宋修广+于一凡+张宏博+葛智

摘要：为研究透水性混凝土桩施工中产生的超孔隙水压力的变化规律，通过在现场埋设孔隙水压力计的方法，监测并分析了振动沉管法单桩施工过程中及施工后桩周土体的超孔隙水压力随时间、径向距离及深度的变化，并根据监测结果分析了透水性混凝土桩单桩施工对桩周地基的影响。结果表明：对于高地下水位的粉性土地基，桩周土体的超孔隙水压力在沉管结束时达到最大值，之后消散速率较快，完全消散时间较短，且距桩越近，超孔隙水压力的上升与消散速率越快；超孔隙水压力在径向上与深度上大致呈现递减趋势，距桩越近，超孔隙水压力越大；地基土体的液化范围与加固范围的空间分布呈上大下小的漏斗形。提出的适用于透水性混凝土桩的施工工艺可为类似工程的设计与施工提供参考。

关键词：基础工程；超孔隙水压力；现场试验；透水性混凝土桩；振动沉管；粉土

中图分类号：U411文献标志码：A

Experiment on Variation Characteristics of Excess Pore Water Pressure

During Pervious Concrete Pile ConstructionSONG Xiuguang1，2， YU Yifan1，2， ZHANG Hongbo1，2， GE Zhi1，2

（1. School of Civil Engineering， Shandong University， Jinan 250061， Shandong， China；

2. Shandong Engineering & Technology Research Center for Subgrade Safety， Shandong

University， Jinan 250061， Shandong， China）Abstract： In order to reveal change regulation of excess pore water pressure during pervious concrete pile construction， excess pore water pressure of soil around the pile changing with time， radial distance and depth were monitored and analyzed during and after single pervious concrete pile construction by vibrating sinking pipe through the method of burying pore water pressure gauges in the field， and the effect of single pervious concrete pile construction on foundation around the pile was analyzed according to the monitoring results. The results show that excess pore water pressure of soil around the pile reaches maximum after sinking pipe and afterwards dissipates quickly for silt foundation with high groundwater level. The time of excess pore water pressure disappearing completely is very short. The rates of rise and decrease of excess pore water pressure are faster where it is closer to the pile. The excess pore pressure decreases approximately in radial direction and depth. The excess pore water pressure at same depth of each moment is larger where it is closer to the pile. The spatial distributions of liquefaction scope and reinforcement scope are about a funnel shape. The proposed construction technology suitable for pervious concrete pile can provide reference for design and construction of similar engineering.

Key words： foundation engineering； excess pore water pressure； field test； pervious concrete pile； vibrating sinking pipe； silt

0引言

透水性混凝土是由特定级配的集料、水泥、外加剂、增强剂和水等按特定比例和工艺制成的多孔混凝土，与普通混凝土不同，透水性混凝土主要组成材料仅有少量的细骨料或者不含细骨料。由于该新型混凝土集强度与透水性于一体，在工业与民用建筑、路面工程及园林工程中得到推广应用，并取得了较好的效果。用透水性混凝土浇筑而成的透水性混凝土桩作为软基处理的措……