ttTldrotechnical Con.struction. Vol. 3~. No. ~, 2000
ENGINEERING SURVEYS AND THE SAFETY WATER-DEVELOPMENT "WORKS
P R O B L E M OF
I. A . P a r a b u c h e v , V. V. Kayakin and A. V . M u l i n a
Continuing research of stress unloading in open trenches, and also in large underground excavations has demonstrated tile need to account for the development of natural and techno-natural processes over time. Unique data on the change in the velocities of elastic waves and the stress state of a mass at depths of the order of t00-:300 m in tile foundation bed of the high-head dam for the Inguri hydroelectric plant, which were obtained under the guidance of Doctor of Physical and Mathematical Sciences, Academician of the Russian Academy of Natural Sciences A. I. Savich. have been particularly impressive [7]. The problem of assessing the risk of developnmnt of natural and techno-natural processes has received serious attention. According to the data bank on failures, damages, and emergency situations at hydroelectric plants throughout the world [1], 76% of all emergency situations are associated with the development of natural and techno-natural processes (Table 1). Investigation of laws governing natural and techno-natural processes from positions of synergetics [2, 6, 9, 10] has indicated that their development as a function of the existence or absence of equilibrium conditions in tile local system occurs in three characteristic regimes: by a linear stable regime under equilibriuln conditions, in a nonlinear nonstable regime with the disturbance of equilibrium conditions, and in an extrenlal aw~lanche-like regime with accentuation of nonequlibrium conditions. Risk develops when equilibrium conditions are destabilized, and attains a mazdmum under extremal avalanche-like conditions of process development, which is interpreted under everyday conditions as an extreme situation (ES). This approach makes it possible to establish safety criteria for natmal and techno-natural processes on the basis of observational data, and for the most part, enables us to control the development of natural and techno-natm'al processes to prevent extreme situations in a timely fashion and reduce losses [2, 3, 9]. A new form of tasks associated with control of the development of natural and techno-natural processes to maintain water-development works in a stable and safe state is there~bre formulated for engineering surveys [2, 4, 10]. It is completely obvious that solution of the last engineering problems discussed is possible only when tile conditions of all previously enumerated problenis have been fulfilIed. Here, monitoring becomes one of the most important means of engineering surveys [3, 5, 8, 9, 10]. T h e main objective of engineering surveys should be to ensure the safety and reliability of the construction and operation of water-power projects. A tree of the objectives and tasks of engineering surveys for the support of hydraulic construction is shown in Fig. 1. Recognition by surveyors of the need to solve an entire set of problems places engineering surveys on a new qualitative level. In recent years, requirenients to ensure the reliability and safety of water-development works have been seriously tightened. Standards for construction under seismic conditions have been appreciably elevated; design high-water levels have been raised abruptly: and, finally, a federal law concerning the safety of water-development works, which requires the compilation of a declaration on the safety of structures, has been enacted. T h e Russian joint-stock company Unified Power System of Russia has worked steadfastly with surveyors to improve the reliability and safety of water-development works. Under the guidance of Academician of the Russian Academy of Natural Sciences A. I. Savich, an extensive program has been developed and implemented R)r inspection of tile condition of hydroprojects in regions of elevated seismicity. The ServiceCenter for Geodynamic Observations in tile Electric-Power Industry (SCGOEPI) has conducted careflll field inspections of the condition of the foundation beds, abutments, and the structures themselves; data derived from long-term regime observations are being investigated, and so forth. As a result of codification of all available data. models of tile structures, which also inchMe models of the foundation beds and abutments, are being constrncted to assess the earthquake resistance of the structures with consideration given to the change in the condition of the structures and enclosing medimn, and also an inerease in the seismicity of tile region. We should be warned of the creation of an unhealthy agiotage surrounding the reliability and sMety assess-
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 4, pp. 47-49, April, 2000. 0018-8220/00/3404-0193525.00 ©2000 Kluwer Academic/Plenum Publishers
193
T A B L E 1. Effect of Natural. Teehno-Natural. Develoi)ment of D a m Faitures aml E m e r g e n t ~ , Tikhonov. I993) Process Natural processes Including: floods earthquakes karst soil creep ~:;d landslides Techno-natural processes Including: filtration suffosion and washouts erosive washouts settlement slump-type settlement shear detbrmations cryogenic processes Technogenic processe;s Including: caused by design defects caused by construction and equipment defects Total
Concrete dams number % 35 30
' Technogenic Processes on ";. N. Lobrynin and T. O.
