Tạp chí KHCNXD

Tạp chí Khoa học Công nghệ Xây dựng số 2/2017

Ngày tạo : 22/09/2017

Tính toán khả năng chịu cắt của dầm bê tông cốt thép theo TCVN 5574 : 2012, d,ownload

TS. NGUYỄN ĐẠI MINH, ThS. NGUYỄN MẠNH CƯỜNG, ThS. NGÔ QUANG HƯNG

Phương pháp phần tử biên tính nội lực và chuyển vị hệ dầm trên nền đàn hồi theo mô hình winkler, download

TS. VŨ THỊ BÍCH QUYÊN, TS. ĐỖ XUÂN TÙNG, KS. NGUYỄN THẾ THỊNH

Phân tích sự làm việc kháng chấn của kết cấu bến bệ cọc lai ghép trọng lực, download

TS. NGUYỄN THÀNH TRUNG

Quy trình quản lý chất lượng thi công sàn U - Boot Beton tại Việt Nam, download

TS. NGUYỄN HOÀI NAM

Ảnh hưởng của hàm lượng tro bay đến sự phát triển cường độ chịu nén của bê tông, download

TS. NGÔ SĨ HUY, ThS. LÊ THỊ THANH TÂM, TS. HUỲNH TRỌNG PHƯỚC

Ứng dụng phương pháp số bình phương nhỏ nhất để xác định các chỉ tiêu cố kết của đất bằng phương pháp Asaoka khi xử lý nền đất yếu, download

ThS. TRẦN THỊ THẢO

Nghiên cứu hiện trạng và nguyên nhân sạt lở bờ phải sông Hồng, đoạn Ba Vì – Sơn Tây, thành phố Hà Nội, download

TS. DƯƠNG THỊ TOAN, ThS. NGUYỄN VIỆT HÀ

Một số điểm mới trong dự thảo TCVN 5574 : 2017, download

TS. LÊ MINH LONG

Hệ thống Quy chuẩn kỹ thuật Quốc gia và Tiêu chuẩn Quốc gia trong ngành Xây dựng, download

ThS. TRƯƠNG THỊ HỒNG THÚY

ABSTRACT

Analysis of reinforced concrete  beams under shear based on TCVN 5574:2012 (pp.3-5)

Dr. NGUYEN DAI MINH, MEng. NGUYEN MANH CUONG, MEng. NGO QUANG HUNG

At present, shear analysis of reinforced concrete beams based on the Vietnamese standard TCVN 5574:2012 is considerably complicated for both of the design and verification works. To establish the calculation algorithm of the shear design integrated into the structural analysis software, it is required the computational steps and formulation in the simple way and easy application. Therefore, this paper presents the procedure for the analysis of reinforced concrete beams under shear based on TCVN 5574:2012 with simple formulations that are easily understandable and applicable. This procedure can be well integrated in structural analysis software such as ETABS, SAP 2000 etc., and be a good applications for both the design and verification works.

The boundary element method for internal force and displacement calculation of beams on winkler foundation model (pp. 6-12)

Dr. VU THI BICH QUYEN, Dr. DO XUAN TUNG, Eng. NGUYEN THE THINH

This paper is to presents the solution of beams on elastic foundation using boundary element method. Based on Winkler foundation, the deflection of the beam is solution of four-order differential equation. Then the internal forces and displacements of the beam system are calculated by using boundary element method.

Analysis of seismic behavior of hybrid gravity type pier structure for quay wall (pp.13-19)

Dr. NGUYEN THANH TRUNG

The hybrid gravity type pier structure is a new structural type has some good advantages such as a fast construction, an economical cost and a good behavior. It is applied for deep water berths and is of a special importance. Therefore, in the detail design step, a seismic calculation must be conducted comprehensively and exactly. In this study, 2D numerical models using finite element method for three structural types consist of the hybrid gravity type pier and the typical gravity caisson and pile pier structures were conducted in this study. Their responses under an input ground motion were compared and evaluated to expressseismic advantages and disadvantages of this structure.

Qualilty management procedure of Beton U-boot Slab construction in Viet Nam (pp.20-30)

Dr. NGUYEN HOAI NAM

Beton U-Boot Slab is the hollow slab using recycled porypropylen replacing for the area of concrete slab which does not mainly bear the load. As a result of this: the weight of the slab is reduced, more flexible architectural spaces, easy for site plan selection. However, there is no construction procedures, acceptances and quality managements in details. The author of this article proposes construction quality management procedures for this type of slab.

