Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Gypseous Soil


Study The Effect of Al-Sugar Factory’s Waste on The Engineering Properties of Gypseous Soil

K.N. Al-safaar; Anas. F.K; A.M. Ialkiki

Engineering and Technology Journal, 2014, Volume 32, Issue 8, Pages 292-303

This study investigates the possibility of using the industrial waste material of Al-sugar factory to improve the engineering properties of Gypseous Soil which taken from Baiji area. This soil can be classified as a silty soil with low plasticity and high gypsum content (35% gypsum). The investigated soil was treated with industrial waste (most of its composition is hydrated lime) using (1,3, 5 and 7 %) by dry weight of the soil. The results indicated that the engineering properties improved considerably.
The soil become non-plastic if (5%) of waste is used. The industrial waste increases the unconfined compressive strength and the effective shear strength parameters (angle of internal friction ( ) and cohesion (c`)).
The results of consolidation test showed that the compression Index (cc) and coefficient of consolidation (cv) decreased when the soil was treated with industrial waste. It also has this waste to reduce the effect of leaching process on the compressibility and permeability of the soil.
Accordingly, the industrial wastes may be considered as an advantageous in effect to the engineering characteristics of gypseous soil.

Assessing the Dynamic Behavior of Asphalt Stabilized Gypseous Soil

Mahmood D. Ahmed

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 822-841

The study presents the test results of stabilizing gypseous soil embankment obtained from Al- Faluja University Campus at Al-Ramady province. The laboratory investigation was divided into three phases, the physical and chemical properties; the optimum liquid asphalt (emulsion) requirements (which are manufactured in Iraq) were determined by using one dimensional unconfined compression strength test. In the first phase , the optimum fluid content was 11% (6% of emulsion with 5% water content). At phase two, the effect of aeration technique was investigated using both direct shear and permeability test. At phase three, a laboratory soil model of dimensions 50x50x30 cm was used as a representative of gypseous soil; pure soil, and asphalt stabilized soil have been compacted in five layers after practicing an aeration technique at maximum dry density (modified compaction) cyclic loading test was carried out on four gypseous soil models, two of them were pure soil under (dry and absorbed condition), and the other two were stabilized with emulsion also under (dry and absorbed condition). The impact of charging the hydraulic conductivity due to asphalt stabilization was investigated and the vertical deformations were determined using LVDT.
For the pure soil in dry condition the vertical settlement at the top surface was (7.45 mm) at (157 load cycles), while for pure soil model under absorbed condition, the water was raised to the surface in three days , so the vertical settlement at the top surface was (12.5 mm) at (29 load cycles), this means that the pure gypseous soil under absorbed condition show reduction in strength by(85%).
When the stabilized soil is in dry condition, the vertical settlement at the top surface was (9.75 mm) at (911 load cycles), while the soil was stabilized and subjected to water absorbed for seven days. The water stopped rising at second layer which is the same inlets level from the bottom, and the vertical settlement was (10.47 mm) at (897 load cycles), so there is no change in strength at failure.

Stability Behavior of Lime Stabilized Gypseous Soil

Abdulrahman Aldaood; Marwen Bouasker; Amina A Khalil; Ibrahim Al-Kiki

Engineering and Technology Journal, 2013, Volume 31, Issue 20, Pages 324-338

In arid and semi-arid zones, gypsum (CaSO4.2H2O) is one of the soluble of the common minerals that found in soils. In Iraq, gypseous soils is a worldwide stability problem that causes extensive damage upon wetting, and occur in certain areas characterized by variation of climatic conditions. The results of the stability behavior of lime stabilized gypseous soil where present in this paper under different tests. These tests were erosion, leaching and soaking. Erosion test was conducted under different variables such as water temperature, water velocity and flow duration. The soil used in this study was taken from a site near Al – Hader district about (80 km) from Mosul city. Its main geotechnical index properties are liquid limit is (46%), plastic limit (22%) and specific gravity is 2.58. The amount of the gypsum was 20%. The soil samples were treated with optimum lime percent (4%) depending on the Illinois procedure. A gypseous soil with 20% gypsum content was used and stabilized with 4% lime. All stabilized soil samples were cured for 2 days at 490 C. The results indicate that, the loss in weight increased for samples subjected to the flowing water, further increase in weight losses with increasing flow duration. High water velocity causes increasing in weight losses and loss in gypsum content , more loss in weight and more loss in gypsum content, for all values of flow duration and water temperature. Unconfined compressive strength decreased during the soaking process and further decrease in strength with increasing soaking duration. The leaching effect causes a continuous increasing in the permeability value of unstabilized soil samples, while it has an insignificant effect on the permeability of lime stabilized soil samples. Leaching

is a time-dependent process. The results showed that the pH values of natural and lime stabilized soil samples decreases during leaching process.

Prediction of Square Footing Settlement under Eccentric Loading on Gypseous Soil through Proposed Surface for Dry and Soaked States

Bushra S. Z. Albusoda; Abdul-Kareem E; R. S.Hussein

Engineering and Technology Journal, 2013, Volume 31, Issue 20, Pages 217-237

Gypseous soils as any other soils deform under loading, this deformation differs greatly between its dry state and its soaked state. This deformation also differs when the loading is applied with eccentricity.
An experimental work was conducted on a square footing model (100 mm  100 mm) above gypseous soil 450 mm thick. Loading was applied at the center of the footing (e/B = 0) and at an eccentricity of (e/B = 0.05, 0.1, 0.15, 0.2) for its dry state and its soaked state. Settlement was obtained at the center and at the base soil of the footing for each state.
The data obtained was normalized and a proposed surface was obtained for each of the two states (dry and soaked) and at two places (center and edge). Four proposed equations were obtained represented four cases of research i) Dry center, ii) Dry edge, iii) Soaked center, and iv) Soaked edge. The four equations showed very good agreement with the data obtained from the experiment.
Artificial Neural Network model was also used to obtain a neural network representing the proposed surface for the abovementioned four cases and also a very good agreement was obtained.
It is concluded that a proposed surface for the central and eccentric loading on square footing for gypseous soil showed a good agreement with the experimental data and therefore may be used for settlement prediction.