To investigate the seismic behavior of specially shaped column joints with X-shaped reinforcement,two groups of specimens with or without X-shaped reinforcement in joint core region were tested under constant axial co...To investigate the seismic behavior of specially shaped column joints with X-shaped reinforcement,two groups of specimens with or without X-shaped reinforcement in joint core region were tested under constant axial compression load and low reversed cyclic loading,which imitated low to moderate earthquake force.The seismic behavior of specially shaped column joints with X-shaped reinforcement in terms of bearing capacity,displacement,ductility,hysteretic curve,stiffness degradation and energy dissipation was studied and compared to that without Xshaped reinforcement in joint core region.With the damage estimation model,the accumulated damage was analyzed.The shearing capacity formula of specially shaped column joints reinforced by X-shaped reinforcement was proposed with a simple form.The test results show that X-shaped reinforcement is an effective measure for improving the seismic behavior of specially shaped column joints including deformation behavior,ductility and hysteretic characteristic.All specimens were damaged with gradual stiffness degeneration.In addition,X-shaped reinforcement in the joint core region is an effective way to lighten the degree of cumulated damage.The good seismic performance obtained from the specially shaped column joint with X-shaped reinforcement can be used in engineering applications.The test value is higher than the calculated value,which indicates that the formula is safe for the design of specially shaped column joints.展开更多
Four exterior joints with special-shaped columns which have different lengths of limbs are tested under low cyclic loading. Speeial-shaped columns adopted are L- and T-shaped in section. It can be concluded that crack...Four exterior joints with special-shaped columns which have different lengths of limbs are tested under low cyclic loading. Speeial-shaped columns adopted are L- and T-shaped in section. It can be concluded that crack pattern, failure mode and shear strength of joints are affected by the length of limb, and that shear strength and ductility increase with the length of limb; the joints with the flexural failure of the beam have better seismic behavior than those with the shear failure of the joint core.展开更多
To meet the requirements of pipeline consumers abroad,in this study,an automatic gas metal arc welding type of girth welding was performed with a heat input of no more than 0.25 kJ/mm and high-strength solid-wire matc...To meet the requirements of pipeline consumers abroad,in this study,an automatic gas metal arc welding type of girth welding was performed with a heat input of no more than 0.25 kJ/mm and high-strength solid-wire matching for an X70M large-diameter UOE pipeline.An integral evaluation of the X70M pipeline girth weldability was performed with respect to the girth-weld cold-cracking sensitivity during the welding process and the strengthening,hardening,and embrittlement of the girth weld joint after girth welding in especially rigorous welding conditions with accelerated failure characteristics.The performance of the above girth weld joint with joints welded using the main construction-field girth welding procedure was compared to ensure the good girth weldability of the X70M pipeline.The results of this study have important supervisory significance for field-construction girth welding.Finally,the girth weldability of the X70M pipeline was found to satisfy the field construction requirements even when the welding conditions are especially rigorous.展开更多