Effect of fly ash content on the compressive strength development of concrete (pp.31-36)

Dr. NGO SI HUY, MEng. LE THI THANH TAM, Dr. HUYNH TRONG PHUOC

The production and use of ordinary Portland cement in concrete havea significant effect on the surrounding environment by generating a large quantity of carbon dioxide and depletingthe natural resource. The objective of this research is to partially replace ordinary Portland cement in concrete mixture with fly ash, which isa by-productfrom thermal power plant. The effect of fly ash content on compressive strength developmentof concrete is investigated. Three mixtures were designed with 10%, 20%, and 30% fly ash replacement for cement compared with a control mixture. Test results indicate that the workability of fresh concrete increases and the unit weight of concrete reduces with increasing fly ash content. The compressive strength of concrete with10% fly ashis the highest, while that ofconcrete with 30% fly ashis the worst. Concrete with 20% fly ash has lower compressive strength than control concretebefore 28days; after 56days it gets higher.

Using the Least square principle for consolidation prediction of soil by Asaoka method during soil improvement process (pp.37-42)

MEng. TRAN THI HAO

Asaoka method [Asaoka 1978] for prediction of total settlement of soil during soil improvement process by surcharge and vertical drain is well accepted by geotechnical engineering community and now is widely used in Viet  Nam due to its simplicity and relatively accuracy. During the inspection process of National Acceptance Committee (NAC) in various projects it is usually observed that the soft soil treatment reports present consolidation parameters without accuracy estimation. Consequently the experts of NAC and design consultant do not know the realibity degree of the data being provided. This paper presents a new algorithm for calculation of predicted total settlement based on Least Square Method (LSM) – the best suitable method for treatment the monitoring data. In additionthe algorithm based on proposed method provides also formula for accuracy estimation giving mean square error of all parameters computed. The calculation procedure is illustrated by a numeric example with observation series taken from consolidation report of animportant project in Viet Nam that has already been processed by classical Asaoka method. The coincidence of allresults calculated by both two methods prove the correctitude of proposed algorithm.

Assessment the current status and relate factors affecting to Red river bank instability in Ba Vi – Son Tay, Hanoi area (pp.43-54)

Dr. DUONG THI TOAN, MEng. NGUYEN VIET HA

Riverbank instability has been being happened along Red riverbank, specially in Ba Vi – Son Tay (Km 0 – Km 32). This paper is to clarify current status and assessment relate factors causing Red riverbank instability in Ba Vi – Son Tay to build database for suggesting protected solutions. Based on analysis relate factors and using Geoslope, riverbank from Ba Vi to Son Tay can be divided into types: (1) Riverbank area are strongly eroded and slided including Thai Hoa (Km0-Km1+500), Chu Minh (Km21+600 - Km22+700), Dong Quang (Km24+30 -Km24+800),Đường Lâm (Km 26+500 - Km 29+350). River channel has direction forward to riverbank, causing greatly erosion and riverbank slide. The main reason affecting to riverbank are water flow erosion and bed river sand mining which cause river bed lower. If the bed river caused lower 1-1.5m, the riverbank failure will be happen; (2) Riverbank in Co Do, Phu Chau, Phu Cuong (Km9 đến Km21), Cam Thuong (Km 26+200 đến Km26+500), Son Tay (Km 26+500 đến Km 29+350) have large alluvial area. Riverbank is not affected directly from river water flow. Rain fall and seepage transient are main reason causing riverbank instability. The higher intensity of rain, the quickly riverbank instability is. Moreover, the small rainfall in longterm also causes damage of riverbank.

The some news in new version TCVN 5574:2017 (pp.55-61)

Dr. LE MINH LONG

The design standard on concrete and reinforced concrete structures has been introduced about 15 years ago and will be expected to supersede by new version TCVN 5574:2017. This paper introduces some new aspects to be concerned in new version TCVN 5574:2017.

National technical regulation and vietnam standards in the construction field (pp.62-68)

MEng. TRUONG THI HONG THUY

System of National Technical Regulation (QCVN) and Vietnam's standards have always been associated with the development of the construction sector. Until now, this system has basically met the developing requirements of the sector. However, shortcomings in the process of management, compilation and application still remain in the system. This article presents current situation of the system of National Technical Regulation (QCVN) and Vietnam's standards and put forward some solutions to improve the quality of standardization of this system in the construction field.

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