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Several methods have been proposed for estimating the actual tensile forces in metallic tie-rods inserted into the masonry arches and vaults of historic buildings. Static and dynamic methods based on the experimental measurement of the vertical displacements caused by concentrated loads, accelerations, and the fundamental frequencies and periods of free vibrations have been applied to arrive at a more precise evaluation of the axial tensile forces acting on the tie-rod under examination. Each of these methods, with its corresponding experimental procedure, presents different advantages and disadvantages with regard to operating procedures, equipment requirements, and accuracy range in the determination of tie-rod stress. In this paper the writers propose a simple method and experimental procedure based on a single static test. The reference structural system consists of a bending moment-resistant tie beam with unknown restraint conditions at its ends. Therefore, the proposed method does not require any as...

Adhesives can be used to form load-bearing joints in timber structures, both in repair and in new-build applications. An efficient and cost-effective method of making joints is to use rods or dowels, bonded into pre-drilled holes in timber elements, for transferring structural loads between such elements. This paper reviews the important issues in bonded-in rod technology, the adhesives and reinforcing materials used, the results of theoretical and experimental studies, and the steps involved in design and specification.

Loop anchorages are an effective means of providing anchorage for tie reinforcement when detailing discontinuity regions in reinforced or prestressed, precast concrete members using strut and tie models. However, the ACI Building Code does not contain guidance on the use of loop anchorages. An experimental study on the effectiveness of loop anchorages when subject to various levels of compression across the plane containing the loop is described in this paper. Based on the data obtained, design proposals are made for 180-degree loops in Nos. 4, 5, and 6 reinforcing bars with the minimum bend diameter allowed by the ACI Code. Numerical design examples illustrate the proposed design method

The third general cargo berth at Paradeep Port situated on the east coast of India consists of a diaphragm wall anchored to a deadman diaphragm wall by tie-rods. In addition, the diaphragm wall is connected to two rows of large-diameter vertical piles by a rigid deck system. The deck system being rigid and tie-rods flexible, the lateral loads are shared between the piles and the deadman diaphragm wall. To assess the load sharing, forces in the tie-rods were measured before and after dredging. The results obtained were compared with those of a finite element analysis of the structural system using beam elements for the diaphragm walls, piles, and beams, and boundary elements for the soil medium. The measured tie-rod forces compared very well with the analytical result and confirmed that a substantial portion of the lateral load was transferred to the piles. Based on the studies, the design of another berth in the vicinity was modified to retain the vertical piles and eliminate the deadman diaphragm wall and tie-rodd, resulting in substantial savings in cost and time.

A soil-reinforcement load transfer model was developed by the authors1 to simulate the response of the reinforced soil material to triaxial compression and direct shearing. This paper presents the application of the proposed model for the numerical analysis of direct shear tests on sand samples reinforced with different types of tension resisting reinforcements. A parametric study is conducted to evaluate the effect of the mechanical characteristics and dilatancy properties of the soil, extensibility (elastic modulus) of the reinforcements, and their inclination with respect to the failure surface on the response of the reinforced soil material to direct shearing. An attempt is made to verify the proposed model by comparing numerical test simulations with experimental results reported by Jewell,2 and Gray and Ohashi.3 Comparisons of predicted and experimental results illustrate that the model can provide adequate simulations of the response of the reinforced soil material to shearing. In particular, it allows an evaluation of the effect of soil dilatancy (or contractancy), and extensibility of the reinforcement on tension forces generated in inclusions during shearing.

A calculation model for estimating static behavior when a double sheet‐pile wall structure is subjected to horizontal force is proposed, and a comparison is made between the results of calculations and those of model tests to examine the validity of the calculation model. The calculation model is based on the theoretical solution obtained by assuming that the portion of the structure above ground level is a composite of sheet piles and sand fill and that the portion below ground level consists of sheet piles receiving horizontal resistance from the ground, taking into consideration the elasto‐plastic characteristics of the sand fill and the subsurface soils. The calculation results show good agreement with the test results and indicate that the calculation model can be effectively used for predicting the deformation of the wall, the bending moment of the sheet pile, and the tension of the tie‐rod, which are the most important items for structural design.

The results of model tests of 18 ground anchors vertically buried in sand are described in this paper. Also described are tests on half‐section model anchors which were tested to observe movement and behavior during uplift loading of the soil surrounding the anchors. Comparison tests were done to determine the influence of factors such as diameter, fixed anchor length, and buried depth on the uplift capacity of anchors. Two types of failures, deep and shallow, were observed in the tests. The tests showed that top resistance and skin resistance did not occur simultaneously. Peak skin resistance required very little anchor movement, while peak top resistance required substantially more movement. It is concluded that equations currently used to estimate anchor capacity by adding peak skin and top resistance should be modified. Based on the results of the model tests, and confirmed by field tests, an equation was developed for estimating uplift capacity and displacement of anchors.

In this paper, a comprehensive model for the behavior of jointed rock masses reinforced by passive, fully-grouted rock bolts is presented. The model is based on an “equivalent material” approach in which the influence of rock joints as well as rock bolts is distributed throughout the rock mass. A typical problem of a jointed rock slope has been analyzed and factors of safety against collaspse have been computed using the Finite Element Method. It is shown that the dilatancy of rock joints and the orientation of rock bolts are the most important factors in determining the effectiveness of passive, fully-grouted rock bolts.

Numerical analysis was carried out on earthquake-induced displacement of anchored bulkheads. The permanent displacement of several meters experienced in liquefied areas during the Niigata earthquake was large enough to damage the functions of nearby structures. Since the conventional methods of predicting seismically-induced displacement could not deal with thin sheet-pile walls subject to liquefaction, they were modified and improved. The new method analyzed the limit equilibrium of a backfill soil wedge under the action of pseudostatic seismic force, and calculates the critical acceleration of an earthquake which is required for the sliding mechanism to be activated. By following Newmark's sliding block theory, the seismic acceleration in excess of the critical value is integrated twice with time so that permanent displacement may be obtained. Effects of pore water pressure development is taken into account by allowing the variation of critical acceleration with time. Finally parametric studies were carried out by using the method derived here, and their results are explained briefly.

Comprehensive experimental and analytical studies have been conducted over the past decades on cap beam-to-column concrete bridge joints, with an emphasis on joint force transfer mechanisms based on strut-and-tie concepts. This paper presents a methodology suitable for design and assessment of bridge joints subjected to in-place seismic actions, referred to as the force transfer method (FTM). The FTM evolved from experimental and analytical studies of exterior and interior joints in concrete multiple column bridge bents. In order to assist with the practical application of this approach, several guidelines, efficient joint mechanisms and design/assessment models are also presented.