| 隧道仰拱及基底能量桩热致应力与换热效率现场试验 |
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| 引用本文： | 于 达1,孔纲强1,季伟伟1,王成龙2,王忠涛3,杨 庆3. 隧道仰拱及基底能量桩热致应力与换热效率现场试验[J]. 建筑科学与工程学报, 2023, 0(3): 121-129. DOI: 10.19815/j.jace.2022.03047 |
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| 作者姓名： | 于 达1 孔纲强1 季伟伟1 王成龙2 王忠涛3 杨 庆3 |
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| 作者单位： | (1. 河海大学 岩土力学与堤坝工程教育部重点实验室,江苏 南京 210024; 2. 重庆大学 山地城镇建设与新技术教育部重点实验室,重庆 400045; 3. 大连理工大学 海岸和近海工程国家重点实验室,辽宁 大连 116024) |
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| 摘 要： | 依托黄土塬区银川—西安高铁驿马一号隧道工程,在隧道仰拱和基底桩基内埋设换热管,搭建能源隧道仰拱-基底能量桩联合热泵系统,实测不同进口温度作用下换热管的进出口水温、隧道仰拱结构和基底桩基的温度、热致应力,探讨黄土塬区隧道仰拱结构及基底桩基的换热效率、热力响应特性与变化规律。结果表明:在现场特定条件下,进口温度与初始地温差值分别为4.7 ℃和14.7 ℃时,隧道仰拱结构温度升幅分别约为3.8 ℃和11.4 ℃,热致轴向应力分别为3.13 MPa和13.86 MPa,热致环向应力分别为2.85 MPa和9.93 MPa,隧道仰拱换热效率分别约为7.86 W?m-1和24.15 W?m-1; 单位温升条件下热致轴向应力和热致环向应力分别为0.44 MPa?℃-1和0.35 MPa?℃-1; 恒功率运行下仰拱基底能量桩换热效率随进口温度与初始地温差值的变化近乎为一条斜率k=4.1过原点的直线,换热效率维持在50～70 W?m-1之间,与常规能量桩的换热效率规律基本一致; 桩基周围土体的力学性质受能量桩运行影响有限。
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| 关 键 词： | 隧道仰拱 桩基 黄土塬区 热致应力 换热效率 现场试验 |
Field tests on thermal induced stress and heat transfer efficiency of tunnel invert and base energy pile |
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| YU Da1,KONG Gangqiang1,JI Weiwei1,WANG Chenglong2,WANG Zhongtao3,YANG Qing3. Field tests on thermal induced stress and heat transfer efficiency of tunnel invert and base energy pile[J]. Journal of Architecture and Civil Engineering, 2023, 0(3): 121-129. DOI: 10.19815/j.jace.2022.03047 |
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| Authors: | YU Da1 KONG Gangqiang1 JI Weiwei1 WANG Chenglong2 WANG Zhongtao3 YANG Qing3 |
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| Affiliation: | (1.Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, Hohai University, Nanjing 210024, Jiangsu, China; 2.Key Laboratory of New Technology for Construction of Cities in Mountain Area, Chongqing University, Chongqing 400045, China; 3.State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, Liaoning, China) |
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| Abstract: | Based on Yima No.1 tunnel project of Yinchuan-Xi'an high-speed railway located in loess plateau, heat exchange tubes were buried in the tunnel invert and pile foundation, and energy tunnel invert-pile foundation combined heat pump system was built. The inlet and outlet water temperature, tunnel invert and pile foundation temperatures, thermal induced stress under difference inlet water temperature were measured. The heat transfer efficiency, the thermal response characteristics and change law of the tunnel invert and the soil surrounding energy pile were discussed and analyzed. The results show that in specific conditions on site, when inlet temperature and initial ground temperature difference are 4.7 ℃ and 14.7 ℃, respectively, the temperature of the tunnel invert structure rise about 3.8 ℃ and 11.4 ℃, the thermal induced axial stress are 3.13 MPa and 13.86 MPa, the thermal induced hoop stress are 2.85 MPa and 9.93 MPa, and the heat transfer efficiency of tunnel invert are 7.86 W?m-1 and 24.15 W?m-1. The unit thermal induced axial and hoop stress equal 0.44 MPa?℃-1 and 0.35 MPa?℃-1, respectively. Under constant power operation, the change of heat transfer efficiency of invert base energy pile with inlet temperature and initial ground temperature difference is almost a straight line with slope k=4.1 passing through the origin. The heat transfer efficiency maintained between 50-70 W?m-1, which is similar with that of conventional energy pile. The mechanical properties of the soil around the pile foundation are limited by the operation of the energy pile. |
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| Keywords: | tunnel invert pile foundation loess area thermal induced stress heat transfer efficiency field test |
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