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    <title>Transport Research International Documentation (TRID)</title>
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
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    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Stability Analysis of the Pressurized 3D Tunnel Face in Anisotropic and Nonhomogeneous Soils</title>
      <link>https://trid.trb.org/View/1686593</link>
      <description><![CDATA[This paper investigates the effect of the anisotropy and nonhomogeneity of soil on the three-dimensional stability of a pressurized tunnel face. A three-dimensional horn failure mechanism was constructed. The energy dissipation of the ultimate limit state was analyzed, and the upper bound solution of collapse pressure was obtained according to the limit analysis theory. The validity of the proposed method was demonstrated by comparing its results with those from other researchers. The difference in collapse pressures at linear variation cohesion and average equivalent cohesion was analyzed in detail. It was found that the anisotropy and nonhomogeneity of soil cohesion have a great impact on the collapse pressure and failure scope of a pressurized tunnel face and thus should be properly considered in the support design of pressurized tunnels. In addition, an approximate solution for the collapse pressure of a tunnel face in nonhomogeneous soils is proposed based on Terzaghi’s method, which provides a simple method to quickly and effectively assess the stability of a pressurized tunnel face.]]></description>
      <pubDate>Fri, 28 Feb 2020 10:11:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1686593</guid>
    </item>
    <item>
      <title>Safe Range of Retaining Pressure for Three-dimensional Face of Pressurized Tunnels based on Limit Analysis and Reliability Method</title>
      <link>https://trid.trb.org/View/1566714</link>
      <description><![CDATA[Based on the existing research, the 3D active and passive failure mechanisms of a pressurized tunnel face are constructed. The nonlinear failure criterion is introduced into the limit analysis by virtue of the tangent technique. By neglecting the randomness of soil parameters, the collapse pressure of active failure and the blowout pressure of passive failure, namely the lower and upper limit of retaining pressure, are obtained along with the failure ranges. On account of the randomness of soil properties, a three-dimensional stochastic model of a pressurized tunnel face is established, and the optimal range of retaining pressure of the pressurized tunnel face is presented on the basis of the multiple correlated failure modes. Taking Changsha Metro Line 2 as an example, the good agreement of the measured data in situ with the reasonable range of retaining pressure verifies the presented method. The combination of limit analysis and reliability method can provide more scientific and reasonable support parameters for the construction of pressurized tunnels in the future.]]></description>
      <pubDate>Thu, 20 Dec 2018 15:33:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/1566714</guid>
    </item>
    <item>
      <title>Design Methodology to Evaluate Hydraulic Jacking in Pressure Tunnels</title>
      <link>https://trid.trb.org/View/1559673</link>
      <description><![CDATA[This paper presents methodology and tools for use in evaluation of potential hydraulic jacking in the concrete-lined section of a pressurized headrace tunnel immediately adjacent to a steel-lined tunnel section. The locations of potential in situ stress deficiency in the rock mass are uncertain but could be located in the transition section. Therefore, the performance of reinforced concrete-lining in the transition zone and elsewhere are evaluated for hydraulic jacking. The evaluation of hydraulic jacking was performed by using finite element method (FEM) and discrete element method (DEM). The computer programs ABAQUS and UDEC were used for FEM and DEM analyses, respectively. In addition to the analytical approach, a review of the available approaches focusing on the performance of concrete-lined pressure tunnels was performed. The response of the tunnel system including the lining and surrounding rock mass was evaluated for various scenarios. The evaluation includes: (1) extent of hydrojacking; (2) exfiltration from the tunnels; and (3) structural stability of the tunnel system. A series of sensitivity analyses were performed using numerical modeling to parametrically evaluate the influence of rock mass joint variations on the results.]]></description>
      <pubDate>Tue, 20 Nov 2018 10:24:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1559673</guid>
    </item>
    <item>
      <title>A Simplified Solution for Stresses Around Lined Pressure Tunnels Considering Non-Radial Symmetrical Seepage Flow</title>
      <link>https://trid.trb.org/View/1446363</link>
      <description><![CDATA[In this paper, an analytical method, for calculating seepage induced stresses and displacements in underwater lined circular pressure tunnels, is developed on the basis of a generalized effective stress law. The problem is considered as axisymmetric, and the lining and rock mass are assumed to be elastic, homogeneous and isotropic. The solution accounts for the seepage forces with the steady-state flow and hydro-mechanical pressures between adjacent zones. The proposed method can be applied for the analysis and design of pressure tunnels with concrete lining, prestressed concrete lining, grouted rock mass, as well as for the analysis of pressure tunnels considering the effects of the surrounding fractured or damaged zone. Illustrative examples are given to demonstrate the performance of the proposed method, and also to examine the effect of seepage forces on stability of pressure tunnels. It is concluded that, the classic solutions (Lame’s solution), that is based on considering the internal pressure as a mechanical load applied to the tunnel surface, is not applicable to pervious media and results in unsafe designs.]]></description>
