人工挖孔桩承载力特征值+抗拔承载力计算-省规范

1.桩身承载力设计值计算Q<=ApfcΨcRZH1RZH4RZH5RZH6RZH7RZH8RZH9RZH10桩直径12001400160016001800200022002200采用砼等级C25C30C30C30C30C30C30C30对应砼强度设计值11.914.314.314.314.314.314.314.3工作条件系数0.70.70.70.70.70.70.70.7桩身承载力设计值94162321.5E+072E+072E+072.5E+073.1E+073.8E+073.8E+07桩身承载力特征值6974.98711408.414900.814900.818858.823282.528171.828171.8桩直径/2）×（桩直径/2）×3.14×砼强度设计值×工作条件系数桩身承载力特征值＝桩身承载力设计值/1.352.人工挖孔灌注桩承载力计算Ra=qpaAp《地基》规范（8.5.5-2公式)DqpaApRa＝取Ra=180018002.5434280018006.1544300018007.06532001800360018003800180042001800440018008.038410.173611.335413.847415.1976366251800043074.558159.166869.42000023500275004578.1217232.32119525722.945001000012300143003.人工挖孔灌注桩抗拔力计算Dμqsiali入Qsa＝μ*qsia*li*入RZH1120018003.7686040.55497.376RZH7180036005.6526040.55746.064μiqsiali入Qsa＝μ*qsia*li*入Tuk＝Qsa1＋Qsa2Nk(单桩抗拔承载力特征值)=Tuk/2取Nk=4.桩身抗拔计算N≤fyAs+fpyApy,其中N=3310kNNfyAs331030011033.35.6528040.851537.3442034.721017.36100011.3048090.856918.057664.113832.063310KN实际配筋 32Ф22121605.裂缝宽度验算据地探报告可知环境类别为二a，最大裂缝宽度限值可取0.2mmAsAteρte=180032Ф22121602543400As/Ate0.004781deqftkNkσsk=ψ=1.1-0.65*ftk/(ρte*σsk)222.013310000272.2039Nk/As0.096087max=αcr*ψ*σsk*(1.9c+0.08deq/ρte)/Es其中αcr=c=Es=ωmax=计算裂缝宽度ωmax<限值0.2mm，符合要求2.7502000000.163527(满足）