| Steel Lined Reinforced Concrete Penstock(SLRCP) is raised by the experts of Russia, which was firstly applied to hydropower station during 1960s to 1970s. Since SLRCP is placed on the downstream of the dam, it has specific advantages. In China hydropower station, SLRCP is firstly used in Dongjiang. Later, this type of penstock is used in Jinshuitan, Jinjiang, Taolinkou, Wuqiangxi, Lijiaxia, Jinghong, and also in the largest hydropower station: Three-Gorge hydropower station.However, some defects are discovered along with the extensive application of SLRCP. 〤rack occurs during the construction period of SLRCP in Lijiaxian hydropower station, which generate the study of SLRCP construction period ; 〢ccording to the survey of SLRCP which runs for years, the crack width exceed the design width. So, the crack control is focused.Therefore, the first part of this paper is focused on this two aspects. To make the calculation result practical, the SLRCP of Three-Gorge hydropower station acts as the specimen. The following aspects are studied:1. A concrete construction simulating software FZFX3D is accomplished. This software can deal with three-dimension sequence concrete placement, concrete creep stress calculation. ANSYS is applied to the pre-processor and post-processor stage. The interface program for exchanging data between FZFX3D and ANSYS is also written. One new software thought is firstly raised: combining the concrete simulating software with the commercial FEA software, and at the same time, take full advantage of each software. This thought is better than the conventional software thought;2. The SLRCP construction of No. 9 steel-tube dam monolith of Three-Gorges hydropower station left workshop is studied. Threeaspects are studied:畉he temperature field and stress field of penstock during construction period;?the initial temperature and stress status of penstock before subjected to internal water pressure;(3)the optimization of the penstock construction;3. Alive construction simulating is applied to simulate the No. 9 monolith construction process of Three Gorges hydropower station. The results indicate that the values of the monitoring instruments coincide with the calculated results. Compared with traditional construction simulating, alive construction simulating is necessary during the construction of large hydropower station. It can reflect the dams' alive temperature and stress field, so the dam status can be monitored.4. An ANSYS-based FEA model to calculate the thermal loads applying on SLRCP is raised. This model can calculate the exact crack width and steel stress of SLRCP. The calculated results coincide well with the model experiment, which assure the exaction of FEA model.The accurate calculate method can not solve the crack control problem of SLRCP. So, changing the material property of SLRCP to decrease the crack width or to avoid the crack to happen is a good method. This method can keep the advantage of SLRCP, and at the same time avoid its disadvantage.So, two new SLRCP .is presented: Steel lined steel fiber reinforced concrete penstock(SLSFRCP),Steel lined steel fiber self-stress reinforced concrete penstock(SLSFSRCP). Some pioneer research about SLSFRCP and SLSFSRCP is given below.1. The scale of the model is 1 against 10. Three kinds penstock model are made: SLRCP, SLSFRCP, SLSFSRCP. -A new load equipment is invented in the model test;2. The model test results indicate: SLSFRCP has a better ability to control crack; SLSFSRCP has a better ability to avoid crack. These can make up the shortcoming of SLRCP;23. To study the steel stress development of penstock, ring-form SLSFSRCP and horse-shoe SLSFSRCP during curing period are monitored. The pre-tension stress due to expansion of self-stressing concrete can be used in design;4. The long-term property of steel fiber self-stressing concrete is studied. The results indicate that this material has a good long-term stability. The expansive deformation of 5 years is equal to 90...
|
PDF Full Text Request