      <pubDate>Mon, 27 Feb 2017 09:38:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1446363</guid>
    </item>
    <item>
      <title>Three-Dimensional FEM Parametric Analysis of Stiffened Steel Liners in Hydroelectric Pressure Tunnels</title>
      <link>https://trid.trb.org/View/1370053</link>
      <description><![CDATA[The availability of tools for safety evaluation of a pressure liner is a relevant issue in both structural and hydraulic engineering. Parametric studies for assessing the stability of stiffened steel liners in hydroelectric pressure tunnels, as well as practical design guidelines, are presented in this paper. First, a review of the design methods for steel liners is outlined, with certain key aspects for the critical buckling load assessment of a steel pressure liner being considered. The methodology involves three-dimensional (3D) nonlinear finite element modeling procedures, in which liner constraining and the presence of stiffeners are taken into account. In addition, both large displacements and a surrounding elastic medium are assumed in the model.]]></description>
      <pubDate>Mon, 28 Sep 2015 15:02:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1370053</guid>
    </item>
    <item>
      <title>Extension of CSRSM for the Parametric Study of the Face Stability of Pressurized Tunnels</title>
      <link>https://trid.trb.org/View/1112224</link>
      <description><![CDATA[The Collocation-based Stochastic Response Surface Methodology (CSRSM) is a powerful probabilistic method. It aims at replacing a complex deterministic model by a simple analytical expression (called meta-model) to reduce the time cost of the classical probabilistic methods. The meta-model is based on a Polynomial Chaos Expansion (PCE). The coefficients of the PCE are computed in this paper by regression from the response of the deterministic model at a limited number of collocation points. The conventional formalism of CSRSM requires performing a new set of deterministic computations each time the probabilistic parameters of the input random variables are slightly modified. An extension of CSRSM is therefore proposed in this paper. It allows the realization of a parametric study at a limited time cost without loss of accuracy. This is demonstrated by comparing the results obtained from the original CSRSM and its extension when performing a parametric study concerning the stability analysis of a pressurized tunnel face.]]></description>
      <pubDate>Wed, 30 May 2012 15:01:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1112224</guid>
    </item>
    <item>
      <title>Study on Behavior and RCFEM Designing of Restricting Crack Width of Circular Pressure Tunnel Lining</title>
      <link>https://trid.trb.org/View/1110289</link>
      <description><![CDATA[Behavior of circular pressure tunnel lining is analyzed by reinforced concrete finite element method (RCFEM) and following characteristics are found: the maximum width dose not occur at the highest head; cracking hydraulic head increases while surrounding rock have larger deformation modulus, but the maximum crack width do not vary apparently; crack width in lining can be controlled effectively while inner reinforcement is more than outer reinforcement and there are steel bars in the middle of lining; lining bears less forces actually after cracking than linear calculation because of the loss of stiffness; the reinforcement of lining is determined by the crack width control requirement, but existing formula of crack width are not appropriate for lining of tunnel. On the basis of above characteristics, RCFEM is suggested for lining design. The key of the method is that crack width is calculated by FEM directly and amount and distribution of steel bars are determined by allowed maximum crack width. Finally, by an example, the process of lining reinforcement designation by RCFEM is illustrated and the reasonableness of the stress limitations of steel bar is verified.]]></description>
      <pubDate>Mon, 08 Aug 2011 14:25:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/1110289</guid>
    </item>
    <item>
      <title>UNDER PRESSURE AT TYIN</title>
      <link>https://trid.trb.org/View/728595</link>
      <description><![CDATA[The Tyin tunnel in central Southern Norway is being upgraded to meet needs of expanding aluminum factories, but it is still using the proven technology of unlined tunnels through good quality rock. The newest upgrade will increase the annual output to 1398Gwh, up from 1180Gwh. The water passing through the tunnel powers a power plant that in turn powers nearby aluminum-production facilities. The system is based on the unlined pressure tunnel, which requires sufficient rock overburden to withstand the pressure of the water.  Tests of the rock showed it was stronger than needed, permitting the power station to be moved slightly closer to the surface without sacrificing safety. The headrace has 4 km completed and concreting has begun. Water filling is planned for July 2004 and power production is to start in October.]]></description>
      <pubDate>Tue, 03 Dec 2002 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/728595</guid>
    </item>
    <item>
      <title>DESIGN GUIDELINES FOR CONCRETE LINED PRESSURE TUNNELS</title>
      <link>https://trid.trb.org/View/539246</link>
      <description><![CDATA[This paper presents design guidelines for concrete lined pressure tunnels.  It reviews and updates design methodologies, discusses existing concrete crack formulae, proposes a crack formula for immature concrete for pressure tunnel designs, suggests critical reinforcing ratios for crack control, and presents a qualitative observation for the lining-ground-crack interaction phenomenon.  Mathematical proofs and laboratory tests can probably justify this observation in the future.  It concludes that the critical issues for pressure tunnels are the hydrojacking and hydrofracturing of the ground and the seepage and leakage of water through lining to the ground causing tunnel and ground instability.  It also concludes that high quality concrete practice is more important than crack predictions, and the preferred rebar location, for pressure tunnels, is at the outer face of a tunnel lining.]]></description>
