中国安全生产科学技术
中國安全生產科學技術
중국안전생산과학기술
Journal of Safety Science and Technology
2015年
9期
24-30
,共7页
小净距隧道%强度折减法%刚度退化%围岩稳定性%塑性区
小淨距隧道%彊度摺減法%剛度退化%圍巖穩定性%塑性區
소정거수도%강도절감법%강도퇴화%위암은정성%소성구
neighborhood tunnel%strength reduction method%stiffness degradation%stability of surrounding rock%plastic zone
运用刚度退化的基本原理和方法，将泊松比ν和弹性模量E进行调整，提出变刚度隧道围岩强度折减法。以某小净距隧道为例，在只调整ν或E、同时调整ν和E、保持ν和E不变4种情况下，探讨了刚度退化对小净距隧道围岩稳定性的影响。结果表明：ν对隧道拱顶下沉、拱底沉降、最大主应力的影响要强于E；隧道两拱脚向内位移随折减系数的增大而增大，内侧拱脚向内位移比外侧拱脚的要大，且在刚度调整时拱脚位移要比保持刚度不变时大；等效塑性应变随折减系数的增大而增大，刚度调整导致等效塑性应变区减小，考虑刚度退化推迟了中夹岩柱塑性区贯通；将变刚度隧道围岩强度折减法应用于小净距隧道工程围岩稳定性评价，可依据安全系数的大小来评判设计的合理性，为支护参数及施工技术的选用提供参考。
運用剛度退化的基本原理和方法，將泊鬆比ν和彈性模量E進行調整，提齣變剛度隧道圍巖彊度摺減法。以某小淨距隧道為例，在隻調整ν或E、同時調整ν和E、保持ν和E不變4種情況下，探討瞭剛度退化對小淨距隧道圍巖穩定性的影響。結果錶明：ν對隧道拱頂下沉、拱底沉降、最大主應力的影響要彊于E；隧道兩拱腳嚮內位移隨摺減繫數的增大而增大，內側拱腳嚮內位移比外側拱腳的要大，且在剛度調整時拱腳位移要比保持剛度不變時大；等效塑性應變隨摺減繫數的增大而增大，剛度調整導緻等效塑性應變區減小，攷慮剛度退化推遲瞭中夾巖柱塑性區貫通；將變剛度隧道圍巖彊度摺減法應用于小淨距隧道工程圍巖穩定性評價，可依據安全繫數的大小來評判設計的閤理性，為支護參數及施工技術的選用提供參攷。
운용강도퇴화적기본원리화방법，장박송비ν화탄성모량E진행조정，제출변강도수도위암강도절감법。이모소정거수도위례，재지조정ν혹E、동시조정ν화E、보지ν화E불변4충정황하，탐토료강도퇴화대소정거수도위암은정성적영향。결과표명：ν대수도공정하침、공저침강、최대주응력적영향요강우E；수도량공각향내위이수절감계수적증대이증대，내측공각향내위이비외측공각적요대，차재강도조정시공각위이요비보지강도불변시대；등효소성응변수절감계수적증대이증대，강도조정도치등효소성응변구감소，고필강도퇴화추지료중협암주소성구관통；장변강도수도위암강도절감법응용우소정거수도공정위암은정성평개，가의거안전계수적대소래평판설계적합이성，위지호삼수급시공기술적선용제공삼고。
Based on the basic principle and method of stiffness degradation, the Poisson's ratio ( v) and elastic modulus ( E) were adjusted, and a strength reduction method of surrounding rock in tunnel with variable stiffness was proposed.Taking a certain neighborhood tunnel as example, the influence of stiffness degradation on stability of surrounding rock in neighborhood tunnel was discussed under four conditions, such as only adjusting v or E, ad-justing v and E at the same time, and keeping the v and E constant.The results showed that the v has stronger in-fluence on arch settlement, dome settlement, and the maximum principal stress than E.The higher of the reduction factor, the inwards displacement of tunnel arch springing is greater.The displacement of inside arch springing is bigger than that of outside arch springing, and the displacement under the condition of stiffness adjustment is grea-ter than that keeping stiffness constant.The equivalent plastic strain increases with the growth of reduction factor. The stiffness adjustment leads to the decrease of equivalent plastic strain zone.Considering the stiffness degrada-tion, the transfixion of interval pillar plastic zone is delayed.When the strength reduction method of surrounding rock in tunnel with variable stiffness is used to stability evaluation of surrounding rock in neighborhood tunnel, the rationality of design can be judged according to the size of safety factor, so as to provide references for the selection of support parameters and construction technology.
