西堠门大桥锚碇岩基原位试验

In-Situ Tests for Rock Foundation of Anchorage of Xihoumen Bridge

西堠门大桥是舟山大陆连岛工程的第4座桥,为非对称结构形式的悬索桥。该桥南北锚碇均采用重力式锚,锚碇处地质结构复杂。对南锚碇基坑底面岩基进行承载能力原位试验及摩阻系数原位试验。试验结果表明,锚碇基坑岩基承载力满足设计取值要求。在各级设计正应力下,混凝土试件与岩基接触面的剪切破坏不是发生在两者的胶结面,而是试件区域的岩基首先被剪坏,地基岩石全部碎裂,试验确定的摩阻系数允许值为0.61。

Xihoumen Bridge is the fourth bridge of the Zhoushan Mainland and Islands Link Project and is a suspension bridge of asymmetric structure. The south and north anchorages of the Bridge are all of gravity type anchorages and the geologic structures at the sites where the anchorages are located are complicated. The in-situ tests for the bearing capacity and frictional resistance coefficient of the rock foundation at the bottom of the south anchorage foundation pit were made. The results of the tests indicate that the bearing capacity of the rock foundation meets the values selected for the design. At different levels of the designed normal stress, the shear failure at the contact between the tested concrete slab and the rock foundation does not occur between the binding surface of the slab and rock, instead, the rock in the range of the tested slab fails first due to the shear force, the rock completely crashes and the allowable value of the frictional resistance coefficient determined by the tests is 0.61.