东海大桥陆上段基础持力层均匀性分析设计

东海大桥陆上段约长 2 .4km,为 4～ 6跨一联的 PC连续梁桥 ,基础持力层取 71-2 层 ,即灰黄色粉砂层 ,根据地质钻孔资料综合分析 ,认为持力层以上的 71-1,即草黄色砂质粉土较均匀 ;71-2 层的标准贯入度 N63 .5及比贯入阻力 Ps的变异系数 δ较大 ,反映了持力层较大的不均匀性 ,在沉桩施工中则出现相应不规则的断续分布、突发性较大变化。对此 ,设计采取了相应的应对措施 ,并与管理、施工等有关部门密切联系协作 ,及时妥善处理

Analysis of Uniformity of Bearing Stratum of Foundation of Land Sections of Donghai Bridge and Measures of Design and Construction

The land section of Donghai Bridge has about 2.4km long, is a PC continuous beam bridge with 4~6 spans as one unit.(7) 1-2 stratum is taken as the foundation bearing stratum,i.e. greyish yellow silty sand stratum. According to the comprehensive analysis of geological boring data it thinks that (7) 1-1 stratum above the bearing stratum, i.e. grass yellow sand silty soil is more even. The standard penetration N 63.5 of (7) 1-2 stratum and the variation factor δ of specific penetration resistance P S are greater, so it reflects the greater unevenness of the bearing stratum. So the corresponding irregular and intermittent distribution and the greater sudden variation appear in the construction of sunk piles. Therfore, the corresponding responding measure is taken in the design and it closely connects with the relevant departments of management and construction etc. for cooperation and careful and skilful handling in time.