Lateral soil pressures under at-rest conditions are commonly estimated as K₀ times vertical normal pressure, where K₀ is obtained from generally accepted empirical formulae, related to the soil's friction angle and the stress history. Results of a programme of laterally, rigidly confined, vertical compression and unloading tests on sand and clay are presented, in which two significant experimental techniques were employed: (a) lateral pressures were measured using null pressure gauges, preventing gauge diaphragm deflection; (b) side-wall friction was measured, and minimised using special friction reduction measures. Comparative tests in which one or both of these measures were not employed indicate the significant errors induced in both the vertical and the horizontal pressures used for K₀ determination. The bank of experimental data, which formed the basis for the commonly accepted empirical formulae, did not take account of these issues, and they are shown to be inconsistent with values measured in the present study.

中文翻译：

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使用改进的实验技术确定K0

通常将静止状态下的土壤侧向压力估算为垂直法向压力的K ₀倍，其中K ₀是从公认的经验公式中得出的，该公式与土壤的摩擦角和应力历程有关。的横向的程序的结果，刚性地密闭，在沙子和粘土垂直压缩和卸载测试被呈现，其中两个显著实验技术采用：（一个使用空压力表测定的）横向压力，以防止量规隔膜偏转; （b）测量了侧壁摩擦力，并使用特殊的减少摩擦的措施将其最小化。没有采用这些措施中的一项或两项的比较试验表明，在确定K ₀的垂直压力和水平压力中都引起了明显的误差。大量的实验数据（没有成为这些公认的经验公式的基础）没有考虑这些问题，并且显示出它们与本研究中测得的值不一致。