Construction of retaining wall in general area of new railway project
Content introduction: Newly built mountain railway, river bank slope landform, steep natural cross slope, developed planting slope, overlying Quaternary eluvial deluvial and colluvial sand clay and block stone soil, underlying Shaximiao Formation sandstone, mudstone interbedding, rock mass joints developed, poor integrity, designed as gravity cutting retaining wall and counterweight shoulder retaining wall, The limit retaining wall with a height of more than 12 meters is designed with C15 rubble concrete, and the retaining wall with a height of less than 12 meters is designed with 75~100 # mortar rubble retaining wall. 1. Construction method 1.1 Open excavation of foundation pit: before excavation, an intercepting ditch shall be set at the top (in rainy season). The excavation line shall be determined according to the geological conditions. The excavation shall be carried out in strict accordance with the excavation line. When the wall back is placed in the rock, the setting out can be carried out directly according to the slope of the wall back of the retaining wall section. At the same time, when the upper and lower retaining sections are constructed, the shoulder wall shall be constructed first. The upper retaining wall needs to be excavated in sections. The soil foundation is mainly excavated by machinery (excavation), and paved and shaped by manual trimming: the stone pit is blasted by small cannon, cleaned and transported manually. 10~15cm away from the base, it shall be accurately chiseled to the elevation manually, and the inclined base shall not be built into an inclined plane by filling. In case of rainy days in the excavated and formed foundation pit, a drainage ditch shall be set in the pit, and a water collecting well shall be used to drain the accumulated water to ensure that the base is not soaked. The burial depth of the foundation pit and the geological conditions of the foundation base shall be rechecked when forming the foundation pit. If they are inconsistent, measures shall be taken for construction. 1.2 Masonry wall: the masonry of wall shall be carried out in sections and layers by mortar squeezing method.