Identification of the actual excess excavation ratio (Stakhanovskaya street – Nizhegorodskaya street site)

Introduction. Redundant strain arises in buildings and structures in areas of construction work influence caused by the deep bore tunneling performed by tunnel boring machines. The strain analysis must include an excess excavation ratio that depends on the structural features of the shield, the technology of grouting mixture injection outside the lining, the counterweight pressure applied to the shield face and geotechnical conditions so that excessive settlement could be taken account of. The purpose of the article is to identify actual values of the excess excavation ratio to raise excavation and determine the values of standard averaged excess excavation to be further applied in design. Materials and methods. This paper focuses on tunnel driving between “Stakhanovskaya Street” and “Nizhegorodskaya Street” stations. The project excess excavation ratio was applied pursuant to the regulatory documents in order to perform the analysis using PLAXIS 2D and PLAXIS 3D software packages. The method of sequential iteration was applied to identify the value of excess excavation in line with the actual settlement of buildings and structures obtained by means of monitoring. Results. The analysis has shown that the actual excess excavation ratio varies between 0.1 and 1.2 % for this construction site which is below the values required by the regulatory documents. As for the 3D setting, the values of actual excess excavation ratios are 2 to 4 times higher than those obtained for the 2D setting, although the value of the actual building settlement remains the same. Conclusions. Since the actual building settlement is smaller than the projected one, the cost of deep bored tunneling can be reduced by cutting the cost of protection of nearby buildings and structures within the area of tunneling influence without violating any safety requirements and also by reducing the number of buildings withing the projected area of influence, and respectively, by reducing the cost of geodetic monitoring over their displacements.

SYSTEMATIC DIRAC ANALYSES OF PROTON INELASTIC SCATTERINGS FROM AXIALLY SYMMETRIC DEFORMED NUCLEI

Relativistic Dirac coupled channel analyses using optical potential model are performed for the 800 MeV proton inelastic scatterings from 26 Mg and the results are compared with those from several other axially symmetric deformed nuclei for the systematic Dirac analyses. Employing scalar-vector model, scalar and time-like vector optical potentials in Lorentz covariant form are calculated phenomenologically by solving Dirac coupled channel equations using sequential iteration method. Dirac equations are reduced to second-order differential equations to obtain Schrödinger equivalent effective central and spin-orbit optical potentials and it is found that the heavier deformed nucleus has the larger effective central potential strength. Using the first-order rotational collective model to describe the low-lying excited states of ground state rotational band in the deformed nuclei, deformation parameters for the excited states are calculated and it is observed that the lighter deformed nucleus has the larger deformation parameter for the lowest lying excited 2+ state at the 800 MeV proton inelastic scattering, indicating the stronger coupling to the ground state compared to that of heavier nucleus.

Sequential Iteration of Interactive Arguments and an Efficient Zero-Knowledge Argument for NP

<p>We study the behavior of interactive arguments under sequential iteration, in particular how this affects the error probability. This problem turns out to be more complex than one might expect from the fact that for interactive proofs, the error trivially decreases exponentially in the number of iterations.<br />In particular, we study the typical efficient case where the iterated protocol is based on a single instance of a computational problem. This is not a special case of independent<br />iterations of an entire protocol, and real exponential decrease of the error cannot be expected, but nevertheless, for practical applications, one needs concrete relations<br />between the complexity and error probability of the underlying problem and that of the iterated protocol. We show how this problem can be formalized and solved using the<br />theory of proofs of knowledge.<br /> We also prove that in the non-uniform model of complexity the error probability<br />of independent iterations of an argument does indeed decrease exponentially - to our knowledge this is the first result about a strictly exponentially small error probability in a computational cryptographic security property. <br />As an illustration of our first result, we present a very efficient zero-knowledge argument<br />for circuit satisfiability, and thus for any NP problem, based on any collision-intractable hash function. Our theory applies to show the soundness of this protocol. Using an efficient hash function such as SHA-1, the protocol can handle about 20000 binary gates per second at an error level of 2^−50.</p><p>Keywords -- Interactive proofs, arguments, proofs of knowledge, computational security,<br />efficient general primitives, multi-bit commitment, statistical zero-knowledge.</p>