1-2跨膺架静载预压施工方案
一、预压目的：
在单桩静载试验结果的基础上，检测贝雷梁、横向工字钢、桩体、地基的整体力学性能（局部强度、整体稳定性）；检测各受力单元的沉降变形，为预拱度的设置、膺架搭设质量控制标准提供数据；检测分析桩体在可能的水平力作用下的变位。
二、 预压区选择、预压荷载：
肋与肋之间最小距离为6.15米，通过0.25厘米连接，在砼浇筑后未形成强度前。某肋的自重传递至另一肋为零。选择受力最不利的区域如下图位置进行预压。
预压采用自制顶铁，堆载方式尽可能与施工受力模式吻合，具体见图，预压荷载为砼自重的1.2倍。
 每米预压荷载： （4.836+0.975/2+0.7/2）×2.6×1.2＝17.7t/m，
中横梁处增加荷载：（5.0+6.67/2）×2.4×0.3×2.6×1.2＝13t/处
总加载量：        17.7×16.5+13×3＝331t
三、预压监控点设置：
贝雷梁底、横向工字钢顶及桩顶设高程监测点，钢管桩顶设位移观测点，详细位置如图。
四、 观测方法及数据处理：
高程采用DS3水准仪，位移采用全站仪坐标法
1-2 Cross Scaffolding Construction of static preloading scheme
First, pre-press purposes:
In the static test pile based on the results, detection Bailey beam, transverse beams, piles, foundation, mechanical performance of the (local strength, overall stability); to detect the Settlement by force unit, the pre-arch degree setting, scaffolding erection quality control standards to provide data; testing of piles in the level of force may be under the deflection.
Second, pre-press area selection, pre-press load:
Minimum distance between the rib and rib 6.15 m by 0.25 cm to connect, not after the formation of strength in the Pouring before. Weight transfer of a rib to another rib zero. Select the region by force as shown most unfavorable position preload.
Top with homemade iron preloading, loading mode as far as possible consistent with the construction of the force model, the specific figure, pre-compression load to 1.2 times the weight of concrete.
 Preloading load per meter: (4.836 +0.975 / 2 +0.7 / 2) × 2.6 × 1.2 = 17.7t / m,
Add the load in the beam: (5.0 +6.67 / 2) × 2.4 × 0.3 × 2.6 × 1.2 = 13t / Office
Total load capacity: 17.7 × 16.5 +13 × 3 = 331t
Third, pre-pressure monitoring point settings:
Bailey beam bottom, horizontal I-beam roof and the pile top elevation monitoring points established, steel pipe pile top displacement observation points set up in detail the position of Fig.
Fourth, the observation method and data processing:
DS3 Level Elevation by the displacement method using Total Station coordinates