天津市市政工程管道工程砂石基础技术交底记录.doc

交底内容：
交底部位：工程起点—W2
1、 沟槽经验收合格后，回填土石硝至差250mm到设计标高，分层夯实。按设计要求，铺设3.0米宽，0.25米厚，直径为2~25mm的级配碎石，再铺设20mm的粗砂，此时，砂石基础标高高于设计标高20mm，备于管道自沉降。
管底必须与砂石平基及管座紧密接触，石子与管皮不得直接接触，施工期间，槽底不准受水浸泡，平基厚度允许偏差为±20mm之间。垫层厚度不得小于设计规定。
Cards on the table contents:
Cards on the table position: Project start-W2
1, trench after their acceptance, poor backfill debris nitrate to 250mm to the design elevation, hierarchical compaction. According to the design, the laying of 3.0 meters wide and 0.25 m thick with a diameter of 2 ~ 25mm graded crushed stone, and then laying 20mm of coarse sand, this time, based on elevation higher than the design elevation gravel 20mm, prepared in the pipeline from the settlement.
Sand pipe end must be in close contact Dan Pingji and seat tube, gravel and pipe shall not direct contact with skin, the construction period, are not allowed to be immersed in water bottom, flat base to allow deviation of ± 20mm thickness between. Cushion thickness of not less than the design requirements.