某静压桩压桩力与静载试验成果对比分析

Static Load Test Results on Static Pressed-in Square Piles

某项目选用12根静压方桩进行破坏性试桩,为工程桩设计提供依据。通过理论计算各单桩理论极限承载力特征值,再换算成标准值(简称理论值)后,与单桩竖向抗压承载力极限值(简称试验值)进行对比,并通过监测压桩过程中压桩力峰值及终止压力,分析理论值与试验值及终止压力的关系,发现对于黏性土为持力层的桩压桩终止压力较试验值小,砂性土为持力层的桩压桩终止压力较试验值大;以黏性土为持力层的长桩基试验值与理论值符合单变量线性回归方程且拟合程度高。观察压桩力峰值出现时桩端所处地层,得出指导工程桩施工的一些建议。

In a project,12 static pressed-in square piles were selected for the sacrificial static pile loading testing,which provides a basis for the design of production piles.By calculating the characteristic values of the theoretical ultimate axial capacity of each single pile,and then converting them into the standard values(hereinafter referred to as theoretical values)and comparing them with the ultimate axial capacity of the single pile under the vertical compression(hereinafter referred to as test values),the relationship between the theoretical value and the experimental value and the ending pressure are analyzed by monitoring the peak value and the ending pressure.It is found that the end pressure of the pile with clay soil as bearing stratum is smaller than the test value,and the end pressure of the pile with sandy soil as bearing stratum is larger than the test value The experimental and theoretical values of the long pile foundation with clayey soil as bearing stratum accord with the linear regression equation of single variable and the fitting degree is high.Suggestions to guide the construction of the production piles are obtained by observing the stratum where the pile tip is located when the peak of pile pressure presented.