后压浆施工+技术规范

后压浆施工技术规范

Technical Specification of Post Pressure Grouting

一、设计design

1、对桩径800mm桩长40m采用复式注浆法即桩端与桩侧注浆法。桩端与桩侧各对称安装二根注浆管。

Double pressure grouting to be adopted for 800mm dia./40m long pile, i.e. side and bottom grouting. Two grouting pipes shall be arranged for bottom and side respectively.

2、注浆位置grouting position：

1）桩端注浆：注浆花管应埋入终孔孔底下100-300mm，

Bottom grouting: grouting pipe should penetrate 100-300mm below the bottom of borehole.

2）桩侧注浆：桩长30m/40m的桩注浆花管应设置在地面下20m/25m处的砂层中，或者15-20m/20-25m处的砂层与粘性土层界面上500mm处，具体位置由各区段工勘探孔及桩钻进时的反渣情况综合判断确定，同一建（构）筑物注浆位置宜相同（详见附图二）。

Side grouting: grouting pipes for 30m/40m piles should be embedded in sand strata 20m/25m underground, or 500mm above the intersection of

15-20m/20-25m silty sand and clay sand. Exact positions shall be reasonably decided as per out-coming soil condition in test boring and actual piling. Grouting position for the same structure (building) is preferably identical. (see diagram 2)

3、注浆管的长度：由实际施工的孔深确定，其长度为实际孔深+0.6m。

Length of grouting pipe: shall be as per actual borehole depth and should be 0.6m longer than borehole depth.

4、注浆管采用DN20、δ=2.75的焊管，相邻注浆管采用丝扣连接，并用14#铁

丝绑扎固定在钢筋笼的外侧。注浆管底端用丝堵封闭，距底端400mm长度范围内对称均匀钻12个φ6的注浆孔，用胶带及图钉封孔。注浆管顶部应高出砼面0.5以上，且高出地面0.2-0.3m。管顶要用丝堵封闭且用不同颜色的胶带缠绕，将桩底注浆管与桩侧注浆管区分开来。

Grouting pipe type: DN20、δ=2.75 welded pipe to be adopted, and adjacent pipes to be connected with threads and tightly fixed to the outer side of rebar cage with 14# galvanized wire. Bottom end of grouting pipe to be sealed with plug and 12 nos ofφ6 grouting holes to be evenly drilled within the bottom 400mm of grouting pipe, and the same should be sealed with tapes and thumbnails. Top of grouting pipe should be 0.5m above concrete level and 0.2-0.5m above ground level. Pipe tops to be sealed with plugs and wrapped with tapes of different colors to differentiate bottom and side grouting pipes.

5、注浆压力：桩侧：桩长30m为1.5 MPa，桩长40m为2.0 MPa ；桩端：桩长30m为2.0 MPa，桩长40m为2.5MPa。

Grouting pressure：pile side: 1.5MPa for 30m piles and 2.0Mpa for 40m piles; pile bottom: 2.0MPa for 30m piles and 2.5 for 40m piles.

6、注浆材料及注浆量：采用普通42.5级水泥，每根桩水泥用量暂定为3.0t。初始压浆时水灰比为1：1，体积为200L，余下水灰比为08:1。

Grouting material and quantity: normal OPC 42.5 grade cement to be adopted and 30t of cement for each pile. Initial grouting water-cement ratio should be 1:1, volume should be 200L and trailing water-cement ratio should be 8:1.

7、成桩2天后开始注水打开通道。28天内进行注浆。

Water to be injected into grouting pipes after 2 days of pile concreting completion so as to clean grouting pipes and pressure grouting to be carried out within 28 days of pile completion