      <pubDate>Tue, 22 Sep 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/539246</guid>
    </item>
    <item>
      <title>BEHAVIOR OF PRESSURE TUNNELS AND GUIDELINES FOR LINER DESIGN. DISCUSSION AND CLOSURE</title>
      <link>https://trid.trb.org/View/458239</link>
      <description><![CDATA[A discussion of a paper with the aforementioned title by Gabriel Fernandez, published in this journal (Volume 120, Number 10, October 1994), is presented.  Discusser Swiger discusses the two rules of thumb for determining length of steel liners in pressure tunnels.  Swiger provides examples of undesirable behavior of pressure tunnels, supporting the author's purpose in establishing a valid analytical framework to extrapolate precedent. Discussion is followed by closure from the author.]]></description>
      <pubDate>Sun, 24 Mar 1996 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/458239</guid>
    </item>
    <item>
      <title>ROLE OF TOPOGRAPHY AND ANISOTROPY WHEN SELECTING UNLINED PRESSURE-TUNNEL ALIGNMENT</title>
      <link>https://trid.trb.org/View/452386</link>
      <description><![CDATA[The authors of this paper show how analytical solutions can help in the selection of the alignment of unlined pressure tunnels near slopes and valley walls.  The proposed solutions predict in-situ stresses in rock masses with smooth and irregular topographies.  The technique can be applied to ridges and valleys in isotropic or anisotropic rock masses subject to gravity or to combined gravitational and tectonic loading.  The two-dimensional analytical solutions assume plane or generalized plane strain and can be used to substitute existing design charts for pressure tunnels based on the finite-element method.  The authors found that the safe alignment of unlined pressure tunnels depend largely on the extent of tensile regions in valley walls, which itself depends on parameters such as valley geometry, the degree of rock anisotropy, the orientation of the planes of rock anisotropy, and the in-situ loading conditions.]]></description>
      <pubDate>Mon, 18 Dec 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/452386</guid>
    </item>
    <item>
      <title>BEHAVIOR OF PRESSURE TUNNELS AND GUIDELINES FOR LINER DESIGN</title>
      <link>https://trid.trb.org/View/409829</link>
      <description><![CDATA[Understanding the behavior of pressure tunnels is important, particularly in light of recent failures.  The cost of remedial measures, including the loss of revenues during implementation, is substantial.  This paper offers a framework for evaluation of the behavior of unlined and lined tunnels, taking into account the hydraulic and mechanical interaction of the liner and surrounding media.  A systematic review of the technical factors that dictate pressure tunnel design is provided, as are design guidelines to accommodate a wide combination of rock-mass characteristics, topography, ground-water level, and operating conditions.]]></description>
      <pubDate>Tue, 18 Oct 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/409829</guid>
    </item>
    <item>
      <title>SEEPAGE-INDUCED EFFECTIVE STRESSES AND WATER PRESSURES AROUND PRESSURE TUNNELS</title>
      <link>https://trid.trb.org/View/384635</link>
      <description><![CDATA[In this research, the effective stress distribution induced by seepage from a pressure tunnel into a fractured rock mass was studied assuming that the mass can be modeled as a porous elastic medium.  The distribution of effective stresses along a radius intersecting the springline of the tunnel was estimated from closed-form solutions derived for the simplified case of negligible circumferential seepage forces in the medium.  The validity of the simplification was determined using the finite element method.  The study results led to recommendations for the establishment of minimum cover criteria in pressure tunnels, and a basis for reevaluating the methodology used to determine the minimum in-situ stress from hydrojacking test results.]]></description>
      <pubDate>Tue, 25 Jan 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/384635</guid>
    </item>
    <item>
      <title>TWIN RIVERS HARNESSED FOR MEXICAN HYDROPOWER</title>
      <link>https://trid.trb.org/View/366042</link>
      <description><![CDATA[The Zimapan hydroelectric scheme, located 120 km northwest of Mexico City, will, upon its completion in 1994, be capable of generating 1292.4 GWh/year of power. The construction site, measuring 22 km from end to end, consists of a 210 m-high dam, a 0.6 km spillway, 28 km of tunnels, a pressure shaft, a surge chamber, a power house and a network of penstocks.]]></description>
      <pubDate>Tue, 30 Jun 1992 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/366042</guid>
    </item>
    <item>
      <title>BUCKLING OF SMOOTH LININGS OF PRESSURE SHAFTS AND TUNNELS</title>
      <link>https://trid.trb.org/View/295945</link>
      <description><![CDATA[Based on the state of the 'second order stress' to establish the total potential energy functional after the deformation of the pipe wall and according to the condition at first order variation is zero (i.e. the total potential energy takes a stationary value), this study derives the differential equation of the deformation of the pipe wall with the initial noncircularity.  Then, the term of the initial noncircularity is introduced into Anstutz's formula in 1969 by applying the limit equilibrium condition mentioned previously.  In addition, according to the assumption that the second-order variation of the total potential energy is zero (i.e. the total potential energy takes the limit value), the equation of the critical external pressure for the elastic instability of the pipe wall is derived in the paper and it is proven that it is always larger than the former critical external pressure value.]]></description>
      <pubDate>Wed, 31 May 1989 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/295945</guid>
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