近海超长大直径钻孔灌注桩事故处理与检测

某桥梁工程的试验桩为混凝土灌注桩,桩长118 m、桩径2 200 mm,由于地质方面原因的影响,超声波检测结果显示在桩身-45.5~-46.8 m范围存在严重缺陷,钻孔取芯结果显示在该范围内有夹泥。本文介绍了该桩的事故处理措施:钻孔、清除夹泥、高压水下切割、清渣和压浆,以及锚桩法静载荷试验检测该桩的极限承载力为38 000 k N,承载力及试桩工程达到预期效果,超长钻孔灌注桩深层土体的摩阻力的实测值要比勘察值小20%~40%,为该桥梁工程桩基工程设计和施工提供了具有参考意义的参数;检测结果验证了上述桩身缺陷处理措施的有效性,为处理混凝土灌注桩类似缺陷积累了经验,并为锚桩法大吨位静载荷试验积累了宝贵的经验。

Accident Treatment and Testing of Overlong Major Diameter Bored Pile Offshore

A test pile for a bridge engineering is concrete bored pile,the pile length is 118 m,and the pile diameter is 2 200 mm.Because of the influence of the geological reasons,the ultrasonic testing results showed that there was a serious defect in the range of-46.8～-45.5 m of the pile body,at the same time,the results of drilling core showed that there were some mud in the same range.Accident treatment measures of the test pile were introduced in detail,these measures included drilling,removal of nud,high pressure water cutting,slag and mud.The ultimate bearing capacity of the test pile was 38 000 kN for static load test of anchor pile reaction force method,the bearing capacity and the test pile project achieved expected results,that side friction resistance measured value of deep soil layer of the test pile was lower 20％ ～ 40％ than the suggested value in survey report.The test results verified the validity of the pile foundation engineering design and construction,and the test results showed that the accident treatment measures were effective,the accident treatment experience of the pile body was accumulated,and the static load test with the method of anchor pile reaction force valuable experience was accumulated.