Performance Investigation and Design of Pile-to-Pile Cap Connections Subject to Uplift
Performance Investigation and Design of Pile-to-Pile Cap Connections Subject to Uplift
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DOI：
10.1177/0361198118796733
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发表时间：
2018-09
影响因子：
1.7
通讯作者：
Philip P. Iekel;B. Phares;Michael Nop
中科院分区：
文献类型：
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作者：
Philip P. Iekel;B. Phares;Michael Nop
桥梁下部结构部件的设计可以抵抗重力，如恒载和车辆活载，以及侧向力，包括风、车辆制动和离心力的影响。显著的侧向力可以在基础的某些部分产生“隆起”的条件。对当前设计技术的回顾表明，由于在这一领域进行的研究很少，各州机构在设计过程中缺乏一致性。此外，批准在现场使用的提升锚没有经过测试。为了缩小这一差距，在爱荷华州立大学结构工程实验室制作了21个全尺寸h型钢桩试件进行测试，以测试静拉荷载下桩承台连接的能力。为了了解连接的行为，并确定合适的锚固细节和隆起情况下的设计方法，在有锚固和没有锚固以及12”和24”埋深的情况下进行了浇铸。研究结果显示：(i)裸桩的承载力一般被低估，可在提升设计中更经常考虑；（ii）混凝土开裂导致这些类型连接中的粘结丧失；正向锚固或预埋延伸至基础下部钢筋垫层之上，以形成高容量连接。
Substructure bridge components are designed to resist gravitational forces such as dead load and vehicular live load, as well as lateral forces including wind, vehicular braking, and centrifugal force effects. Significant lateral forces can create “uplift” conditions on some portions of the foundation. A review of current design techniques regarding uplift in the pile-to-pile cap connection indicates a lack of uniformity in the design process across state agencies stemming from minimal research performed in this area. In addition, approved uplift anchors for use in the field have not been tested. In order to close this gap, twenty-one full-scale steel H-pile specimens were fabricated and tested in Iowa State University’s Structural Engineering Laboratory to test the capacity of the pile-to-pile cap connection under static tensile loading. Specimens were cast both with and without anchorage and with 12” and 24” embedment depths in order to understand the behavior of the connection and to determine a suitable anchorage detail and design approach for uplift cases. Findings revealed that: (i) capacity of bare piles is generally underestimated and could be more frequently considered for uplift design; (ii) concrete cracking leads to a loss of bond in these types of connections; and (iii) positive anchorage or embedment that extends above the lower rebar mat of the footing is necessary to develop a high capacity connection.