采用CFRP加固水工压力隧洞时,CFRP除了要承担变化的外部水土荷载,还要承担部分内水压力。为了明确“CFRP-胶层-衬砌混凝土”复合结构的内压分载规律,建立了“实体-弹簧-实体”三维有限元模型,并结合模型试验的实测结果验证了有限元模型的有效性。基于该模型,分析了胶层的弹性模量(Ea)、胶层的厚度(ta)、CFRP的弹性模量(Ec)和CFRP的厚度(tc)等参数变化时,衬砌混凝土和CFRP之间承担内水压力比例的变化规律。计算分析结果表明:tc和Ec是影响衬砌混凝土承担内水压力比例的主要因素。对于粘贴1~3层的计算工况,当tc由0.1 mm逐渐增加到2 mm的过程中,衬砌混凝土承担内水压力的比例分别减小了34.25%、47.776%、53.931%;当Ec由100 GPa增加到600 GPa的过程中,衬砌混凝土的承载比例分别减小了6.482%、11.945%、16.509%。极差分析结果也表明,衬砌混凝土承担内水压力的比例对上述4个参数的敏感性由高到低依次为tc＞Ec＞Ea＞ta。因此,若要降低衬砌混凝土承担内水压力的比例并提高CFRP材料的利用率,提高所选用的CFRP的厚度与弹性模量是关键。
Abstract
Carbon Fibre Reinforced Polymer (CFRP) bears not only the varying external soil and water loads, but also part of the internal water pressure when used in strengthening pressure tunnels. To investigate the joint bearing mechanism of the composite structure containing CFRP, adhesive lining, and concrete under internal water pressure, we established a “solid-spring-solid” 3D finite element model of pressurized water conveyance tunnel strengthened with CFRP, and verified the validity of the model via model test. By using this model, we examined the ratio of bearing internal water pressure between lining concrete and CFRP under varying conditions including elastic modulus of adhesive layer (Ea), thickness of adhesive layer (ta), elastic modulus of CFRP (Ec), and thickness of CFRP (tc). Results reveal that tc and Ec are dominant factors that affect the bearing ratio. In the presence of 1-3 layers of CFRP, with tc gradually increasing from 0.1 mm to 2 mm, the percentage of internal water pressure borne by lining concrete declined by 34.25%, 47.776%, and 53.931%, respectively; when Ec grew from 100 GPa to 600 GPa, that percentage dropped by 6.482%,11.945%,and 16.509%,respectively. Range analysis also manifest that the percentage of internal water pressure borne by lining concrete is most sensitive to tc,followed by Ec,Ea,and ta in descending order. In conclusion, improving the thickness and modulus of CFRP is the key to enhancing the utilization of CFRP and to reducing the percentage of internal water pressure borne by lining concrete.
关键词
压力隧洞 /
CFRP加固隧洞 /
复合结构 /
内压分载比例 /
参数分析
Key words
pressure tunnel /
tunnel strengthened with CFRP /
composite structure /
bearing ratio of internal water pressure /
parameter analysis
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参考文献
[1] 何 川,刘四进,张玉春,等.水下隧道衬砌结构服役安全及其保障对策思考[J].中国工程科学,2017,19(6):44-51.
[2] JIA Jin-sheng. A Technical Review of Hydro-Project Development in China[J]. Engineering, 2016, 2(3): 88-109.
[3] 张 奇. 输水隧洞盾构穿越轨道交通结构安全稳定分析研究[D]. 北京:清华大学, 2015.
[4] LIU De-jun, HUANG Hong-wei, YUE Qing-rui, et al. Behaviour of Tunnel Lining Strengthened by Textile-reinforced Concrete[J]. Structure and Infrastructure Engineering, 2016, 12(8): 964-976.
[5] 罗立娜.碳纤维补强条件下公路隧道衬砌计算方法的研究[D].上海:同济大学,2006.
[6] 何 川,唐志成,汪 波,等.内表面补强对缺陷病害隧道结构承载力影响的模型试验研究[J].岩土力学,2009,30(2):406-412.
[7] YUAN Hong, LI Fa-ping. Peeling Behavior and Spalling Resistance of CFRP Sheets Bonded to Bent Concrete Surfaces[J]. Acta Mechanica Sinica, 2010, 26: 257-264.
[8] CHEN Hai-long, XIE Wei, JIANG Mei-rong, et al. Blast-loaded Behaviors of Severely Damaged Buried Arch Repaired by Anchored CFRP Strips[J]. Composite Structures, 2015, 122: 92-103.
[9] WANG Peng, JIANG Mei-rong, ZHOU Jian-nan, et al. Spalling in Concrete Arches Subjected to Shock Wave and CFRP Strengthening Effect[J]. Tunnelling and Underground Space Technology, 2018, 74: 10-19.
[10] 杨成忠,黄 明,刘新荣,等. 碳纤维布用于深埋隧道衬砌裂缝的加固效果[J]. 解放军理工大学学报(自然科学版), 2010, 11(3): 322-327.
[11] 陈亚鹏,袁文阳. 纤维复合材料加固钢筋混凝土管三维有限元计算[J]. 中国农村水利水电, 2005(5): 54-56.
[12] 李宇杰,王梦恕,徐会杰,等.纤维布补强地铁隧道结构的数值分析[J].土木工程学报, 2014, 47(8): 138-144.
[13] 葛立福,薛桂玉,陈尚建. GFRP在水工涵管加固中的非线性有限元计算[J]. 中国农村水利水电,2005(6):61-63.
[14] 葛立福. 纤维复合材料加固水工涵管的有限元分析及应用[D]. 武汉:武汉大学, 2004.
[15] 王利阳.纤维材料加固钢筋混凝土压力管道的试验研究[D].武汉:武汉大学,2004.
[16] 刘 飞.地下管道灾后应急处置加固技术研究[D].大连:大连理工大学,2009.[17] 秦 敢,曹生荣,杨 帆.胶层对内贴CFRP加固圆形隧洞受力特性的影响[J].天津大学学报(自然科学与工程技术版),2019,52(1):62-70.
[18] DE LORENZIS L, ZAVARISE G. Interfacial Stress Analysis and Prediction of Debonding for a Thin Plate Bonded to a Curved Substrate[J]. International Journal of Non-linear Mechanics, 2009, 44(4): 358-370.
[19] LOPEZ-GONZALEZ J C, FERNANDEZ-GOMEZ J, GONZALEZ-VALLE E. Effect of Adhesive Thickness and Concrete Strength on FRP-concrete Bonds[J]. Journal of Composites for Construction, 2012, 16(6): 705-711.
[20] 钟正强,喻 奕,刘 波.胶层厚度对预应力CFRP加固混凝土梁粘结应力的影响试验[J]. 中国公路学报,2014,27(11):55-62.
[21] 贺学军.FRP加固负载混凝土梁的抗弯性能及剥离行为研究[D].长沙:中南大学,2007.
基金
国家重点研发计划项目(2019YFC0810702);中央高校基本科研业务费专项(JZ2020HGQA0141)
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