Unplanned Construction of a 210 Ft High Temple

A 210′ high temple site was located on a hillock made up of filled up soil. Taking the advantage of site topography terraced construction consisting of the main temple in the centre and rooms on the three sides were planned. The construction progressed without any soil investigations. The paper highlights the problems faced at the stage when the construction had already progressed up to +50 ft. Soil investigations were carried out at this stage. Then, the performance of structures was predicted and possible modifications in the future construction are presented

Performance of a Cement Silo under Quarry Blast

Behaviour of a 67 m tall R.C.C. twin storage-cum-blending cement silo has been studied under blast loads from a nearby limestone quarry. This paper reports the findings of the analytical and experimental studies and verification of the results of analysis by the measurements made on the prototype structure, which agreed within 10%. Acceleration response of the structure were recorded for a blast of 2.61 t having six delays with maximum charge per delay 800 kg. A series of small and large size blasts were conducted to establish relationship between peak ground acceleration and distance from the blast. Non-dimensional acceleration response spectra were also computed for the two large size blasts of 2.61 t and 3.91 t. Only some of the higher modes of the vibration are found to have significant contribution to the response. Further, the measured values response agreed closely with the computed values, indicating rationality of the analysis as well as the relationship developed between peak ground acceleration and distance. Also a damping value of 2% critical has been found to be most appropriate. It is seen that the acceleration responses are dominated by the higher modes of vibration upto the 6th mode while the shear forces and moments are mainly contributed by the first three modes of vibration, the second mode alone contributing 95% to the base shear and 84% to the base moment

Embedment Effect on Foundations under Vertical Vibrations

The dynamic response of the embedded foundation subjected to vertical dynamic loads has been studied through carefully conducted field tests. The block was excited in vertical and coupled modes of vibrations. Four excitation levels were used. Tests, with different embedment depths were carried out. The foundation block was instrumented to monitor dynamic contact pressure at various embedments with specially designed contact pressure cells. Side shear resistances were measured through dynamic shear resistance cells specially designed for the purpose. Also, frequency amplitude characteristics were observed during each test .The analysis of data indicates that as the depth of embedment increases, damping factor, stiffness and in-phase soil mass increase. Dynamic pressure distributions exhibit marked changes with embedment depth. The dynamic shear resistances developed on the vertical side surfaces, vary non-linearly

Stability of Suspension Bridge Anchorage System

The lift side anchor system for a 151 m span suspension bridge over river Alaknanda in Himalayan region was unstable. The gravity type anchor block for the suspension bridge was constructed by cutting the toe of the natural slope. Walls were constructed to retaining the backfill and the anchor block. Slips along the natural slope were frequent. The site lies in an active seismic zone. The paper presents the details of analysis of anchor block, retaining walls and the natural slopes. The analysis is carried out both under static condition and also by taking seismic coefficients. The already constructed retaining walls which were unsafe have been strengthened by designing a composite retaining wall keeping in view the requirements of the client not to demolish any of the already constructed retaining wall

Health of Ammonia Horton Spheres and Foundations – A Case History

Liquid Ammonia is stored under pressure in steel Horton spheres (diameter 17 m) under operating pressures of 5-6 kg/cm2. These spheres are supported on twelve steel columns, concrete pedestals, concrete ring beam and raft or pile foundation depending on the soil conditions. The continuous circular ring beam rests on 72 concrete piles each 45 mm dia and 17 to 20 m long. The second identical Horton sphere is supported on a raft foundation. The two Horton spheres have been subjected to a hydrostatic loading of 1. 7 kg/cm2 and an additional pressure of 7.3 kg/cm2 for performance check. Strains were measured at the crowns, four equatorial points and in six columns. The test results indicate that the spheres and the columns behaved consistent with theoretical values. The concrete in foundations was found to be of good quality corresponding to M20 grade. The settlements under four columns of the fully loaded actual structure were within anticipated limits i.e. 4-6 mm

Damage and Remedial Measures for Buildings on Hill Slopes

The paper deals with details of geotechnical investigations carried out for evaluating the reasons of damage to the buildings resting on hill slopes in northern region of India and also to evaluate the soil parameters for designing retaining walls and other remedial measures for preventing further damage to structures. Three causes of failure were identified namely (i) instability of slopes, (ii) improper design of retaining walls and (iii) differential settlement of structures. Shear strength parameters of the soil mass required for the analysis of slope stability and stability of retaining wall sections have been chosen based on three methods of investigations viz. large scale direct in-situ shear tests, plate load tests and the back analysis method. The stability analysis of various sections of slopes have been carried out and measures for strengthening of slopes have been suggested

Stability of Slopes - A Case History

A Lecture cum-cinema hall was constructed on a terrace developed at the top of a hillock at a site located in the north-eastern part of India. At the time of development of the site, excavated soil was dumped on the slopes and retaining walls were constructed to retain the earth. After the first monsoon, the retaining walls gave way. Further distress in the vicinity of the building was noticed in the subsequent three years. The paper describes the details of the above failure, the investigations carried out and the remedial measures suggested

Enhanced dissolution and bioavailability of gliclazide using solid dispersion techniques

Gliclazide is practically insoluble in water and its bioavailability is limited by dissolution rate. To enhance the dissolution rate and bioavailability the present study was aimed to formulate solid dispersions using different water soluble polymers such as polyethylene glycol 4000 (PEG 4000), polyethylene glycol 6000 (PEG 6000) using fusion method and polyvinyl pyrrolidone K- 30 (PVP K 30) by solvent evaporation method. The interaction of gliclazide with the hydrophilic polymers was studied by Differential Scanning Calorimetry (DSC), Fourier Transformation-Infrared Spectroscopy (FTIR) and X-Ray diffraction analysis. Solid dispersions were characterized for physicochemical properties like drug content, surface morphology and dissolution studies. Various factors like type of polymer and ratio of the drug to polymer on the solubility and dissolution rate of the drug were also evaluated. Pharmacokinetic studies of optimized formulation were compared with pure drug and marketed formulation in wistar rats. The dissolution of the pure drug and solid dispersion prepared with PVP K 30 (1:1) showed 38.3 + 4.5 % and 95 + 5.2 % release respectively within 30 min. Peak plasma concentration of pure drug, solid dispersion (PVP K 30) and marketed formulation was found to be 8.76 + 2.5, 16.04 + 5.5 and 9.24 + 3.6 μg/ml respectively, from these results it was observed that there is two fold increase in peak plasma concentration compared to pure drug. Solid dispersion is an effective technique in increasing solubility, dissolution rate and bioavailability of the poorly soluble drugs.Keywords: Gliclazide; solubility; solid dispersion; pharmacokinetics; peak plasma concentration; half lif