一、引言 因为钻孔桩适合于各类土层和岩层,且易于施工,所需设备简单,特别当采用单排桩时,由于不必设承台,施工更为简便,进度快,造价低,所以近十多年来已成为桥梁基础最普遍采用的形式。 钻孔桩受力特点是当用旋转钻或冲抓钻施钻成孔的桩壁多为凸凹不平,加之壁土因 I. INTRODUCTION Because bored piles are suitable for all kinds of soil layers and rock formations and are easy to construct, the required equipment is simple. Especially when using a single row of piles, the bored pile is not required to be installed. The construction is simple, fast, low in cost, Therefore, over the past ten years has become the most commonly used form of bridge foundation. Bored pile stress characteristics is that when using rotary drilling or punching drill into the hole into the pile wall mostly rugged,