Informatics Publishing Limited

Yan Xu ¹, Lei Nie ¹, Min Zhang ¹, Tong Wang ¹, Jiaxin Wang ¹

Affiliations
1 College of Construction Engineering, Jilin University, CN

Abstract

The Chaancun debris flow gully is located on the mountain slope of the crown of the Chaancun landslide. The hiking corridor, leisure square, Lvshun middle road, and Wangjiadian reservoir are situated below the debris flow track. The Chaancun debris flow gully poses a serious threat to the safety of this site and to the development of tourist attractions. First, an appropriate recognition of the debris flow gully is required by a field investigation. This gully is steep and straight. The weathered and denuded rocks coming from the fault zone are the debris source. In addition, concentrated rainfall occurs in this area. Therefore, the debris flow gully has the forming conditions of a debris flow. Many factors affect the formation and assessment of a debris flow, and they result in uncertainty, randomness, and fuzziness. Therefore, the fuzzy mathematics method is suitable for the risk assessment of debris flow. To improve the reliability of the risk assessment of the Chaancun debris flow gully, primary fuzzy assessment and secondary fuzzy assessment considering hierarchical analysis were undertaken for quantitative risk assessment. This gully was categorized as "extremely hazardous;" thus, appropriate mitigations such as building a concrete dam and planting in bare areas were designed and implemented.

Keywords

Debris Flow, Risk Assessment, Fuzzy Mathematics, Mitigative Measures.

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Yanshun Zhao ¹, Peng Li ², Qilei Yin ¹, Tong Wang ³

Affiliations
1 College of Construction Engineering, Jilin University, Changchun 130026, CN
2 Xian Research Institute of China Coal Research Institute, Xian 710043, CN
3 Changchun Institute of Technology, Jilin University, Changchun 130021, CN

Abstract

This paper researches specialized reverse-circulation drilling bit for multi-layer goaf detection based on the multi-layer goaf detection project of iron ore mine in Yuan Village and designs a sliding-block reverse-circulation drilling bit with innovation, which is designed with large-through hole central channel, double-row inner orifice and sliding block. The structure of sliding block is used on reverse-circulation drilling bit for the first time. The performance of sliding-block reverse-circulation drilling bit is observed in practical drilling test, indicating good effect of reverse circulation, and high drilling efficiency, with the average drilling efficiency of 33.75m/h on extremely cracked land and 10.17m/h on hard land. The sliding-block reverse-circulation drilling bit can effectively solve the problem of blocking central channel since the structure of sliding block can meet the requirement on drilling. The top plate of multi-layer goaf can be drilled through successfully. C-ALS three-dimensional laser scanner can be put down through the central channel to solve the difficulty of simultaneous scan and detection on multi-layer goaf.

Keywords

Goaf, Pass-Through Down-Hole Hammer Reverse-Circulation Drilling Technology, C-ALS Three-Dimensional Laser Scanner, Sliding-Block Reverse-Circulation Drilling Bit.

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