水利水电科技进展
水利水電科技進展
수이수전과기진전
ADVANCES IN SCIENCE AND TECHNOLOGY OF WATER RESOURCES
2015年
1期
89-94
,共6页
钢筋混凝土岔管%围岩稳定%衬砌结构%结构优化%有限单元法
鋼觔混凝土岔管%圍巖穩定%襯砌結構%結構優化%有限單元法
강근혼응토차관%위암은정%츤체결구%결구우화%유한단원법
reinforced concrete bifurcation%surrounding rock stability%lining structure%structure optimization%finite element method ( FEM)
针对钢筋混凝土岔管锐角区围岩稳定性和衬砌结构受力情况复杂的问题，结合某抽水蓄能电站工程实例，建立了引水钢筋混凝土岔管三维数值模型，并对岔管锐角区进行修圆处理。采用有限单元法，对比分析了不同修圆半径下的围岩稳定性及衬砌结构的应力和变形。计算结果表明：与修圆前相比，施工期塑性区范围增加，围岩的塑性区集中程度减缓，但岔管分岔处跨度增大，围岩变形略有增加；运行期岔裆的应力集中程度减缓，钢筋应力集中程度也有所减小，应力分布更加均匀；检修期岔管衬砌主要承受压应力，适当的修圆处理减缓了局部压应力集中程度，对变形影响不大；在外围围岩稳定的基础下尽量减少开挖，选择适当的修圆半径，有利于围岩的稳定和衬砌结构的受力。
針對鋼觔混凝土岔管銳角區圍巖穩定性和襯砌結構受力情況複雜的問題，結閤某抽水蓄能電站工程實例，建立瞭引水鋼觔混凝土岔管三維數值模型，併對岔管銳角區進行脩圓處理。採用有限單元法，對比分析瞭不同脩圓半徑下的圍巖穩定性及襯砌結構的應力和變形。計算結果錶明：與脩圓前相比，施工期塑性區範圍增加，圍巖的塑性區集中程度減緩，但岔管分岔處跨度增大，圍巖變形略有增加；運行期岔襠的應力集中程度減緩，鋼觔應力集中程度也有所減小，應力分佈更加均勻；檢脩期岔管襯砌主要承受壓應力，適噹的脩圓處理減緩瞭跼部壓應力集中程度，對變形影響不大；在外圍圍巖穩定的基礎下儘量減少開挖，選擇適噹的脩圓半徑，有利于圍巖的穩定和襯砌結構的受力。
침대강근혼응토차관예각구위암은정성화츤체결구수력정황복잡적문제，결합모추수축능전참공정실례，건립료인수강근혼응토차관삼유수치모형，병대차관예각구진행수원처리。채용유한단원법，대비분석료불동수원반경하적위암은정성급츤체결구적응력화변형。계산결과표명：여수원전상비，시공기소성구범위증가，위암적소성구집중정도감완，단차관분차처과도증대，위암변형략유증가；운행기차당적응력집중정도감완，강근응력집중정도야유소감소，응력분포경가균균；검수기차관츤체주요승수압응력，괄당적수원처리감완료국부압응력집중정도，대변형영향불대；재외위위암은정적기출하진량감소개알，선택괄당적수원반경，유리우위암적은정화츤체결구적수력。
Surrounding rock stability and lining structure stress in acute angle region of reinforced concrete bifurcation is complex. Based on the practice of a certain pumped-storage power station, three-dimensional numerical model of the diversion bifurcation is proposed and the acute angle of bifurcation is optimized. By using finite element method ( FEM) comparative analysis of stress and deformation of lining structure as well as the surrounding rock stability before and after optimization of different round radius have been performed. Numerical results show that after optimization, the range of plastic zone increases during construction period and the plastic concentration of surrounding rock slows down while the deformation of surrounding rock increases slightly because span at bifurcation point increases. The stress concentration of bifurcation and rebar reduce during operation period, thus the stress distributes more uniform. The bifurcation lining mainly endures compressive stress during overhaul period and the degree of local compressive stress concentration reduces with proper optimization, which has little effect on deformation. Thus, if surrounding rock is stable, one should reduce excavation and choose proper round radius, which is conducive to surrounding rock stability and lining structure stress.