为了研究含裂隙岩体边坡滑移特征和控制方法,以含裂隙岩体边坡为研究对象,采用FLAC3D软件模拟了边坡滑移特征;通过岩体力学试验,研究了不同温度对岩体强度的影响以及特制浆改善岩体力学特征;提出了“锚杆+锚索+锚喷+注浆”联合加固控制...为了研究含裂隙岩体边坡滑移特征和控制方法,以含裂隙岩体边坡为研究对象,采用FLAC3D软件模拟了边坡滑移特征;通过岩体力学试验,研究了不同温度对岩体强度的影响以及特制浆改善岩体力学特征;提出了“锚杆+锚索+锚喷+注浆”联合加固控制技术,结合现场试验,验证控制技术可行性。研究结果表明:边坡岩体由上向下沿滑坡面发生破坏,形成上下应力集中区,为重点控制区;具有减水性、黏结性和抗高温性试剂A的浆体促进加固岩体结构耦合,同时阻碍岩体强度随温度升高而衰减特性,抗衰减性提高2倍;效果试验中,边坡岩体最大位移值为64.9mm,锚固力保持70 k N以上。展开更多
目的观察耳穴疗法用于全膝关节置换术围手术期镇痛的效果。方法选择ASAⅠ～Ⅲ级行单侧全膝关节置换骨性关节炎患者60例,随机分为耳穴镇痛组和对照组,每组30例,所有患者手术均由同一组医师施行,实施气管插管全身麻醉。耳穴镇痛组患者术...目的观察耳穴疗法用于全膝关节置换术围手术期镇痛的效果。方法选择ASAⅠ～Ⅲ级行单侧全膝关节置换骨性关节炎患者60例,随机分为耳穴镇痛组和对照组,每组30例,所有患者手术均由同一组医师施行,实施气管插管全身麻醉。耳穴镇痛组患者术前用王不留行籽按压耳穴配合术后患肢局部穴位敷贴镇痛,对照组采用常规治疗,两组患者均术前1天口服塞来昔布400 mg,术后口服塞来昔布每日2次,每次200 mg。当视觉模拟评分(visual analogue scales,VAS)>7分时,予盐酸布桂嗪0.1 g补救。术后两组采用相同的锻炼方法。记录静息时的VAS评分,镇静满意度,发生不良反应情况,术后膝关节活动度(range of motion,ROM)及美国特种外科医院膝关节评分(hospital for special surgery scores,HSS)。结果耳穴镇痛组患者术后6、24 h的静息VAS疼痛评分分别为(5.99±0.67)、(4.26±0.59)分,均明显低于对照组患者(7.02±0.85,4.92±0.43,P<0.01);两组患者术后1、48 h VAS评分差异无统计学意义(P>0.05);两组患者镇静满意程度总体相似;与对照组比较,耳穴镇痛组患者并发症发生率减少,但差异无统计学意义(4:11,P>0.05);ROM和HSS评分方面,耳穴镇痛组术前ROM为75.63°±5.74°,对照组术前ROM为75.43°±5.63°,差异无统计学意义(P>0.05);耳穴镇痛组术后2周主动与被动ROM分别为96.50°±3.79°、107.8°±3.37°,对照组分别为93.50°±3.50°、105.27°±3.25°,均有统计学意义(P<0.05);耳穴镇痛组术前HSS评分为(60.23±3.44)分,对照组为(61.70±2.83)分,差异无统计学意义(P>0.05);术后HSS评分分别为(86.97±2.33)、(85.37±2.30)分,差异有统计学意义(P<0.05)。结论膝关节置换术围手术期配合应用耳穴疗法有助于减轻患者的术后疼痛,减少术后总的麻醉剂使用量,有助于患者的早期康复,同时有着费用低、并发症少、操作简单、安全的优点。展开更多
基金Supported by National Natural Science Foundation of China (No. 50878141)Hebei Natural Science Foundation,China (No. E2011202013)High School of Hebei Science and Technology Research Youth Foundation,China(No. Q2012083)
文摘To investigate the seismic behavior of specially shaped column joints with X-shaped reinforcement,two groups of specimens with or without X-shaped reinforcement in joint core region were tested under constant axial compression load and low reversed cyclic loading,which imitated low to moderate earthquake force.The seismic behavior of specially shaped column joints with X-shaped reinforcement in terms of bearing capacity,displacement,ductility,hysteretic curve,stiffness degradation and energy dissipation was studied and compared to that without Xshaped reinforcement in joint core region.With the damage estimation model,the accumulated damage was analyzed.The shearing capacity formula of specially shaped column joints reinforced by X-shaped reinforcement was proposed with a simple form.The test results show that X-shaped reinforcement is an effective measure for improving the seismic behavior of specially shaped column joints including deformation behavior,ductility and hysteretic characteristic.All specimens were damaged with gradual stiffness degeneration.In addition,X-shaped reinforcement in the joint core region is an effective way to lighten the degree of cumulated damage.The good seismic performance obtained from the specially shaped column joint with X-shaped reinforcement can be used in engineering applications.The test value is higher than the calculated value,which indicates that the formula is safe for the design of specially shaped column joints.
