Abstract Standard penetration test is often used as an index for prediction of geomaterial elastic and strength properties. It consists of releasing a 63.5 kg hammer from a specified distance of 762 mm on a series of connected drill rods. The N-value is defined after a total 457 mm of penetration is achieved by counting the below counts for the last 300 mm of penetration. This required penetration is not often achieved in weak rocks due to their relatively large compressive strength. To eliminate the need for achieving a total required 457 mm of penetration, a novel approach is introduced where the rate of penetration of the split spoon sampler is used for the characterization of the engineering properties of the weak argillaceous rocks. The rate of penetration is defined as the slope of the final segment of the blow count versus penetration plot. The test results show that the average penetration rate at each test depth approaches a relatively constant value as the penetration increases. It is found that penetration rate is affected by the unconfined compressive strength, deformation modulus, and water content of the rock mass as well as the mean effective stress at the elevation of each test. Using in situ tests from 21 weak rock sites in Illinois, United States, models are proposed for the prediction of deformation modulus and unconfined compressive strength based on the penetration rate. The models account for the influence of mean effective stresses and the in situ water content of rock.

中文翻译：

---

基于标准贯入试验的软弱泥质岩无侧限抗压强度和变形模量预测

摘要 标准贯入试验常被用作预测岩土材料弹性和强度特性的指标。它包括在一系列连接的钻杆上从 762 毫米的指定距离释放 63.5 公斤的锤子。N 值是在通过计算最后 300 毫米穿透的以下计数达到总穿透 457 毫米后定义的。由于其相对较大的抗压强度，在脆弱的岩石中通常无法实现这种所需的穿透力。为了消除达到所需的总穿透 457 毫米的需要，引入了一种新方法，其中裂匙采样器的穿透速率用于表征弱泥质岩的工程特性。穿透率定义为打击次数与穿透图的最后一段的斜率。测试结果表明，随着渗透率的增加，每个测试深度的平均渗透率接近一个相对恒定的值。研究发现，渗透率受无侧限抗压强度、变形模量、岩体含水率以及每次试验标高平均有效应力的影响。使用来自美国伊利诺伊州 21 个弱岩场地的原位试验，提出了基于穿透率预测变形模量和无侧限抗压强度的模型。这些模型考虑了平均有效应力和岩石原位含水量的影响。研究发现，渗透率受无侧限抗压强度、变形模量、岩体含水率以及每次试验标高平均有效应力的影响。使用来自美国伊利诺伊州 21 个弱岩场地的原位试验，提出了基于穿透率预测变形模量和无侧限抗压强度的模型。这些模型考虑了平均有效应力和岩石原位含水量的影响。研究发现，渗透率受无侧限抗压强度、变形模量、岩体含水率以及每次试验标高平均有效应力的影响。使用来自美国伊利诺伊州 21 个弱岩场地的原位试验，提出了基于穿透率预测变形模量和无侧限抗压强度的模型。这些模型考虑了平均有效应力和岩石原位含水量的影响。提出了基于穿透率预测变形模量和无侧限抗压强度的模型。这些模型考虑了平均有效应力和岩石原位含水量的影响。提出了基于穿透率预测变形模量和无侧限抗压强度的模型。这些模型考虑了平均有效应力和岩石原位含水量的影响。