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  1. Article: Strengthening Device for Improving Shear Performance of Anchor Cable in Rock Support.

    Feng, Chao / Liu, Shaowei / Jia, Housheng / Fu, Mengxiong / He, Deyin

    Materials (Basel, Switzerland)

    2023  Volume 17, Issue 1

    Abstract: Many designs of anchor cables are currently in use for rock support in civil and mining operations. Because of the exposed surface and weak shear performance of the cable bolt's free section (CBFS) in end-anchored structures, breaking failure frequently ... ...

    Abstract Many designs of anchor cables are currently in use for rock support in civil and mining operations. Because of the exposed surface and weak shear performance of the cable bolt's free section (CBFS) in end-anchored structures, breaking failure frequently occurs. Numerical simulations and laboratory experiments were performed in this study to develop measures to improve CBFS resistance to shear failure. Analysis of shear characteristics of the CBFS showed that higher axial tension weakens the cable bolt's shear resistance, and that shear damage on the cable surface and uneven distribution of shear stress aggravate CBFS tensile-shear failure. A high-strength steel pipe is proposed to protect the shear cable bolt, and the preliminary design of a CBFS-strengthening device (CFSD) is presented. Numerical simulation revealed that the CFSD effectively improved CBFS shear resistance and provided protection from harmful shear damage. The optimal performance of a Q-type (slotted steel pipe) CFSD was confirmed. The mechanism of improvement of the cable's shear resistance to surrounding rock by employing the CFSD was analyzed. Double-shear tests were carried out on a bare cable bolt and a cable bolt with a Q-CFSD. The results revealed that the CFSD increased the peak shear force on the joint plane, cable peak axial force, and ultimate shear displacement by 31%, 18%, and 11%, respectively. The proposed device is effective in improving the shear performance of end-anchored cable bolts and enhancing surrounding rock stability.
    Language English
    Publishing date 2023-12-29
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2487261-1
    ISSN 1996-1944
    ISSN 1996-1944
    DOI 10.3390/ma17010197
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Thermal power extraction from a deep, closed-loop, multi-level, multi-branch, U-shaped borehole heat exchanger geothermal system

    Wang, Guoying / Ma, Hongwei / Liu, Shaowei / Yang, Dong / Xu, Xiaokai / Fu, Mengxiong / Jia, Housheng

    Renewable energy. 2022 Aug. 21,

    2022  

    Abstract: A novel closed-loop, multi-level, multi-branch, U-shaped borehole heat exchanger geothermal system is proposed to achieve a more efficient method to exploit deep geothermal resources. Compared with single U-shaped closed-loop geothermal systems, the new ... ...

    Abstract A novel closed-loop, multi-level, multi-branch, U-shaped borehole heat exchanger geothermal system is proposed to achieve a more efficient method to exploit deep geothermal resources. Compared with single U-shaped closed-loop geothermal systems, the new system can reduce the drilling cost and increase the heating length. In this study, first, a three-dimensional unsteady-state flow and heat transfer model was established. Then, the temperature distribution of the working fluid in the tube and a hot dry rock reservoir was analyzed. Third, the key factors that influence heat production were analyzed. The results show that increasing the injection rate blindly does not improve the heat production power; the maximum heat production power can only be obtained by controlling the injection rate to a certain extent. The heat production power has a good linear relationship with reservoir temperature and horizontal well length. Under different reservoir temperatures, the unit power generation price of the proposed geothermal system reaches the lowest value when the horizontal well length is 3000 m and the horizontal well branches number is 4. Overall, this novel design can improve the heat exchange efficiency, reduce the power generation cost and can serve as a reference for the study of exploiting deep geothermal resources.
    Keywords heat exchangers ; heat production ; heat transfer ; horizontal wells ; models ; power generation ; prices ; renewable energy sources ; temperature
    Language English
    Dates of publication 2022-0821
    Publishing place Elsevier Ltd
    Document type Article
    Note Pre-press version
    ZDB-ID 2001449-1
    ISSN 1879-0682 ; 0960-1481
    ISSN (online) 1879-0682
    ISSN 0960-1481
    DOI 10.1016/j.renene.2022.08.106
    Database NAL-Catalogue (AGRICOLA)

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  3. Article ; Online: Permeability enhancement mechanism of sand‐carrying hydraulic fracturing in deep mining

    Yin Shuaifeng / Ma Haifeng / Cheng Zhiheng / Zou Quanle / Li Yingming / Jia Housheng / Zhang Kexue

    Energy Science & Engineering, Vol 7, Iss 5, Pp 1867-

    A case study of uncovering coal in cross‐cut

    2019  Volume 1881

    Abstract: Abstract Coal and gas outburst disasters are prone to occur within rock cross‐cut coal uncovering in deep underground coal mines. To reduce the risk of coal and gas burst under rock cross‐cut coal uncovering, a technique of permeability enhancement using ...

    Abstract Abstract Coal and gas outburst disasters are prone to occur within rock cross‐cut coal uncovering in deep underground coal mines. To reduce the risk of coal and gas burst under rock cross‐cut coal uncovering, a technique of permeability enhancement using hydraulic fracturing sand‐carrying is proposed. Field test was conducted using HF sand‐carrying approach, and the effect of permeability enhancement was investigated. The results show that the evolution of cracks has been subjected three stages: energy slowly increasing and crack initiation, damage localization of coal seam and gradually failure, and crack instability expansion and formation of a complex fracture network system. In addition, it is found that “water‐sand” type injection of high‐pressure fluid carried sand into HF cracks, which creates a support force on crack surface and prevents crack closure. A fully developed fracture network system with high flow conductivity capacity is created and thus increases gas permeability largely. Furthermore, a clearly increasing trend associated with the HF sand‐carrying is found for the treated coal seam area. The permeability coefficient is about 21.5‐30.5 times higher than that from the raw coal seam. A good prevention effect of coal and gas outburst is achieved using HF sand‐carrying method.
    Keywords coal and gas outburst ; deep mining ; hydraulic fracturing ; permeability enhancement ; uncovering coal ; Technology ; T ; Science ; Q
    Subject code 669 ; 670
    Language English
    Publishing date 2019-10-01T00:00:00Z
    Publisher Wiley
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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