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A Comparative Study on Fly Ash and Bagasse Ash Using as a Sub-Grade Material
Gazi Mohammad Harun-Or-Rashid,
Mohammad Farhadur Rahman,
Abu Bakar Siddique
Issue:
Volume 7, Issue 4, July 2019
Pages:
82-87
Received:
21 May 2019
Accepted:
10 July 2019
Published:
8 August 2019
Abstract: Expansive soil is prone to large volume changes (swelling and shrinking) that are directly related to changes in moisture. So the low bearing strength and high compressibility behavior of soil can cause severe damage to subgrade. In this research the enumeration of the strength of soil by adding different types of ground improvement materials like as fly ash and bagasse ash in order to overcome such type of damages. The California Bearing Ratio (CBR) test to determine the stability of subgrade soil by adding fly-ash and bagasse ash separately at different percentages. The objective of this paper is to study the combined effects of Fly Ash and Bagasse Ash on Maximum Dry Density (MDD), Optimum Moisture Content (OMC), Soaked CBR and Swelling pressure of expansive soil. The effects of molding water content and compaction delay, on soaked CBR of both Ashes stabilized expansive soil have also been studied. CBR tests were performed with fly-ash and bagasse ash separately at different percentage variations with the increment of 2.5% by weight in order to find out which one is most suitable for stabilization of subgrade material. The results show that initially the optimum moisture content (OMC) of soil is 13.5% and for addition of fly ash and bagasse ash separately up to 12.5% it has become in increase up to 19.1% and 15.26% respectively. Initially the CBR value of soil is 6.63%. For addition of bagasse ash up to 10% the CBR value of soil has become in increase up to 13.87% and after then for addition of 12.5% bagasse ash it has become in decrease 13.42%. For fly ash the CBR value for 10% is 15.11%, which is larger than the bagasse ash.
Abstract: Expansive soil is prone to large volume changes (swelling and shrinking) that are directly related to changes in moisture. So the low bearing strength and high compressibility behavior of soil can cause severe damage to subgrade. In this research the enumeration of the strength of soil by adding different types of ground improvement materials like ...
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Evaluation of the Public Housing Projects Role in Contributing to Mitigation of Housing Crisis in Gaza Strip
Nabil El-Sawalhi,
Mohammed Lafi
Issue:
Volume 7, Issue 4, July 2019
Pages:
88-100
Received:
24 June 2019
Accepted:
13 July 2019
Published:
15 August 2019
Abstract: Gaza Strip faces large and accumulating shortfall between the built and needed houses due to a high natural population growth, very high population density, difficult political and economic conditions and a suffocating siege imposed, with a high unemployment rate. This has caused an increase in the ongoing gap between housing demands and supply. The most prominent public housing projects in Gaza Strip implemented during the time period from 1994 to 2017 have been introduced. The aim of this research is to improve the contribution of the public housing projects in alleviating of housing crisis in Gaza Strip. Literature review and questionnaire survey were used. 80 copies of the questionnaire were distributed randomly to experts working in the housing field in Gaza Strip. 73 copies of the questionnaire were received with response rate of 91.25%. The most important result is that the public housing projects and public housing policies have a low rate in contribution to alleviating the housing crisis in Gaza Strip. There is lack of comprehensive, realistic and appropriate public housing policies. In addition to not reviewing and updating the public housing standards which have led to mistakes in the way of choosing the target group of public housing projects. The main obstacles facing the government in solving the housing crisis are lack of housing policies, shortage of economic resources of the government and citizens, shortage of the construction materials, high population density and high population growth rate.
Abstract: Gaza Strip faces large and accumulating shortfall between the built and needed houses due to a high natural population growth, very high population density, difficult political and economic conditions and a suffocating siege imposed, with a high unemployment rate. This has caused an increase in the ongoing gap between housing demands and supply. Th...
