Kisii is County of one thousand hills and contain infrastructure such as roads building, Bridge etc, some of these hills provide an unstable slope which need to be retained so the earth retaining wall and slope treatment is one solution of these unstable slopes is why it is on slope which is on located near road Keroka- Nyangusu Road in Nyamache district, Nyamache Sub- County Hospital in Nyanza Province. The main objective of this research is to design retaining wall for to retain soil near road as better solution. To achieve the goals, some analyses have been done and the software most used were Google earth, Auto CAD and Microsoft word and excel. In addition, laboratory tests such as direct shear test to measure the shear strength parameters where cohesion and friction angle obtained showed that the soil is not cohesive. According to the result found, the analysis and design of retaining wall have been made. The reinforced retaining wall has been designed, and it has been analyzed and design for stability requirements, the lateral earth pressure, checking against overturning, sliding and bearing capacity have been verified and earth retaining wall is found to be stable in the proposed location; the cohesion obtained is 0KN/m2, unit weight of soil is 18.9KN/m3 and friction angle of 440 and safe bearing capacity is 600kN/m2;safety against sliding 2.4 >1.5 and factor of safety against overturning4.36>2andfactor of safety against bearing capacity failure Qmax=158.62 KN/m2<qall where < 600 KN/m2 the total cost of this project of 50m length and 7m height.

This project entitled “Structural design of four-story multi-shopping commercial block in Kisii Town”. The objective the research was to conduct a technical detail and study on the implementation of Structure design of proposed four story commercial building in Kisii Town in order to solve the problems of our country to fit in vision of land use. Therefore, conducting this research project could be a sustainable solution to the above-mentioned problems. During this research, the analysis of structural elements was made by combining manual analysis, ArchiCAD 18 & Atlantis software for providing architectural plans, arcGIS software for creating and using maps, compiling geographic data, analyzing mapped information, dynamic cone penetration test for determining allowable bearing capacity of the soil, PROKON software for analyzing and designing of structures. The architectural drawings, analysis and the design of all elements of structure, cross sections and reinforcements were calculated. The study revealed that building dimensions are (21.30m*25.60m) and the minimum requirements steel bar in slab at the top four steel bars of ten diameters (4Ø10mm/m), bottom three steel bars of eight diameters (3Ø8mm/m). Beam at top four steel bar of twenty five diameters (4Ø25mm), bottom (4Ø20mm). For the column ground floor (8Ø25mm), first floor (8Ø20mm), second floor (8Ø14mm) and last (4Ø12mm), stairs (4 Ø 12), foundation (5Ø16mm)