Vertical drilling rig quality appraisal

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shaft drilling rig is based on the core principle of full-section drilling and multi-level support. By optimizing the power head torque, drilling verticality and drill pipe fatigue strength, it can achieve efficient hole formation, shaft wall stability and construction safety of large-diameter shafts. It is widely used in mining shafts, underground storages, subway ventilation shafts and hydropower projects. In deep mines, it is used for one-time drilling of thousand-meter shafts; in the construction of shield launch shafts, it meets the needs of rapid drilling of high-strength rock formations; in the field of nuclear waste disposal, it ensures the integrity of geological barriers. Compared with traditional drilling equipment, shaft drilling rigs have the characteristics of modular expansion, intelligent monitoring, and wide stratum adaptability (hard rock to loose strata). They are the core equipment of deep earth engineering.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide shaft drilling rig quality appraisal services. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for shaft drilling rig quality appraisal.

As the complexity of deep underground engineering projects increases, related quality dispute cases have increased significantly. The judicial dispute focuses on:

1, performance index dispute: drilling speed does not meet the standard, wellbore deflection exceeds the standard;

2, material defects: insufficient fatigue life of the drill pipe joint, insufficient surface hardness of the power head gear ;

3, process problems: hydraulic system pressure fluctuations, guide system correction delays;

4, contract performance disputes: key modules (such as variable frequency motor power, automatic rod changing mechanism) are inconsistent with the technical agreement.

0 Such cases need to pass drilling parameter verification, material failure analysis and dynamic performance testing to clarify the quality responsibility.

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Shaft drilling rig quality appraisal technical methods mainly include:

Appearance inspection: Check whether the outer dimensions, surface flatness, paint coating, etc. of the precision shearing machine meet the standard requirements.

Geometric accuracy inspection: Check the shearing machine's tool angle accuracy, platen parallelism, relative position of the upper and lower tool rests and other geometric dimensional accuracy.

Cutting performance test: Use standard specimens to conduct shear tests to evaluate the cutting quality, shearing force and other performance indicators of the precision shearing machine.

Durability test: Conduct long-term continuous shearing operation on a precision shearing machine to evaluate its durability and reliability.

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A mining group of the applicant signed a "Φ10m shaft drilling rig purchase contract" with an equipment manufacturer of the respondent, agreeing that the drilling speed is ≥1.2m/h. The construction period was delayed due to inefficiency, and the manufacturer argued that it was caused by the development of cracks in the rock formations.

identification analysis results:

quality analysis expert group's relevant information on "shaft drilling rig", contract technical agreement, on-site investigation case materials and other data Discussion and comprehensive technical analysis were conducted, and the following quality analysis opinions were made:

The actual output torque of the power head of the shaft drilling rig involved in the case was only 380kN·m (agreement ≥500kN·m), and the heat treatment hardness of the drill pipe joint was HRC 50 (agreement ≥ 55); the guidance system’s deviation correction delay is 8 seconds (agreement ≤ 5 seconds), resulting in a deflection of 0.25%.

The appraisal conclusion determined that defects in the equipment’s power system and materials were the main causes of insufficient efficiency.

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Shaft drilling rig quality appraisal report should include:

1, purpose of appraisal (such as attribution of construction delays, safety compliance verification) and cited standards;

2, equipment model involved, design parameters, construction logs;

3, testing methods and equipment list (such as Torque tester, laser gyroscope);

4, analysis of the correlation between test data and failure (such as the impact of insufficient torque on drilling speed);

05, clarify the quality responsibility judgment conclusion and technical basis;

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26, signature of the appraiser, geotechnical engineer qualification certificate and official seal of the organization.

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