朱磊 張明義 白曉宇 王永洪 趙天楊
摘要:
通過現場拉拔破壞性試驗,測得不同直徑的GFRP抗浮錨桿在基礎底板內的極限承載力和滑移量,并與實際工程中不同形式的鋼筋抗浮錨桿作比較,分析其承載性能和粘結特性。研究表明,在相同的混凝土強度與養護條件下,相同直徑的GFRP抗浮錨桿的極限承載力、平均粘結強度與鋼筋抗浮錨桿相比較高,且GFRP抗浮錨桿的變形能夠滿足實際工程需求,充分驗證了GFRP材料用作抗浮錨桿的先進性與合理性。基于試驗結果與理論分析,給出了GFRP抗浮錨桿與基礎底板的最佳錨固面積,并提出了計算公式。
關鍵詞:
GFRP抗浮錨桿;承載力;錨固性能;最佳錨固面積;平均粘結強度
中圖分類號:TU470
文獻標志碼:A文章編號:16744764(2017)02010708
Abstract:
Through spot pullout destructive test, ultimate bearing capacity and slippage in the foundation slab of GFRP antifloating anchors with different diameter were monitored. Compared with some kinds of steel antifloating anchors in the actual engineering, their bearing performance and bond behavior were analyzed. The results showed that under the same strength and curing condition of the concrete, ultimate bearing capacity of GFRP antifloating anchor was larger than steel antifloating anchor with same diameter, the average bond strength between GFRP antifloating anchor and foundation slab was higher than the steel antifloating anchor, moreover the deformation of GFRP antifloating anchor can meet the engineering requirements, all of those fully verify that GFRP material as an antifloating anchor was advanced and reasonable. Based on the experimental results and theoretical analysis, the best anchoring area between GFRP anchor and foundation slab was determined, the computational formula was proposed.
Keywords:
GFRP antifloating anchor; bearing capacity; anchorage performance;the best anchoring area;the average bond strength
錨桿結構以其優越的經濟性和較高的可靠性,被廣泛應用于地下抗浮工程,特別是大型地下工程。建筑抗浮工程常位于地下水位以下,錨桿結構因受到地下水中酸、堿離子等的腐蝕作用,而不斷銹蝕、老化,致使其耐久性降低,進而影響建筑物的安全性[12]。玻璃纖維增強聚合物(GFRP)錨桿是近年來發展運用的新型材料錨桿,它具有抗拉強度高、抗腐蝕性能好、抗電磁干擾能力強及松弛性低等優點[3]。由GFRP錨桿在腐蝕環境[4]、砂漿[56]和混凝土[79]中的諸多試驗研究結果可知,將其應用于抗浮工程中不僅可以從根本上解決建(構)筑物抗浮錨桿的耐久性問題,而且解決了地鐵等城市軌道交通建設項目中因雜散電流存在而不能使用抗浮錨桿的問題。……