Road tunnel excavation often traverses coal strata, which is at risk of firedamp explosion that usually results in disaster. Airtight concrete grouting is popularly used in this kind of tunnel project. Based on the es...Road tunnel excavation often traverses coal strata, which is at risk of firedamp explosion that usually results in disaster. Airtight concrete grouting is popularly used in this kind of tunnel project. Based on the essential theory of mechanics of fluids in porous media, the principle of improving concrete airtight property and its influential factors are investigated. The proportioning tests and monitoring method for airtight concrete are introduced, which is illustrated by a case study applied to the project of the Huayinshan Tunnel. It is proved by engineering practices that the achievement of this research work is beneficial to tunneling project across coal strata.展开更多
Small H-beams such as the No.14-20 I-steel can be inserted into soil-cement retaining walls to form small H-beam soil-cement compound walls, functioning both as a retaining wall and a cutoff wall for braced structure ...Small H-beams such as the No.14-20 I-steel can be inserted into soil-cement retaining walls to form small H-beam soil-cement compound walls, functioning both as a retaining wall and a cutoff wall for braced structure excavations. Being different from the mixed soil-cement wall （SMW）, the interaction between soil-cement and small H-steel is very good. We have carried out a series of bending experiments on small H-beams in soil-cement model compound beams to study the mechanism of interactions. The results show that the interaction between H-beams and soil-cement is very good, whether the H-beam is single or double. Joint forms of double H-beams at one end have little effect on both the contribution coefficient and on ultimate deflection before cracking. But after cracking, the joint forms greatly affect the contribution coefficient. We conclude that the rigid joint girder for double H-beams is a better choice in oractice.展开更多
With rapid development of PetroChina＇s Qinghai Oilfield, engineering construction quality becomes more and more important in infrastructure construction of the oilfield. Generally speaking, engineering construction q...With rapid development of PetroChina＇s Qinghai Oilfield, engineering construction quality becomes more and more important in infrastructure construction of the oilfield. Generally speaking, engineering construction quality is related both to national economic development and safety of people and assets. To turn a design map into a materialized object, the construction project involves a large number of elements, such as design, materials, machinery, landform, geological factors, meteorological factors, construction process, technological measures and supervision system. Therefore, quality control holds the key to a construction project.展开更多
基金Funded by the Doctoral Foundation of the Ministry of Education of China (2000061115)
文摘Road tunnel excavation often traverses coal strata, which is at risk of firedamp explosion that usually results in disaster. Airtight concrete grouting is popularly used in this kind of tunnel project. Based on the essential theory of mechanics of fluids in porous media, the principle of improving concrete airtight property and its influential factors are investigated. The proportioning tests and monitoring method for airtight concrete are introduced, which is illustrated by a case study applied to the project of the Huayinshan Tunnel. It is proved by engineering practices that the achievement of this research work is beneficial to tunneling project across coal strata.
文摘Small H-beams such as the No.14-20 I-steel can be inserted into soil-cement retaining walls to form small H-beam soil-cement compound walls, functioning both as a retaining wall and a cutoff wall for braced structure excavations. Being different from the mixed soil-cement wall （SMW）, the interaction between soil-cement and small H-steel is very good. We have carried out a series of bending experiments on small H-beams in soil-cement model compound beams to study the mechanism of interactions. The results show that the interaction between H-beams and soil-cement is very good, whether the H-beam is single or double. Joint forms of double H-beams at one end have little effect on both the contribution coefficient and on ultimate deflection before cracking. But after cracking, the joint forms greatly affect the contribution coefficient. We conclude that the rigid joint girder for double H-beams is a better choice in oractice.
文摘With rapid development of PetroChina＇s Qinghai Oilfield, engineering construction quality becomes more and more important in infrastructure construction of the oilfield. Generally speaking, engineering construction quality is related both to national economic development and safety of people and assets. To turn a design map into a materialized object, the construction project involves a large number of elements, such as design, materials, machinery, landform, geological factors, meteorological factors, construction process, technological measures and supervision system. Therefore, quality control holds the key to a construction project.