Earth dams number 7~, 5:3 30
All types of dams number % 88 30
i1 15 -6 52
12 [3 -5 44
35 11 1 6 86
t9 (J 1 3 18
19 26 1 12 138
16.5 9 0.5 4 46
12 8 6 9 -6 1t 31
10 7 5 8 -5 9 26
29 14 5 17 .4 16 1 :39
16 8 3 10
4l
14
17 M
14 12
1I8
100
"2'2
7
"2"2
1t 26 -t 22 12 70
-1 9 1 7 4 24
1T 22
l0 12
34 36
12 12
178
t00
296
100
'2
9 l
N o t e . The t a b l e is compi' : fronl d a t a - b a n k information on failures, damages, a n d emergency situation:, h e world's h y d r o e l e c t r i c power plants, All-Russian Scientific-Research Institute of H y d r a u l i c Engineering, Saint Petersburg, 1993 [1]. Insignificant changes have been m a d e in the names of tile processes.
ments of w a t e r - d e v e l o p m e n t works. A t tile (:lose of 1999, mass-infornlation media discussed the c o n d i t i o n of the d a m behind the K r a s n o d a r Reservoir as catastrophic. This assessment of the s i t u a t i o n was m a d e b y s e v e r a l scientific coworkers of e d u c a t i o n a l institutions, who did not have sufficient experience in the h y d r a u l i c - c o n s t r u c t i o n practice. T h e stability o f t h e d a m at the K r a s n o d a r Reservoir was a n a l y z e d by the joint-stock c o m p a n y I n s t i t u t G i d r o p r o e k t with the p a r t i c i p a t i o n of tile S C G O E P I : their analysis i n d i c a t e d tile d a n f s high reliability. M i n o r r e p a i r work is required on tile d a m . A sinfilar case also occurred for tile L y u d i n o v o hydroprojeet in the K a l u g a Oblast~ where tile s a m e r e p r e s e n t a t i v e s of certain e d u c a t i o n a l organizations drew tile conchtsion concerning the c a t a s t r o p h i c s t a t e of t h e dam. T h e i-qnt-stock c o m p a n y I n s t i t u t G i d r o p r o e k t p e r f o r m e d surveys to assess tile c o n d i t i o n of t h e d a m , its f o u n d a t i o n bed, a n d abutnlents. A network of I)iezometric holes was created in tile most critical s e c t i o n s , Surveys, observations, a n d analyses of the s t a b i l i t y of tile e a r t h d a m for the Lyudinovo h y d r o p r o j e c t i n d i c a t e d the e n t i t y ' s sufficient reliability. A t tile s a m e time, it was recommended to c o n d u c t certain r e p a i r work, and, for t h e most p a r t . p e r m a n e n t o b s e r v a t i o n s of tile f i l t r a t i o n flows and water levels in tile piezometers. As a result of t h e a n a l y s e s , safety criteria were e s t a b l i s h e d for f i l t r a t i o n flows and piezometric levels, which when exceeded, some o t h e r m e a s u r e s n l a y be required. T h e e x a m p l e s that we have cited suggest tile u n c o n d i t i o n a l need fi)r special surveys a n d r e s e a r c h to assess tile stability of d o m e s t i c h y d r o p r o j e e t s that have seen e x t e n d e d service, and on tile o t h e r hand. t h e u n d e s i r a b i l i t y of negative public assessments of o p e r a t i n g hydroi)rojeets w i t h o u t a p p r o p r i a t e grounds. T h e e x p e r i e n c e a n d t r a d i t i o n s of domestic h y d r a u l i c construction a n d engineering surveys for its s u b s t a n t i a t i o n deserve the g r e a t e s t respect. Conclusions
It has b e c o m e obvious in recent years t h a t the p r i m a r y puri)ose of engineering s u r v e y s is to ensure tile reliability a n d safety of water-power projects. 76% of e m e r g e n c y situations at the world's h y d r o e l e c t r i c p l a n t s ~u'e associated With tile develotmlent of n a t u r a l and t e c h n o - n a t u r a l processes. This superposes a d d i t i o n a l r e q u i r e n l e n t s O I l surveys. L o c a l i z a t i o n of the d e v e l o p m e n t of dangerous processes in space, and the designation of s a f e t y criteria for these processes a r e some of t h e tasks required by engineering surveys. This makes it possible t o s o l v e the m o s t
