中文摘要：

动力触探试验是西部地区河床覆盖层原位测试最常用的方法之一,其探测深度最大可达到上百米,在应用动力触探试验成果时,锤击数需要进行杆长修正,而目前岩土工程勘察规范中关于动力触探杆长修正问题,只给出了20 m范围内的杆长修正系数,深度超过20 m后的动力触探试验成果应该如何进行杆长修正,规范并无规定,规范已经不能满足生产需要,这也是限制该方法应用的关键问题。针对重型动力触探杆长修正问题,在室内进行不同杆长的重型动力触探模型试验,地基土材料为砂砾石和中粗砂两种,最大杆长达到83 m。通过模型试验,获得了重型动力触探杆长修正系数,重型动力触探杆长修正系数符合牛顿弹性碰撞理论,且与地基土材料特性和上覆压力无关。最后给出了推荐的重型动力触探杆长修正系数。

英文摘要：

The dynamic penetration test (DPT) is one of widely applied in situ test techniques in bed covering of western region in China. The rod length during operation can be as long as hundreds of meters, and it should be modified in practical applications. On the modification of dynamic penetration rod length, the modified coefficient is proposed only in the range of 20 m in China's standard “Code for investigation of geotechnical engineering”,but how to modify has no provisions when the depth is more than 20 m. So the standard is unable to meet the production needs, and becomes a major issue that limits its applications. Indoor model tests are carried out for the modification issue, and heavy dynamic penetration model are conducted on sand and gravel soil with series of rod lengths (2.0 m, 8.9 m, 16.4 m, 23.4 m, 30.0 m, 36.0 m, 62.0 m, 83.0 m). The modification coefficient of heavy dynamic penetration rod length is obtained after the tests. It is analyzed and concluded that the modification of heavy dynamic penetration rod length obeys the description of Newton elastic collision theory, and is independent of the material properties and overburden pressure. Finally, the modified coefficient of dynamic penetration rod length is proposed.