In this paper, the distributed element model, which is consisting of a elastic-plastic elements with different yield and breaking strain, is applied to the expression of complete stress-strain curve for uniaxial compression of concrete. Brief of the result of this investigation was follows. (1) The following equation can be derived to express the complete stress-strain curve for uniaxial compression of concrete. S=E(x + x_y・αx^β)e^<αx^β>…(1) where, S=relative stress x=relative strain xy=relative yield strain E=Young's Modulus=[numerical formula] a=[numerical formula] Paramete β and relative yield strain xy is defined by experiment. (2) Parameter β is varied by mechanical and geometrical homogeneity, relative yield strain xy is defined by the first kink point of stress -strain curve of concrete. The complete stress-strain curve of concrete is sensitive to para-meter β and insensitive to rerative yield stra in xy. (3) The following equation is applied to the practical expression of complete stress-strain curve of concrete. S=Exe^<-αx^β>…(2) (4) When parameter β=1, equation (1) and (2) is equal to Smith & Young's eouation.

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Elastic columns extending vertically play an important role in mitigating damage concentration in multi-story structures subjected to earthquakes. Such columns are termed by "spreader columns". In the previous paper, the spreader columns were dealt with mainly as conceptual models. In this paper, it is made clear that some plastification of the spreader column does not hinder its damage dispersing property, and a more general and practical application of the spreader column is discussed.

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By the experiments of steel truss frames which receive constant vertical load and cyclic horizontal load, load-deformation rekationship of truss structures are defined as simplified model diagrams. Using these diagrams earthquake resistance design method of truss structures are proposed.

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This paper developes high order moment standardization method into structural design, and investigates efficiency of the proposed method through numerical calculations. Firstly, a problem in application of the limit state function is shown. The problem is solved by standardizing after application of the limit state function. Furthermore, a reliability index with high order moments in derived with the simpler form than that proposed in the previous paper. The reliability index is defined by substituting k_z into the high order moment standardizing function. k_z is the coefficient that is composed of the mean value and the standard deviation. Secondly, analytical results based on the prososed method are compared with analytical results based on the second-moment method (FOSM, AFOSM method) through numerical calculations. Further, efficiency of the proposed method is shown.

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Mathematical model of nonstationary random excitation is, in many cases for convenience' sake, expressed by the product of a stationary random excitation and an amplitude modulating function. In those cases, spectral content of modulated excitation may differ notably from that of unmodulated. Therefore, amplitude modulation method doesn't seem suitable for the nonstationary random vibration analysis, in which the frequency characteristic of an excitation is taken into serious consideration. In this study, it is verified that the intensity distribution of a nonstationary excitation is dependent on the phase inclination of that excitation. By making use of the probability characteristics of phase inclination, mean and mean square as well as auto-correlation functions of nonstationary random excitation are derived in the explicit form and are applied to the random vibration analysis of SDF linear oscilator.

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It is very important to know how does the local modification of the system affect the natural frequency of the original system. In general, two different approaches are adopted to investigate about this kind of problem. One is the sensitivity analysis of the eigenvalue which is based on Rayleigh's quotient or Jacobi's variation. The another one is the combined dynamical system analysis which is based on the Weinstein's determinant or Kron's method, and by these approaches, a large amount of formulas has been proposed, but when we want to design the system to have a given natural period, these formulas are not enough to use. We need more simple theories and more convenient forms. In this paper, following new formulas are proposed which decide the exact value of added mass Δm or of added spring Δk in order to get the arbitrary natural period. Δm=g_m(T^*, T_i, Ψ_i, C) Δk=g_k(T^*, T_i, Ψ_i, C) where T^* is the given natural period, T_it and Ψ_i are natural periods and mode vectors of the original system, respectively, and C is a connection vector that is decided from which the mass or the spring is added. Simple examples are shown by using these formulas. Some considerations for the limitation of these formulas and some comparisons with other's works are done. Especially, Brameller's formula, Simpson's formula and Hirai's formula are chosen to compare.