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Characteristics and Causes of Water Seepage on Riverside Tunnel Structure and Control Measures in Sandy Pebble Stratus
Zhang Wenhan,
Xu Jianxiao
Issue:
Volume 7, Issue 4, July 2019
Pages:
101-107
Received:
4 July 2019
Published:
27 August 2019
Abstract: The water content and permeability of silt and silt strata are significant in cities of Southwest China, and the seepage of underground passages in cities is unavoidable, which affects normal operation. More serious situation may occur when large-scale water gushing phenomenon and obvious structural deformation appears. After long-term and repeated repairs, water cannot be sealed, and even causes surface subsidence and deformation, voids in ground soil, which cause severe social and economic impacts. Loss. Therefore, it is necessary to formulate effective water shutoff measures for specific seepage projects according to local conditions to ensure that groundwater seepage can be effectively solved or controlled. Taking an underground passage in a city as an example, this paper analyses the causes and characteristics of seepage diseases, explores the specific stratum conditions of seepage location and puts forward control measures. Through detection the effectiveness of the implementation of control measures are verified, which provides reference for the treatment of underground seepage in similar strata.
Abstract: The water content and permeability of silt and silt strata are significant in cities of Southwest China, and the seepage of underground passages in cities is unavoidable, which affects normal operation. More serious situation may occur when large-scale water gushing phenomenon and obvious structural deformation appears. After long-term and repeated...
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Analysis on Influencing Factors of Blasting Vibration Caused by Shallow Tunnel Excavation
Haixia Wei,
Zheng Qu,
Jie Zhu,
Qiangqiang Zhang
Issue:
Volume 7, Issue 4, July 2019
Pages:
108-112
Received:
8 September 2019
Published:
23 October 2019
Abstract: With the widespread construction of urban subway, more and more shallow tunnels will be constructed by blasting, and the problem of blasting vibration will become more prominent. Because of the randomness and variability of blasting source and topographic and geological factors, the propagation mechanism and influencing factors of blasting vibration wave are very complex. Based on blasting-vibration sample data obtained from the established numerical model of blasting excavation in shallow tunnel, the relational degree analysis was carried out for influencing factors of blasting vibration caused by shallow tunnel excavation with method of grey relational analysis. The results of the study are as follows: Among the four related factors, there is no optimal factor, and the maximum charge of one section is the quasi-optimal factor; The charge of the first section is the main factor affecting the peak particle velocity of blasting vibration; The maximum charge of one section is the main factor affecting the main frequency of blasting vibration; The delay interval is the main factor affecting the duration of blasting vibration. Furthermore, the measures to control blasting vibration caused by shallow tunnel excavation were put forward, such as reducing the charge of the first section, reducing the maximum charge of one section and rationally setting up the delay interval. The study has important guiding significance for safe blasting construction in shallow tunnel and scientific control of blasting vibration effect.
Abstract: With the widespread construction of urban subway, more and more shallow tunnels will be constructed by blasting, and the problem of blasting vibration will become more prominent. Because of the randomness and variability of blasting source and topographic and geological factors, the propagation mechanism and influencing factors of blasting vibratio...
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Discussion on Detection Method of Continuous Compaction Control Technology in Filling Engineering
Yu Qi,
Jiang Huihuang,
Gao Mingxian,
Xiang Weiguo,
Yan Xiaoxia,
Wu Longliang
Issue:
Volume 7, Issue 4, July 2019
Pages:
113-120
Received:
8 September 2019
Published:
23 October 2019
Abstract: Compared with the traditional sampling quality detection method, the continuous compaction control technology has significant advantages in real time, full range and comprehensiveness. Therefore, this technology has gradually been widely used in the filling project. However, there are more than ten kinds of continuous compaction control methods, and the applicability of each method is different. Therefore, in order to promote the continuous application of continuous compaction control technology in China. The basic principles of various testing methods for continuous compaction control technology of filling engineering are summarized. The existing continuous compaction control technology testing methods are divided into four categories: (1) compaction method; (2) stiffness/modulus Method; (3) kinetic method; (4) energy method. The calculation process and supporting equipment of each detection method are introduced respectively. The applicability of various methods is analyzed based on the basic theory of various methods. The applicable scope and application suggestions of each detection method are proposed. The results show that the compaction method and energy method can be applied to fine-grained fillers, and the stiffness/modulus method and kinetic method can be applied to coarse-grained fillers and asphalt mixtures. According to the specific engineering conditions, the selection of suitable testing methods for continuous compaction control can obtain satisfactory application results.
Abstract: Compared with the traditional sampling quality detection method, the continuous compaction control technology has significant advantages in real time, full range and comprehensiveness. Therefore, this technology has gradually been widely used in the filling project. However, there are more than ten kinds of continuous compaction control methods, an...
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