Tạp chí Khoa học CNXD - Số 3/2005 (132)
Ngày tạo : 15/07/2015
Tạp chí Khoa học CNXD - Số 3/2005 (132)
Một phương pháp tính độ tin cậy của công trình có biến mờ
tham gia
GS.TS. Nguyễn Văn Phó; ThS. Nguyễn Đình Xân ; KS.
Nguyễn Thạc Vũ
Xử lý các chuỗi thống kê trong
nghiên cứu thực nghiệm
TS. Nguyễn Xuân Chính
Một cách tính độ tin cậy công trình
chịu tải trọng gió ở khu vực Khánh Hòa
ThS. Lê Đức Vinh
Một số vấn đề về ổn định của vỏ á
trụ mỏng
GS. TSKH. Amoxov A.A.; KS. Cao Duy
Khôi
Một số kết quả nghiên cứu và ứng
dụng vữa tự chảy có tính năng chống ăn mòn clorua cao
ThS.
Nguyễn Nam
Thắng; TS. Phạm Văn Khoan
Một số sửa đổi của tiêu chuẩn Nga
trong việc xác định tải trọng động đất
TS. Từ Đức Hoà
Hệ toạ độ quốc gia Việt Nam và
những lưu ý khi sử dụng trong thiết kế và thi công xây dựng công trình
TS. Ngô Văn Hợi
Về sử dụng tiêu chuẩn TCXD 239:2000
TS. Nguyễn Đức Thắng
Một cách tính tối ưu kết cấu dầm
cứng gia cường bằng hệ thanh khớp chịu tải trọng động với ràng buộc xác suất an
toàn
PGS. TS. Lê Xuân Huỳnh; ThS. Trần
Việt Anh
Nghiên cứu chế tạo bê tông cốt sợi
thép phân tán
TS. Trần Bá Việt
A new method for fuzzy
reliability analysis of structures (pp. 3-7)
Prof. Dr. Nguyen Van
Pho, MEng. Nguyen Dinh Xan and Eng.
Nguyen Thac Vu
In 1965, Zadeh introduced fuzzy sets
theory. Subsequently, the theory and the mathematics of fuzzy sets were fleshed
– out and applied in many research.
In 1999, Li Bing presented a
practical engineering method for fuzzy reliability analysis of mechanical
structures. In 2003, Qimi Jiang presented a numerical algorithm of fuzzy
reliability. All these studies considered for element only.
In this paper, the authors propose a
new method for determining the reliability of structures (which consists of
many elements), in which three types of variables: deterministic, random and
fuzzy are included.
The novel method, Monte–Carlo
simulation technique, finite element analysis and linear regression are used.
For reliability assessment, in this
paper the authors used model of fuzzy stress–random strength, but it can apply
for random stress- fuzzy strength or fuzzy strength–fuzzy stress models.
A numerical example is given to
illustrate the mentioned method.
Analysis of
statistical series in experimental study (pp. 8-10)
Dr. Nguyen Xuan Chinh
As far as we all know, when
analyzing experimental data, the experimental distribution curve is different
from the theoretical one. Normally, with a set of data, an experimental curve
can be set up. The question put forward is that, for which theoretical curve
that experimental curve is indicated ? and vice versa, which theoretical curve
indicates/reflects the obtained experimental one?
The "Smoothing" problem of
statistical series is the problem of finding out the theoretical distribution
one so as it reflects well the experimental function.
This paper presents the analysis of
statistical series in experimental study by solving the "Smoothing"
problem, namely, in the known theoretical curve layers in which each curve
depends on one parameter, we choose the most suitable parameters so that the
correspondence between theoretical and statistical distribution is the best.
A method for
calculating reliability of structures subject to wind load at Khanh Hoa
province (pp.11-14)
MEng. Le Duc Vinh
This paper presents a method for
calculating the reliability of structures subject to wind load. Wind load is
calculated according to Vietnam
standard TCVN 2737-1995 and hydro-meteological data monitored at Nha Trang city
during the last 10 years.
The safety obtained when calculating
according to TCVN 2737-1995 is higher than that obtained when calculating
according to hydro-meteological data monitored at Nha Trang. An example
illustrated is the calculation of reliability of a wall panel subject to wind
load.
Some questions on the
stability of thin quasi-cylindrycal shell (pp.15-21)
Prof. D.Sc. A Moxov A.