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This study deals with round bar reinforced concrete columns designed according to the 1962 AIJ R/C building code. Repair and strengthening procedures and specifications of the columns damaged by earthquakes are presented and their effectiveness is experimentally confirmed. Eight column specimens were loaded to various damage states and repaired or stregthened. Shear span ratio (a/D) of two specimens is 2.0, four specimens 1.0, and two specimens 0.5. Repaired or strengthened specimens were tested again. Test results show that repair and strengthening procedures and specifications presented in this paper are quite effective. Main conclusions are following two. (1) The column damaged can be repaired using epoxy resin and epoxy resin mortar, in case of relatively light damage state. (2) The column damaged in shear failure mode can be strengthened to have much higher strength and much larger deforming capacity than those of former non-damaged column. Newly arranged hoops are quite effective especially.

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In the case of the embedded type colunm-to-footing connections of large-scale steel structures such as thermal power plants and steel manufacture plants, the embedded depth of column is usually less than the depth of column section ; and the base plate is connected rigidly with reinforced concrete footing by anchor bolts. The results of tests and analysis on the fracture mode and the-ultimate strength of this type connections are as follows, i) The footing concrete of the connections has been fractured by punching shear. The fracture modes can be classified into two types, i.e., one is the punching shear fracture of the upper concrete due to the bearing stress between the footing concrete and the upper face of base plate, and, the other is that of the front concrete due to the bearing stress between the stub concrete and the side of the embedded colunm. ii) Based on the mechanism of stress transfer of the connections obtained from above test results, the analytical method of predicting the ultimate strength of the connections has been proposed for each fracture mode of the connections. iii) The proposed analytical method accounts for the effects-of the experimental variables on the ultimate strength and the fracture modes of the connections.

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To clarify the failure mechanism, hysteretic characteristics and load carrying capacity of beam-to-column connections in steel reinforced concrete frames, thirty specimens are tested under monotonic and reversed cyclic loading. Experimental variables are the types of connections ; interior (cruciform), exterior (T-shape) and corner (L-shape) connection, and the ratio of the beam width B_b to the column width B_c ; B_b/B_c = 0, 0.6, 0.8, 1.0. Specimens are designed so as to prevent flexural and shear failure of the members, which connection panels are made of pure steel or steel-and-concrete. The following observations are made in the tests. The failure mode changes from the diagonal tension failure to the diagonal compression failure of concrete, as the type of connection changes from L-shape to cruciform shape, or as the value of B_b/B_c increases. Connections failing in shear show stable hysteresis loops, even though the shear reinforcement is not provided. The strength deterioration is not observed until the shear strain of the connection reaches about 0.02 rad. Diagonal tension cracking strength is not affected by either the type of connection or the value of B_b/B_c. On the other hand, ultimate strength is strongly affected by either the type of connection or the value of B_b/B_c. The ratios of the strength of T-shape and L-shape specimen to the strength of the cruciform specimen are 0.64 and 0.52, respectively. In case of T-shape and L-shape specimens, maximum strengths differ in the positive and negative loading. The shear strength of each type of connection increases with the increase of the value of B_b/B_c. Effective thickness of the concrete panel can be taken equal to (B_b + B_c)/2. The strength of the concrete panel is well estimated by proposed empirical formula (7.4).

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An analytical method to predict the immediate settlement of a sand base footing is discussed in this paper. The summary of the results is shown below. Secant modulus of elasticity has been derived from the relations between stress and strain obtained from triaxial compression tests. This modulus is the expansion of Janbu's experimental equation and varies according to the change of lateral pressure and strain. The value of stress used in calculating the settlement is derived from stresses in ground which have been calculated on the assumption that the base is elastic. The result of calculation is as follows. The settlement of a circular footing goes to 3D (D : the diameter of the footing) but most of settlements are within D. The settlement of a foundation continuous footing goes to 5 B (B : the width of the footing) but most of the settlements are within 1.5 B.

