Pile Foundation for Old Urban Area Renovation: Construction Solutions for Rotary Drilling Rigs in Constrained Spaces

    The renovation of old urban areas often faces challenges such as narrow working surfaces, dense adjacent buildings, complex underground pipelines, and limited clearance. Rotary drilling rigs need to be adapted to equipment, optimized in process, and controlled on-site to achieve safe and efficient drilling.

    Before construction, site investigation and pipeline detection should be carried out to clarify the boundaries of existing buildings, pipelines, and roads. Reasonable planning of pile positions and drilling rig routes should be carried out to reduce site occupation and repeated displacement. The soft foundation is reinforced by laying steel plates and pouring temporary concrete cushion layers to ensure the stability of the drilling rig station.

    Priority should be given to selecting small-sized, low clearance modified rotary drilling rigs for equipment selection, controlling the width and operating radius of the machine body, and adapting to narrow passages and confined spaces; Choose a retractable short mast and a machine locked short drill rod to meet the requirements of low space operations, while ensuring the depth and verticality of the borehole. The drill bit is flexibly configured according to the formation, with a sand scoop for soil layers and a toothed cylinder for pebbles and rock layers, improving drilling efficiency and reducing the risk of hole wall collapse.

    The drilling operation adopts a segmented slow speed and light pressure slow rotation control method to reduce disturbance to the surrounding soil and buildings. Strictly control the mud indicators, do a good job in protecting the hole wall, and prevent shrinkage and collapse of the hole. The steel cage is made and lifted in sections, and is lowered and docked in a small space with the help of a small tonnage crane to ensure installation accuracy.

    Implement zone based flow operation on site, optimize the layout of slag transportation and material stacking, and avoid cross interference. Take noise reduction and dust reduction measures during construction to minimize the impact on residents' daily lives. Monitor the surrounding buildings and surface subsidence throughout the entire process, adjust parameters promptly in case of abnormalities, and ensure construction safety and stability of the surrounding environment.

    Through equipment adaptation, precise construction, and full process control, rotary drilling rigs can complete pile foundation operations in narrow spaces in old urban areas, meeting the quality, safety, and schedule requirements of renovation projects.