丹江口大坝加高工程坝踵应力的研究.docVIP

丹江口大坝加高工程坝踵应力的研究 　　摘要：通过数值模拟分析，以丹江口大坝加高前设计蓄水位157 m时，在坝体自重、上游水压力及相应水位下的扬压力等荷载作用下的坝体应力作为“初始应力状态”，分析加高后的坝踵应力是否恶化以及提高施工期水位对加高后坝踵应力的影响程度。分析认为：与“初始应力状态”相比，加高后当库水位升至校核洪水位174.6 m时，各坝段坝踵应力出现不同程度的恶化。提高施工期水位，对深孔坝段和厂房坝段的坝踵应力(库水位提高到正常蓄水位170 m及以上时)没有明显的不利影响，对左联35号坝和右联7号坝段的坝踵应力稍有不利影响。 　　关键词：丹江口大坝；加高工程；坝踵应力；施工期水位 　　中图分类号：TV331；TV642.3 　　文献标识码：A 　　文章编号：1672-1683(2008)02-0008-03 　　Study on Heel Stress of the Heightening Project of Danjiangkou Dam 　　XU Yue-zhi，SHAN Liang，XIAO Han-jiang 　　(Scientific Research Institute of the Yangtze River， Wuhan 430010，China) 　　Abstract：Through numerical value simulation and on the basis of the “initial stress state” under the pressure of the dam and the water of upper reaches and the uplift stress at the corresponding water level (The designed water storage level before heightening of the Danjiangkou Reservoir is 157m.)， the paper analyzes the heel stress of the dam after heightening and the effect to the heel stress after heightening by increasing the water level during the construction period. Compared with the initial stress state， as the water level of the dam after heightening increases to 174.6m (check flood level)， the heel stress of each section of the dam is worsened. According to the analysis， raising water level in the construction period has no obvious negative impact to the heel stress of the deep hole dam section and the factory building dam section (when the water level of the dam is increased to ≥170m) but slight negative impact to the heel stress of No.35 dam section at the left and No.7 dam section at right. 　　Key words：Danjiangkou Dam；heightening project；heel stress of dam；water level in construction period 　　 　　1 研究背景 　　 　　丹江口大坝加高工程是为了抬高水位，以满足南水北调的目的。加高工程将使大坝坝顶高程由162 m提高到176.6 m，正常蓄水位由157 m提高到170 m，校核洪水位由161.4 m提高到174.6 m。大坝加高后，最为关心的问题是坝踵应力是否恶化，这关系到大坝的安全稳定运行。影响坝踵应力的因素很多，如：水位抬高后，上游水压力增加，扬压力增大，不利于坝踵应力；大坝加高工程需要对大坝作加厚处理，加厚部分的温降同样不利于坝踵应力[1]；地基与坝体弹模比对坝踵主拉应力区也有一定影响，弹模比越大，坝踵单元具有较大的主拉应力，主拉应力区范围也大[2]。丹江口水利枢纽有多种坝型，如左、右联坝段、深孔坝段