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The estimation method of damage caused by liquefaction due to earthquake is proposed by making use of the great earthquake damage data in the Tokai district, central Japan, where the disasterous earthquakes had been repeatedly occurred in the past. In Nagoya city, western part of Tokai district, damage of wooden houses due to liquefaction is brought in case of the past three destructive earthquakes which are the 1891 Nobi, the 1944 Tonankai and the 1945 Mikawa Earthquake during preiod from 1800 to 1950. The empirical equation of damage estimation is formulated from several factors, such as activity of ground liquefaction, irregularity of ground structure, duration time of seismic waves and strength of houses, which are applied to the sites of ground liquefaction based on literature review. The results are summarized as follows : (1) The severe damage to houses due to earthquake is explained by taking account of the effect of ground liquefaction occurred during earthquakes. Damage due to liquefaction is more than 20 to 40 per cent larger than that caused by the strong ground motion without liquefaction. (2) The correlation coefficient of the damage ratio of past earthquakes in relation to that of calculated value by the empirical equation is 0.929. This equation is [numerical formula] where Y is the damage ratio in percent, S_1 to S_3 are correction for the duration time of seismic waves (see Table 3), G_1 to G_3 are correction for the irregularity of ground structure (see Figure 14). B_1 and B_2 are correction for the individual foundation strength of wooden houses and the strip footing foundation one, respectively. P_1 is the numerical value of liquefaction potential calculated from the comparison of shear strength of sandy soil layers and the maximum acceleration on the ground surface. (3) The estimation of damage ratio for the future great earthquake, occurrence of which is expected in this Tokai district, are more than 15 percents in the area near sea and river basin in Nagoya city. The damage ratio due to liquefaction is more than 3.6 times that caused by the strong ground motion.

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The loads on piles and frequently a combination of verical and horizontal loads resulting in inclined resultant loads. The lateral bearing capacity of piles is infulenced significantly by this inclined loads. Extensive theoretical studies have been carried out on single vertical piles subjected to horizontal loads. However, to date there does not appear to be any theoretical analysis on vetical and batter piles subjected to inclined loading in various soil condition. The first part of this paper, part 1 dealed with the passive-earth-pressure of vertical and batter piles considered the friction between pile surface and soil, and part 2 showed an analysis method for the ultimate lateral resistance of short restrained piles. This paper part 3 show an analysis method for the ultimate lateral resistance of short free headed piles. The after this paper part 4 will deal with an analysis method for the ultimete lateral resistance of intermediate long restrained piles.

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Theoretical solutions on horizontal resistance of pile are introduced by using coefficient of subgrade reaction method based on Winkler's hypothesis. In the process of getting the solutions, the concept of degree of restraint for rotation at pile head α_r and effect of pile length are introduced, i.e., both of boundary conditions at pile head and pile tip are considered. Conclusions from analytical results by these solutions are summarized as follows. 1) Practically, piles, length L of which satisfies the condition βL≧3 are classified into long pile and theoretical solutions on horizontal resistance of infinite length pile can be applied. β is the coefficient shown by Eq. (3). 2) Degree of restraint for rotation at pile head α_r is influensive factor even in long pile case, and is related to bending moment or displacement at pile head in the form of linear function. 3) Not only α_r but also difference of pile length, i.e., boundary condition at pile tip affect considerably stress and displacement of pile in short pile case (β<3). For instance, as regards bending moment at pile head, about 10 % larger value than infinite pile length case appears in the range around βL=1.5 for free or fix condition at pile tip, and 30 to 40 % larger value appears in the range around βL=1.0 for pin condition at pile tip. If both boundary conditions at pile head and pile tip are fix in case of extremely short pile, bending moment distribution of pile becomes similar to case of short column. So that, it's necessary to use the solutions for case of finite length pile by considering boundary conditions at pile head and pile tip. 4) It becomes possible to analyze horizontal resistance of pile foundation mixed with different length piles under the same building, because the solutions shown in this paper cover all the pile length from the finite to the infinite.

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The effects of the vertical, horizontal and diagonal shear reinforcemens and the surrounding frames to the ultimate shear strength of R/C shear walls were discussed based on series of the numerical results obtained by finite element analysis. Also, a macroscopic model was proposed to predict the ultimate strength of R/C shear walls, and it was found that the ultimate strength predicted by this macroscopic model analysis corresponded well with experimental results.

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Static and dynamic properties of space-frame with open-section shear walls subjected to lateral loads is discussed in comparison with the results by the following three kinds of methods. The methods are an exact method by matrix analysis, an approximate analysis by [D]-value method, and a method of plane frame analysis. The main results of this study are as follows : (1) A plane frame analysis leads to include noticeable errors, because it could not accurately estimate the structural characteristics of open-section shear wall. (2) [D]-value method appears to result in fairly good estimations for both static and dynamic behaviors in comparison with the result by the exact method.

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Time dependent deflection analysis by FEM was proposed reffering two way slab. It includes the effects of creep, drying shrinkage and bond creep between the steel and concrete. Using the calculated values of case-study, new simple and practical analysis method was proposed replacing two way slab with one way slab model. Many reports data on building slab investigation were compared with the calculated value by the simple method.

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