— Compaction Hammer Construction Overview:
The Ramming Method is a technique that uses a ramming hammer to directly ram the steel pipes to be laid along the designed route into the ground, achieving non-excavation pipeline laying. The system includes auxiliary equipment such as an air compressor, ramming hammer, grab pressure plate, conical joint, spoil cone, tension band, and cutting pipe head.
The working principle of the pile driving method is that the pile hammer, driven by compressed air, generates a significant impact force directly acting on the rear end of the steel pipe, overcoming the friction between the soil layer and the pipe body. The front steel cutting pipe head cuts into the soil, and the cut soil core temporarily remains inside the steel pipe. After successful pile driving, the cutting pipe head is removed, and the soil core is then排出 by methods such as compressed air, high-pressure water jet, or spiral drill rods.
The pile driving method is highly adaptable to soil strata, usable in almost any soil except for large boulder beds and large stones. It can be constructed over shallow overburden layers, with a wide range of pipe diameters, simple equipment, low investment, easy operation and maintenance, and low construction costs. The construction accuracy is high, with horizontal and elevation deviations that can be controlled within a 2% range.
Due to the significant impact forces that piping must withstand, the pile driving method is limited to steel pipe construction, typically using seamless steel pipes with wall thicknesses meeting certain requirements, and pipe diameters ranging from 200 to 2000mm. The laying length is determined by the pile hammer's power, pipe diameter, and geological conditions, generally within 80m, with lengths up to 150m. This method is highly efficient, with construction speeds of 15-30m/h.
II. Construction Process
Section 3: Construction Techniques Key Points
(1) Site leveling: Choose a side with convenient transportation, flat terrain, and no obstructions to construct an access road.
(2)Measurement and Alignment: Based on design drawings and on-site stakes, lay out the center line of the crossing pipeline and position the embankment and reception pits, and drive control stakes. The centerline of the crossing pipeline should avoid underground electrical cables.
Obstructions such as vines, pipelines, etc.
(3) Excavation and Compaction Pits: Depending on the geological conditions and the varying groundwater levels, determine whether to lay a cement foundation at the bottom of the pit and the necessary dewatering measures to be taken. For geology prone to collapse, methods such as driving steel sheet piles or temporary supports should be employed to ensure construction safety within the operation pit. The layout of the compaction and receiving operation pits is illustrated in the following diagram.
(4) Construction Equipment and Casing Transportation: The main equipment for pile driving construction includes pile hammers, air compressors, generators, welders, etc.; the length of the casing transported to Yuncheng should be 2~3 meters longer than the designed length to cross obstacles.
