Rotary drilling rig is a kind of construction machinery suitable for hole-forming operations in building foundation projects. It is widely used in municipal construction, highway bridges, high-rise buildings and other foundation construction projects. With different drilling tools, it is suitable for dry type (short screw), or For hole forming operations of wet type (rotary bucket) and rock formation (core drilling), the rotary drilling rig has the characteristics of large installed power, large output torque, large axial pressure, flexible maneuverability, high construction efficiency and multi-function. The rotary drilling rig is suitable for the soil geological conditions in most parts of my country, and has a wide range of use, which can basically meet the use of bridge construction, high-rise building foundation and other projects. At present, rotary drilling rigs have been widely used in various bored pile projects. Therefore, it is of great significance to technically discuss the construction preparation of the rotary drilling rig and the common clear water construction technology.

1 Rotary drilling rig. Construction preparation

1. Data preparation

(1) Before starting construction, site engineering geological data and necessary hydrogeological data, as well as construction drawings and pile foundation engineering drawings should be prepared.

(2) Measurement data of underground pipelines (pipes, cables), underground structures, dangerous buildings, precision instrument workshops, etc. on site and in adjacent areas.

(3) Entrust the technical performance data of the main construction machinery and its supporting equipment, the inspection and mixing ratio test of the required materials, the physical property test of the required materials, and the qualified laboratory to conduct the test in accordance with the regulations. raw materials used. Good concrete mix test.

(4) Have an effective construction organization design or construction plan for the pile foundation project, and test reference materials related to loads and construction techniques.
 

Trial drawings

Make detailed safety technical disclosures, fully promote democracy before construction, mobilize the enthusiasm and creativity of employees, make all employees involved in the construction participate in the discussion of the construction plan, increase the emphasis on safety production quality assurance, and conduct evaluations for various departments.

2. Construction machinery and equipment

The measuring instruments used, such as theodolites, levels, steel tapes, rotary drilling machines, electric welding machines and other mechanical equipment must have factory certificates.

3. Installation of drilling tools for rotary drilling rigs

The drilling tool has a certain rigidity, and does not move and shake during drilling or other operations. The installation of the drilling tool should meet the manufacturer's standard. During construction, it can be equipped with various specifications of drill bits such as short auger bits, rotary buckets, core bits, and core rotary bits. During construction, according to different soil and geological conditions, choose different drill bits of the rotary drilling machine according to the following regulations: short auger drills, suitable for clay soil, silt soil, filling soil above the groundwater level, and sandy soil above medium density , weathered rock formations. Spiral rotary head, with mud wall protection, is suitable for clay soil, silt soil, sandy soil, filling soil, gravel soil and weathered rock formation above the groundwater level. Core auger bits for gravel soils, medium-hard rock and weathered rock formations. Core bit for weathered rock formations and cracked rocks. The specifications of the drill bits are selected and selected by the user according to the actual project conditions.