沉管隧道国产化GINA止水带试验研究及选型设计

Experimental Study and Selection Design of Domestic GINA Gasket for the Immersed Tunnel

  • 摘要: GINA止水带是沉管隧道的防水生命线。文章以襄阳汉江沉管隧道为背景,通过足尺物理模型试验对国产化GINA止水带在各不利工况下的压缩、水密性、应力松弛等性能开展研究,并结合试验数据进行选型设计。结果表明:(1)止水带压缩应力随时间增加而逐渐减小,并逐渐趋于稳定收敛,国产止水带产品100年平均应力松弛衰减率约为35%;(2)止水带压缩量随压缩力增大逐渐趋于止水带高度60%这一极限值,设计允许的接头偏转量将降低止水带压应力4.4%~9.2%;(3)国产止水带产品最小水密压缩量曲线趋势与某国外产品基本吻合,偏差量约0~15%;0.1°和0.22°接头偏转使所需最小水密压缩量略增;接头竖向错动1 cm,3 cm和5 cm,水平错动5 cm均未出现漏水,不影响止水带水密性能;(4)止水带设计需考虑正常使用和承载能力极限状态管节温差变化、混凝土干缩徐变、基础不均匀沉降、地震等引起的接头张合,需满足最小水密和最大压缩指标双控要求;(5)国产GINA止水带各项性能均可满足依托工程需求并具有一定安全余量。

     

    Abstract: GINA gasket is the waterproof lifeline of immersed tunnels. Based on the Hanjiang immersed tunnel in Xiangyang as the background, a full scale physical model test is conducted to study the compression, water tightness and stress relaxation of the domestic GINA gasket under various unfavorable conditions, and selection and design are carried out according to the test data. The research shows that: (1) compressive stress of the domestic GINA gasket gradually decreases with time and tends to stable converge, the 100-year average stress relaxation attenuation rate of domestic GINA gasket is about 35%; (2) with the increase of compression force, compression of GINA water stop tends to reach the limit value of its height by 60%, the allowable joint deflection will reduce the compressive stress of GINA water stop by 4.4%-9.2%; (3) the watertightness required minimum compression curve of domestic water stop is basically agree with that of a foreign product, with the deviation is about 0-15%; the watertightness required minimum compression increases slightly as for the joint with deflection angles of 0.1 and 0.22 degrees; in the case of vertical offset of joint by 1 cm, 3 cm, 5 cm and horizontal offset by 5 cm, no water leakage occurs and water tightness is not affected; (4) design of water stop should consider the joint opening and compression caused by the temperature change, concrete shrinkage and creep, uneven settlement of foundation, earthquake and so on under the normal and ultimate states of load capacity, and also meet the requirements for the minimum water tightness and the maximum compression; (5) performance of the domestic GINA water stop can meet the needs of the project and it has certain safety margin.

     

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