文摘Four exterior joints with special-shaped columns which have different lengths of limbs are tested under low cyclic loading. Speeial-shaped columns adopted are L- and T-shaped in section. It can be concluded that crack pattern, failure mode and shear strength of joints are affected by the length of limb, and that shear strength and ductility increase with the length of limb; the joints with the flexural failure of the beam have better seismic behavior than those with the shear failure of the joint core.
文摘To meet the requirements of pipeline consumers abroad,in this study,an automatic gas metal arc welding type of girth welding was performed with a heat input of no more than 0.25 kJ/mm and high-strength solid-wire matching for an X70M large-diameter UOE pipeline.An integral evaluation of the X70M pipeline girth weldability was performed with respect to the girth-weld cold-cracking sensitivity during the welding process and the strengthening,hardening,and embrittlement of the girth weld joint after girth welding in especially rigorous welding conditions with accelerated failure characteristics.The performance of the above girth weld joint with joints welded using the main construction-field girth welding procedure was compared to ensure the good girth weldability of the X70M pipeline.The results of this study have important supervisory significance for field-construction girth welding.Finally,the girth weldability of the X70M pipeline was found to satisfy the field construction requirements even when the welding conditions are especially rigorous.
文摘为了研究含裂隙岩体边坡滑移特征和控制方法,以含裂隙岩体边坡为研究对象,采用FLAC3D软件模拟了边坡滑移特征;通过岩体力学试验,研究了不同温度对岩体强度的影响以及特制浆改善岩体力学特征;提出了“锚杆+锚索+锚喷+注浆”联合加固控制技术,结合现场试验,验证控制技术可行性。研究结果表明:边坡岩体由上向下沿滑坡面发生破坏,形成上下应力集中区,为重点控制区;具有减水性、黏结性和抗高温性试剂A的浆体促进加固岩体结构耦合,同时阻碍岩体强度随温度升高而衰减特性,抗衰减性提高2倍;效果试验中,边坡岩体最大位移值为64.9mm,锚固力保持70 k N以上。
文摘目的观察耳穴疗法用于全膝关节置换术围手术期镇痛的效果。方法选择ASAⅠ～Ⅲ级行单侧全膝关节置换骨性关节炎患者60例,随机分为耳穴镇痛组和对照组,每组30例,所有患者手术均由同一组医师施行,实施气管插管全身麻醉。耳穴镇痛组患者术前用王不留行籽按压耳穴配合术后患肢局部穴位敷贴镇痛,对照组采用常规治疗,两组患者均术前1天口服塞来昔布400 mg,术后口服塞来昔布每日2次,每次200 mg。当视觉模拟评分(visual analogue scales,VAS)>7分时,予盐酸布桂嗪0.1 g补救。术后两组采用相同的锻炼方法。记录静息时的VAS评分,镇静满意度,发生不良反应情况,术后膝关节活动度(range of motion,ROM)及美国特种外科医院膝关节评分(hospital for special surgery scores,HSS)。结果耳穴镇痛组患者术后6、24 h的静息VAS疼痛评分分别为(5.99±0.67)、(4.26±0.59)分,均明显低于对照组患者(7.02±0.85,4.92±0.43,P<0.01);两组患者术后1、48 h VAS评分差异无统计学意义(P>0.05);两组患者镇静满意程度总体相似;与对照组比较,耳穴镇痛组患者并发症发生率减少,但差异无统计学意义(4:11,P>0.05);ROM和HSS评分方面,耳穴镇痛组术前ROM为75.63°±5.74°,对照组术前ROM为75.43°±5.63°,差异无统计学意义(P>0.05);耳穴镇痛组术后2周主动与被动ROM分别为96.50°±3.79°、107.8°±3.37°,对照组分别为93.50°±3.50°、105.27°±3.25°,均有统计学意义(P<0.05);耳穴镇痛组术前HSS评分为(60.23±3.44)分,对照组为(61.70±2.83)分,差异无统计学意义(P>0.05);术后HSS评分分别为(86.97±2.33)、(85.37±2.30)分,差异有统计学意义(P<0.05)。结论膝关节置换术围手术期配合应用耳穴疗法有助于减轻患者的术后疼痛,减少术后总的麻醉剂使用量,有助于患者的早期康复,同时有着费用低、并发症少、操作简单、安全的优点。