A, Eng.
Cao Duy Khoi
Quasi-cylindrycal shells (the thin
shell that approximates to cylindrycal one) can be utilized in many various
structures such as: material storage tanks, silos, roofs of buildings, cladding
walls, aero plane covers or the cover of machine-tool. In this paper, the
authors presents a study on the stability of thin quasi-cylindrycal shell.
Some research and
applied results on self-leveling mortar with high performance against
chloride-induced corrosion (pp.22-26)
MEng. Nguyen Nam Thang, Dr.
Pham Van Khoan
Chloride-induced corrosion of
reinforcement in RC structures is a common phenomenon and is considered to be
the main cause that damages Vietnam
marine RC structures. Techniques and materials are the essential solutions for
solving this problem. And, pouring self-leveling mortar with high performance
against chloride-induced corrosion is regarded as an effective anti-corrosion
technique. In this paper, the authors presents some research and applied
results of this technique in repair and rehabilitation of some RC structures
damaged due to chloride-induced corrosion.
Some modified
parameters in Russian "Civil codes and Rules of SNIP II-7-81 - Construction
in seismic area". (pp.27-32)
Dr. Tu Duc Hoa
With the focus on dynamic
coefficient b and other parameters such as K1, K2 and Ky,
this paper presents the most important differences between various versions of
Russian Civil Codes and Rules SNiP II-7-81 (issued in 1981), SNiP II-7-81*
(1995) and SNiP II-7-1981* (1999). Interesting differences are: on the 2nd
and the 3rd versions mentioned above, the period of proper
oscillations Ti which is less than 0.1s was considered and the
correlative values of b were smaller than that in the first ones; In addtition,
the thickness of soil layers was considered in the version issued in 1995 but
it is not considered in the first and the last version.
The Vietnam State
System of Coordinate and attentions required to be paid when applying it to
design and construction (pp.33-36)
Dr. Ngo Van Hoi
The paper presents the most
important feature of the State System of Coordinate (SSC), that is the
deformation of all details presented on drawings in SSC. This uncomfortable feature
might cause a lot of troubles when executing the building constructions if SCC
is used for design. In this paper, the author provides readers with conditions
to check the compatibility between dimensions of the detail on the ground
surface and those shown on drawings and the way to make them being compatible.
On the application of Vietnam
standard TCXD 239:2000, Heavy concrete - guide to assessment of concrete
strength in existing structures (pp.37-39)
Dr. Nguyen Duc Thang
Viernam standard TCXD 239:2000,
Heavy concrete - guide to assessment of concrete strength in existing
structures was developed and issued for application since 2000. This is one of
the first standards of Vietnam
construction standard system that presents in details on the method of organization,
selection, testing and assessment of concrete strength in existing structures.
However, it is required to be modified for a more accurate application. This
paper introduces the way to convert concrete strength of drilled concrete core
sample to the cubic one and principles for evaluating of concrete strength at
building structure.
An optimal method with
safe probability restraints of the beam stiffened by hinged bar structures
under dynamic loads (pp.40-43)
A/Prof. Dr. Le Xuan
Huynh, MEng. Tran Viet Anh
One of the combinative structural
forms is the structure which is formed by the beam stiffened by hinged bar
structures. In this paper, the authors propose an optimal method with safe
probability restraints of the beam stiffened by hinged bar structures under
moving loads that depend on the time by the harmonize function. The loads,
material intensity and geometrical dimensions are random values with the
standard distribution and statistical independence. Content of the method is
determination of the optimal criterion for the problem with two probability
restraints by using the Lagrane method. This study used the sensitive analysis
to change the cross-section area of the structural members. The analysis of the
stress-strain relationship of the structure was carried out by the Finite
element method.
Studying for
production of scattered fiber reinforced concrete (pp.44-49)
Dr. Tran Ba Viet
When constructing of high way,
bridge deck, runway of the airport,.. in addition to high strength requirement,
concrete needs to meet the other requirements such as: strain-resistance under
loads, wear-resistance, control of cracks and impact resistance. The type of
concrete that can meet all the above requirements is the scattered fiber reinforced
concrete. This concrete is self-leveling, high-strength concrete that can be
self-filled up.
This
paper presents some results on a study for production of self-leveling,
high-strength scattered fiber reinforced concrete for the utilization purposes
mentioned above.
