Foundation dynamic compaction and replacement combined dynamic compaction reinforced construction method

Abstract

The invention relates to a foundation treatment method, in particular to a foundation dynamic compaction and replacement combined dynamic compaction reinforced construction method. The method comprises the steps that a construction area is dug, wherein at the bottom elevation of -0.9 m of a box culvert foundation, and aiming at improving the bearing force of a foundation obtained after box culvert foundation dynamic compaction treatment, the original ground is dug for 2.5 m, and then construction of dynamic compaction is started; sloping is carried out on the gradients of the two sides of a foundation trench according to the proportion of 1:1.5; according to the geologic features of a backfill sand land area of an iron and steel base, a 4,000KN.m dynamic compaction and replacement process is adopted for reinforcing a deep soil layer of 3 m to 9 m, and the foundation bearing force of the deep soil layer is improved; after dynamic compaction and replacement are completed, 3,000KN.m dynamic compaction is used for reinforcement, a deep soil layer of 0-6 m is reinforced, the foundation bearing force of the shallow soil layer is improved, the strength of a substratum soil layer of 0-2.3 m on the bottom face of a box culvert is improved, and therefore soil is reinforced in the vertical direction; flower arrangement is adopted in pile point arrangement, that is, dynamic compaction reinforcement is carried out between compaction points obtained after dynamic compaction and replacement, soil between piles is transversely compact, and therefore the foundation bearing force of the soil between the piles is improved, and the soil is reinforced in the transverse direction. As for large-area foundation treatment, construction speed is high, and limitation is small.

Description

technical field [0001] The present invention relates to a ground treatment method, in particular to a combined ground treatment method. Background technique [0002] With the rapid development of coastal city construction, more and more land is reclaimed from the sea, and it is formed by reclamation or sand blowing reclamation, enclosing and leveling, so most of the foundations of construction sites are met and needed Solve the problems of under-compactness, uneven settlement and low overall bearing capacity of large-area (unfinished self-weight consolidation) newly filled foundations, and most of the original ground foundations have silt and silt mixed in the bays, trenches, ponds and other terrains Highly compressible weak soils such as sand and silty clay need special treatment to improve the bearing capacity of composite foundations to meet the needs of various types of building (structure) foundations. The soil and the soft soil at the bottom ("loose at the top and sof...

AI Technical Summary

Problems solved by technology

[0003] At present, the common methods of foundation treatment are: A. Composite foundation method: cement-soil mixing pile, powder spray pile, gravel pile, etc.; advantages: high bearing capacity, small deformation, fast stability; disadvantages: high cost; B, drainage consolidation Method: vacuum or surcharge preloading, etc.; advantages: mature technology, combined with vertical drainage technology can handle foundations of different depths; disadvantages: long construction period

In addition, the formation of holes will be greatly affected by the groundwater level and soil quality, and the adjacent holes will collapse and deform during the pile formation process of dynamic compaction.

Theoretically, it is widely applicable, but the actual construction will be restricted by many factors. The potential energy in the dynamic compaction is used to complete the pile. The soil within a certain depth range of the surface layer will be loose due to the extrusion, so it must be reinforced