岩层真厚度计算公式述评：兼与佟再三,佟洁,许边远同志商榷

从列昂托夫斯基的三个传统公式到沈忠悦的一个通用公式,使岩层真厚度计算简便得多。但沈氏公式中带有绝对值,所以当连续测量地层剖面而进行厚度累计时容易出错。虽然文朴、徐开礼讨论了负厚度问题,但仍需人工选择不同公式计算或判断正负号,甚至出现文中规定的正负号变换原则与实际情况相矛盾的情形。由此可见,岩层真厚度计算的关键问题乃是厚度值的正负问题,即负厚度的识别和负号的应用。笔者等曾规定,导线从岩层下层面往上层面方向前进时所控制的岩层厚度为正厚度,导线从岩层上层面往下层面方向前进时所控制的厚度为负厚度,并在沈忠悦公式的基础上,根据岩层面法线与导线之情况相符,选择的参数可直接取自野外实测数据,避免了过程性人工换算环节。

Review of Formula for Calculating The True Thickness of Strata

The calculation of true thickness of strata became much more simple and convenient from the three traditional formulas to the commonly used formula advanced by Shen Zhongyue.Because of the formula of Shen only gives the absolute value of thickness,if often gets wrong total thickness of strata when measuring a stratigraphical section continuously.Wen Pu and Xu Kaili discussed negative thickness separately,but they also gave two selective formulas or signs (positive and negative),and sometimes the selective stipulation is inconsistent with the true case.So the crux of the true thickness calculation of strata is that the value is positive or negative,that is the distinguishing of negative thickness and the applying of negative sign.The author stipulates that thickness of strata consists of the negative thickness measured from upper bedded plane to lower one and the positive thickness measurde from lower bedded plane to upper one.Based on the Calculating formula of Shen Zhongyue and the study of angle between the normal of a bedded plane and the traverse,a accurate and convenient formula of calculating the true thickness of strata was proved.The total thickness of strata summed by this formula tally with the actual situation.Its parameter data can be obtained directly from the field measured records,and needn't make processing conversion.