of 200m is about 100m.

(4) the subgrade settlement is directly proportional to the compaction times of the compactor, and the growth rate of the settlement will continue to slow down with the increase of the compaction times. At the same time, the settlement will continue to decrease with the deepening of the depth. When the depth of the filled soil exceeds 100m, there will be basically no deformation.