to the use of analyze is more to do with my English skill I will correct that measure is more correct I believe Thank you for pointing out I know a boring machine measures the soil strength as SPT N value From the SPT article a sledgehammer weights 63 5 kg so I believe like in Japan the US counts the number of blows in the interval of 1 m and wash out soil with water and start pounding the hammer again repeating I believe this is what you mean by SPT run in borehole created by a boring machine You said if there is a weak layer in the interval over which the SPT is run it will show up in the test results So i believe what you saying is that if there are several soil layers within an interval of 1 m the result shows the differences even though they only report one SPT N value for each interval Actually I happen to have a SPT N value report on my side right now and the graph shows only one N value for each interval I hope I understand your inteval correctly Correct me if I am wrong At least that is how it is done in Japan I d like to know very much how the difference in the soil strength among different soil layers in the interval shown Educate me Secondly I am very willing to discuss with you I will take back my writing or correct it by myself if i find them wrong So please respect it and do not delete my writings I have never deleted your writings Thirdly you made a PWRI source link as a reference for your writing In the talk page you specifically said you can not read Japanese I have read it and although it is about SPT problems associated with weak layers as a title says the content is quite different from your writing Have you actually read it