平衡张力法在拉线门型塔带电更换274号角钢的应用

针对500 kV东长哈输电线路工程的拉线门型塔,在运行过程中存在大部分拉线塔的上部横担中间位置与拉线挂板连接的274号角钢严重变形,严重威胁线路安全的情况,决定对其更换补强。由于此处为连接拉线的主受力点,用常规方法在更换过程中耗时、耗力,提出利用平衡张力法在设备带电的状态下进行常态更换,使送电设备隐患得到了及早排除。

Determination of initial cable force of cantilever casting concrete arch bridge using stress balance and influence matrix methods

Cantilever casting concrete arch bridge using form traveller has a broad application prospect.However,it is difficult to obtain reasonable initial cable force in construction stage.In this study,stress balance and influence matrix methods were developed to determine the initial cable force of cantilever casting concrete arch bridge.The stress balance equation and influence matrix of arch rib critical section were established,and the buckle cable force range was determined by the allowable stress of arch rib critical section.Then a group of buckle cable forces were selected and substituted into the stress balance equation,and the reasonable initial buckle cable force was determined through iteration.Based on the principle of force balance,the initial anchor cable force was determined.In an engineering application example,it is shown that the stress balance and influence matrix methods for the determination of initial cable force are feasible and reliable.The initial cable forces of arch rib segments only need to be adjusted once in the corresponding construction process,which improves the working efficiency and reduces the construction risk.It is found that the methods have great advantages for determining initial cable force in cantilever casting construction process of concrete arch bridge.

Observation on clinical efficacy of tension-balance acupuncture therapy in treating knee osteoarthritis

Objective By comparison of the clinical efficacy of treating knee osteoarthritis with tension-balance acupuncture therapy and conventional acupuncture therapy, the effectiveness of treatment of knee osteoarthritis with tension- balance acupuncture therapy was evaluated. Methods Sixty-three patients with knee osteoarthritis in conformity with the diagnostic criteria were randomly divided into the tension-balance-acupuncture group （32 cases, balance group for short） and the conventional acupuncture group （31 cases, conventional group for short） according to random number table. In the balance group, patients with the pain in the anterior flexor group were needled at Biguan （髀关 ST 31）, Fengshi （风市 GB 31）, Heding （鹤顶 EX-LE 2）,Dubi （犊鼻 ST 35）, Yanglingquan （阳陵泉 GB 34）, Xuehai （血海 SP 10） and Liangqiu （梁丘 ST 34） .Afterwards the patients were repositioned in prone position. They were given the treatment by needling at Huantiao （环跳 GB 30）, Chengfu （承扶 BL 36）, Weizhong （委中 BL 40）, Weiyang （委阳 BL 39）, Yinlingquan （阴陵泉 SP 9）, Ququan （曲泉 LV 8） and Chengshan（承山 BL 57）.Patients with the pain in the posterior extensor group were needled at ST 31, GB 31, EX-LE2, ST 35, GB 34, SP 10 and ST 34 .Then the patients were repositioned in prone position. They were given the treatment by needling at GB 30, BL 36, BL 40, BL 39, SP 9, LV 8 and BL 57. They were treated once a day with five days as a course of treatment and two days as an interval. After three courses, Lequesne indiceses before and after the treatment and clinical efficacy of the treatment were observed. In the conventional group, patients were treated in a sitting position by needling at ST 35, Xiyang （膝眼 EX-LE 5）,Zusanli（足三里 ST 36）, GB 34, Xuanzhong （悬钟 GB 39）, SP 9, EX-LE2, ST 34, Shenshu （肾俞 BL 23） and Pishu （脾俞 20）. They were treated once a day with five days as a course of treatment and two days as an interval. After three courses, the clinical efficacy of the treatment was observed. Results After three courses, improved Lequesne indices score was （5.55± 1.08） in the balance group while improved Lequesne indices score was （2.14 ± 0.57） in the conventional group, indicating that improved Lequesne indices score in the balance group was superior to that of the conventional group with the significant difference （P〈0.05）; efficacy rate in the balance group was 84.37% while that of the conventional group was 58.06%, and efficacy rate in the balance group was superior to that of the conventional group （P〈0.01）. Conclusion Clinical efficacy of treatment of knee osteoarthritis in the balance group was superior to that of the conventional group, worthy of clinical promotion.