钻孔灌注桩后压浆法在渭南某工地应用

近年来我国的高层建筑迅猛发展，对地基承载力的要求越来越高，高层建筑的基础形式一般采用灌注桩基础。为了满足设计要求；灌注桩的持力层要求是较为完整的岩石层或承载力较高的卵石层，桩长和桩径尺寸往往很大，使得地下部分的造价在整个工程总造价中占较大的比例；同时；由于桩长很长，也给施工造成很大的困难。渭南市某工地采用φ300mm桩径，桩长30m，试桩施工完成后，经过桩基检测，桩的承载力不能满足上部荷载的要求，其后采用后压浆法来提高桩的侧摩阻力和桩端承载力，从而使灌注桩达到提高基桩承载力、减少基桩沉降的结果。

POST PRESSURE GROUTING PILE OF BOREHOLE USED IN A CONSTRUCTION SITE IN WEINAN

With the development of construction of high buildings in resent years,higher standards for foundation bearing capacity are required.Bored piles for foundation of high buildings are common in China.In order to meet the requirements of construction design,bearing stratum of bored piles is required to be comparatively intact rocks or cobble layers with high bearing capacity.Piles with great length and big size increase the cost ratio of whole subgrade construction and difficulties in construction.At a construction site in Weinan city,bored piles with a diameter of 600 mm and a length of 30m were used in subgrade construction,which couldn’t reach the requirements of load-bearing capacity above.Post pressure grouting of borehole is adopted for increasing side friction of piles and bearing capacity at pile ends,which could enhance the load-bearing capacity of subgrade piles and reduced the possibility of subsidence of subgrade piles.