194
Ensure safety and reliability of construction and performance of water-power projects
/ Investigate state and properties of surrounding medium in region of interaction with water-power project
Ascertain and investigate dangerous natural and techno-natural processes in region of interaction with water-power project
Predict interaction between techno-natural project and surrounding medium and designate safety criteria
\
/
Control development of techno-natural processes to • p r e v e n t E S and maintain entity in stable state
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Fig. 1. Tree of objectives and tasks of engineering surveys to support water-I)ower construction. important problem involving control of natural and techno-natural processes to maintain the entity in a stable safe condition and prevent development of extreme situations in a timely fashion. Surveys and investigations to ensure the safety of water-development works should be performed systematicalb~ but without unhealthy agiotage surrounding unsubstantiated data.
REFERENCES 1.
2.
3.
4.
5. 6.
S. N. Dobrvnin and T. S. Tikhonova, Data Bank of Faib~'res, Damages. a~td EmeTyency Situations at the ~b'r'ld ~ H:qdroelectr~ic Power- Plants. Vesrusskii Nauctmo-Issledovatet'skii Institut Gidrotekhniki imeni t3. Z. Vedeneeva, Saint Petersburg (I993). V. V. Kayakim "Prediction of extreme situations associated with techno-natural processes, and provision for project safety," in: Geoecology [in Russian l, No. 2, Naule~, Moscow (1999). V. V. Kayakin, A. V. Mulina, A. S. Kopytin, and A. V. Andrianov, "Geologic-engineering monitoring to prevent extreme, situations during the opening of a tuImel in a zone of geodynamic activity," in: Procc(~ding,~ of the Ele'~'~:nth Russian Conference on Rock llfech.ar~,ics [in Russian]. Saint Petersburg (1997). V. I. Osipov, "Natural catastrophes and stable development," in: Geoecolog?]. Engi'necri'ng Gcolog?/. HTjdrogeology. Geocr!]ology [in Russian], No. 2, Nauh~, Moscow (1997). I. A. Parabuchev, " P r o b l e m s of engineering surveys and active design of water-development works," Tr. Gidmproekta, No. 113 (1986)_ I. Prigogine and I. Stengers, Order from Chaos [in Russian], Progress, Moscow (1986).
195
?.
8.
9.
10.
196
A. I. Savich, V. G. Adashidze, et al., "Fundamental results of investigation of deformation processes in tile region of the Inguri hydroelectric power plant by geophysical methods," in: Geologic-G(~oph~]sical [n,vestigatio~,s in the Region of th.e Ingur~i H:qdroclectr-ic Power Plant [in Russian], Metsniereba. Tbilisi (1981). A. I. Savich, V. V. Kayakin, and I. A. Parabuchev, "Monitoring of natural-technical systems as applies to large water-development works," in: Concept of Monitoring of the Lithospher'e a'nd Natwral- Tech'nical Entities [in Russian], Institut Fiziki Zemli, Russkaya Ala~demiya Nauk, Moscow (1993). I. V. Semenov. I. L. Dmitrieva, V. V. Kayakin, and A. V. Mulina, "Monitoring in a support system for the ecological safety of water-power projects," Gidrotekh. Stroit., No. 6 (1998). V. V. Kayakin att(t I. A. Paraboutsev, "Prediction and prevention of emergency situations associated with geological processes." in: Eighth Interw,ational irAEG Congress, Vol. 2, Canada. (1998).
