谈谈“块体容许失稳率”

Talk about "allowable ratio of instability of block"

文章对防波堤和护岸等港口工程中经常用到的专业术语——"块体容许失稳率"提出了质疑,指出其在应用过程中,主要依靠物理模型试验来获得,但是由于定义不严密,在模型试验时,特别是3D整体稳定性模型试验时,无法得到正确、合理的失稳率标准值。因此,难以判断防波堤和护岸工程设计的优劣,也不能指导设计方案的优化,将直接影响工程的安全可靠、经济合理。针对这一弊端,提出了建议:(1)保留和继续使用"块体容许失稳率"的有关规定,但是要在"块体容许失稳率"定义前面加上防波堤或护岸长度的限定;(2)废止和停止使用"块体容许失稳率"的有关规定,从严掌握防波堤和护岸的失稳标准;(3)在防波堤和护岸3D稳定性模型试验中,明确规定必须分段进行观测,应逐段分别给出稳定性的试验结果。这些建议,可供有关技术标准修订时参考。

In this paper, the professional term ＂allowable ratio of instability of block＂ used in breakwaters andshore protection was questioned. It was pointed out that in its application process, it was mainly depended on thephysical model test. But because of the low strictness of definition, the correct and reasonable standard value of instability rate could not be obtained in model test, especially 3D overall stability model test. Therefore, it is difficultto judge the breakwater and shore protection engineering design quality, and also cannot guide the optimization design scheme. It will directly affect the safe and reliable, economic and reasonable engineering. Aiming at the short-comings, the following suggestions were put forward：（1） adding length limit to breakwaters or shore protection in usage of the relevant regulations of ＂allowable ratio of instability of block＂;（2） abolishing and stopping usage of relevant regulations of ＂allowable ratio of instability of block＂, strictly controlling the instability standard of breakwaterand shore protection;（3） in 3D stability model test of breakwater and shore protection, observation must be segmented, and the stability test results should be given piecewise. The suggestions can be provided to related technicalstandard as a reference for revision.